Brewing is the art of preparing an exhilarating or intoxicating beverage by means of a process of fermentation; but at the present day the term is usually limited to the manufacture of different kinds of beer, from infusions of malt or of grains.
In all countries, savage and civilized, one kind or other of exhilarating or intoxicating drink is prepared. In the warmer regions of the globe the juice of various palm trees is extracted, and, when fermented, forms the favourite beverage. Over all the warmer regions of South America, and in Mexico, the universal drink is Pulque, the fermented juice of the American aloe (Agave americana). Guaroa, a favourite drink with the negro races, is the fermented juice of the sugar-cane; and when the sugar-cane is not in season, these races prepare fermented drinks from honey and from rice. In many northern countries, and even occasionally in the highlands of Scotland, the juices of the birch, maple, or ash, are fermented and form a palatable drink. Kowas, the intoxicating beverage of the Mongols and the Tartars, is the fermented milk of the mare. In countries favourable to the growth of the vine, wine is the usual beverage. The Peruvians and many other Indians prepare their favourite intoxicating drink, chicha, from maize. The Arabians, Abyssinians, and several tribes in Africa, prepare their fermented drinks, bousa, from the flour or bread made from teff (Poa abyssinica); but the durria or millet (Sorghum vulgare), and even barley itself, are occasionally substituted for the teff to prepare the muddy sour bousa. The universal Russian beverage keass or quass, a sharp, acid, muddy liquid, almost the same in taste and appearance as "bousa," is made by mixing rye-bread or rye-flour, or sometimes barley flour, with water, and fermenting it. The well-known national German drink, the weiss-bier, is prepared from a fermented infusion of wheat malt with only a sixth part of barley malt. But over almost all the civilized world, the fermented infusion of barley malt, seasoned or not with hops or other bitters, when it takes the name of beer, is the favourite beverage.
All ancient Greek writers agree in assigning the honour of the discovery of beer to the Egyptians; but from the circumstance of no notice being taken of beer in the books of Moses, it has been rather rashly concluded that such a drink was unknown to them till after his death. This, however, is unlikely. The vine was alone cultivated in Egypt in those districts which were beyond the reach of the inundations; and the quantity of wine raised being limited was reserved for the rich, while the poorer classes had to content themselves with a cheaper drink prepared from barley. Herodotus, who wrote about 450 years B.C., is perhaps the earliest writer who gives any particulars regarding Egypt, and he describes beer prepared from barley as the ordinary drink of the Egyptians in his day. Pliny, Aristotle, Strabo, and others, who mention that this beer was known by the name of Zythos, give full descriptions of its qualities and intoxicating properties; and Diodorus even affirms that some kinds were so palatable as to be scarcely inferior to wine. The researches of Sir J. G. Wilkinson relative to the ancient Egyptians have thrown much light on this subject, and render it probable that beer was used as a drink by the ancient Egyptians nearly as early as wine itself. Xenophon, in his account of the retreat of the ten thousand Greeks 400 years B.C., mentions that the inhabitants of Armenia used a fermented drink made from barley. Diodorus Siculus states, that the nation of Galatia prepared a fermented drink from barley, styling it zythus, like the Egyptians. Beer was distinguished among the Greeks by a variety of names. It was called οἶνος κρασίς (barley wine), from its vinous properties, and from the material employed in its formation. In Sophocles, and probably in other Greek writers, it is distinguished by the name of βρύον. Dioscorides describes two kinds of beer, to one of which he gives the name τεῖς, and to the other σοῦπα; but he gives no description of either sufficient to enable us to distinguish them from each other. Both, he informs us, were made from barley, and similar liquors were manufactured in Spain and Britain from wheat.
Tacitus informs us that in his time beer was the common drink of the Germans, and from his imperfect description of the process which they followed, it is not unlikely, or rather there can be no doubt, that they were acquainted with the method of converting barley into malt. Pliny gives us some details respecting beer. He distinguishes it by the name of cerevisia or cereisia, the appellation by which it is known in modern Latin works.
This beverage does not appear to have come into general use in Greece or Italy; but in Germany and Britain, and some other countries, it appears to have been the common drink of the inhabitants in the time of Tacitus, and probably long before. It has continued in these countries ever since; and great quantities of beer are still manufactured in Germany, the Low Countries, and Britain. We might quote numerous passages from the narratives of recent travellers to show that the use of a drink prepared from barley is nearly universal over the northern and temperate parts of Europe and Asia. One of the latest of these travellers, M. Huc, the French missionary, remarks that the drink of the farmers in Tibet is "a sort of sharp drink made with fermented barley, which, with the addition of hops, would be very like our beer."
The first treatise published on the subject, so far as we know, was by Basil Valentine. This treatise, according to Boerhaave, is both accurate and elegant. In the year 1585, Brewing. Thaddeus Hagecius ab Hayek, a Bohemian writer, published a treatise entitled *De Cerveisia ejusque conficiendi ratione, natura, viribus et facultatibus*. This treatise, consisting only of fifty pages, is written with great simplicity and perspicuity, and gives a wonderfully accurate description of the process of brewing. In the earlier part of the eighteenth century, Mr Combrune, a practical London brewer, published a work entitled *The Theory and Practice of Brewing*. Mr Combrune appears to have the merit of having first showed the value of the thermometer in brewing. Before his day it never appears to have been used, and it was not till towards the end of the century that brewers could be persuaded to make use of what they deemed a scientific toy. As might be expected, Mr Combrune's theory of brewing appears to us, with our modern knowledge, very unsatisfactory; and, from the same cause, his experiments on the heats at which malts are coloured are of no value at the present day. He did not attend to the fact, that when the water is properly expelled from the malt before the heat is raised, it can endure, without being coloured, a much higher heat than if the heat be raised upon it while it is yet full of moisture. His work, however, did much to advance the art, and ran through several editions.
In the year 1784, Mr Richardson of Hull published his *Theoretic Hints on Brewing Malt Liquors*, and also *Statistical Estimates of the Materials of Brewing, showing the use of the Saccharometer*. These works are reprehensible on account of the air of mystery with which the subject is invested, and the avowal of the author that he conceals certain parts of the processes. Mr Richardson, however, deserves praise for the invention of the saccharometer, which he appears to have been the first to have brought publicly before the notice of the brewer. It is, however, disputed whether the merit of suggesting the use of the hydrometer to ascertain the strength of the wort is due to him or to Mr Baverstock. Mr Baverstock first endeavoured to regulate the strength of his worts by the hydrometer in 1768, and had arrived at such satisfactory results by the year 1770, that in February of that year Mr Thrale, the celebrated brewer at Southwark, and friend of Dr Samuel Johnson, gave Mr Baverstock a certificate of its value in ascertaining the strength of worts in brewing, from experiments conducted by Mr Baverstock in his (Mr T.'s) brewery. It was not, however, till Nov. 1785, that Mr Baverstock published his *Hydrometrical Observations and Experiments in the Breweries*; so that Mr Richardson has the merit of first bringing his altered hydrometer, which he termed saccharometer, before the notice of the public.
The saccharometer is an instrument essential to every brewer, to enable him to ascertain the strength of his wort, and the proportion of saccharine or fermentable matter which it contains. Mr Richardson's saccharometer was constructed on the principle that a barrel of water of 36 gallons weighed 360 lbs., and that if that quantity of water were converted into wort, and again weighed, the difference would show the weight of extractive matter which had been dissolved out of the malt. His saccharometer, therefore, was graduated so as to exhibit one degree for every pound weight which a barrel of wort weighed more than a barrel of pure water. His indications, however, were not quite correct, because he did not advert to the fact, that if a certain number of pounds weight of saccharine matter be dissolved in water, they will displace a certain bulk of water, so that the barrel of water when converted into wort, will fall short of the anticipated weight by the weight of water displaced, and for which there is no room in the barrel.
Various saccharometers have therefore been constructed with the view of correcting this error, and the different ones now in use may be classed under two heads, according to the modes in which their scales are calculated. 1. Those constructed on Richardson's principle of showing the difference in weight between a barrel of pure water, and the same water converted into wort, but making allowance for the water displaced—such are the saccharometers of Dring and Fage, and of Long. 2. Those constructed on the principle of indicating the specific gravity of the wort, that of pure water being reckoned 1000—such are the saccharometers of Allan in Scotland, and of Bate in England. There cannot be a doubt that the latter are the more correct in principle; and, accordingly, Allan's and Bate's instruments are the legal saccharometers for excise purposes in Great Britain. It is easy in practice to reduce, in a general way, the indications of the one saccharometer to that of the other. If we wish to reduce the specific gravity, as indicated by Allan's or Bate's instruments, to Dring's or Long's scale, we have only to divide the specific gravity by 2.77; and, on the other hand, if we wish to convert the indications of Long's scale into the specific gravities of Allan, we multiply the indicated pounds by 2.77.
The first step in the application of science to brewing having been thus made by the use of the thermometer to regulate the temperature, and of the saccharometer to regulate the strength of the wort, the next step was to have the various processes of malting the barley, mashing or infusing it, and fermenting the infusion, or "wort," as it is termed, investigated by scientific men, in order that the scientific principles on which the whole operations of brewing were dependent might be discovered, and made known to the brewer for his guidance. The able report on malting and brewing by Drs Hope, Coventry, and Thomson, to the Board of Excise in Scotland, ordered by the House of Commons to be printed 6th June 1806, was the first great step taken in this country to get science to bear on the operations of the brewer. Independent researches, meanwhile, were carried on by scientific men into various points which bore on that trade, and the researches of Gay-Lussac and Thenard, of Einhoff, Vogel, Saussure, Proust, Brande, Ure, Payen and Persoz, Edwards, T. Thomson and R. D. Thomson, Johnston, Liebig, &c., have combined to explain every chemical change which takes place in barley during its conversion into malt, and the various changes which occur in its infusion during the mashing, boiling, cooling, and fermenting. Scientific research has thus been brought to bear on every process of malting and brewing, and has thus been enabled to explain most of the causes of failures in any part of these processes, and lay down rules for their regulation.
Among the best of practical writers who during the present century have published treatises on malting and brewing, only two seem to require special notice. Mr William Black has the merit of having directed the attention of brewers to the influence of electricity and electro-chemical action in preventing the fermenting process going on regularly, and has convincingly shown that in many cases the irregularity in the process of fermentation, and the consequent more or less complete destruction of the beer, was caused by electrical currents being induced from faulty isolation of the fermenting tun, from chains of pipes of different metals communicating with the tun acting on its contents like a galvanic circle, from the tubes or stopcocks used being of different metals, &c. In his treatise he gives instances where this occurred, and was remedied by removal of the cause. Mr Tizard, endeavouring still further to carry the suggestions of science into the practical department of brewing, has left the beaten track altogether, and has employed his talents in inventing and in patenting many new pieces of machinery for the purpose of carrying out his peculiar views. So long as he keeps strictly to the results to which scientific research has led he goes right, but the moment he leaves these he blunders, and recommends visionary and impracticable plans which could only end in disappointment. His suggestion, that in every case there should be but one mash, but that mash be continued for six hours at a regulated temperature, is quite borne out by scientific re- Brewing searches, and cannot fail to reward the brewer who follows it out. As to his patent machine for regulating the heat, &c., we think in most cases it could be dispensed with. His second valuable suggestion, of which we quite approve, is the boiling or rather infusing at a boiling temperature the hops by themselves, and when their strength is exhausted running the wort through them in the hop-back. Here we think his coil of steam tubes could be adopted with advantage. And the only other of his suggestions and practices which seems worthy the attention of the practical brewer, is to give up boiling the wort altogether, and run the wort from the mash-tun through the hop-back at once to the coolers or through refrigerators. All these practical suggestions conform strictly with the latest scientific investigations as to the action of the different ingredients found in the infusion of malt on one another; and if Mr Tizard did nothing more than reduce these successfully to practice, he would deserve the warmest thanks of the trade. We would caution brewers, however, against adopting or following his plans relative to underground chambers for his fermenting tuns, &c. Such would but increase the evils relative to electrical agency, &c., indicated by Mr Black as so injurious.
Barley is the seed of various species of Hordeum, which have been cultivated from time immemorial. Two species of hordeum are cultivated in Britain. The first is the Hordeum distichon, or barley in which the seeds are disposed on the spike in two rows. This is the species usually cultivated in England, and in the southern parts of Scotland. The second is the Hordeum hexastichon, variously styled over Scotland bere and big. In this species the grains are really disposed in two rows, but as three seeds spring from the same point, the head appears to have the seeds disposed in six rows. It is often misnamed, "four-rowed" barley. Big is a much more hardy plant than barley, and ripens more rapidly. Hence it thrives better than barley in cold high situations. It is on this account that in the higher districts of Scotland it is sown in preference to barley. A third species of barley, the Hordeum gymnoherasticum, though apparently little known in Britain, is the prevailing kind in the north of Europe, and is said to be the hardiest of all. There are many varieties of the two-rowed barley, but those most in repute at present are the Chevalier and the Annat barleys.
The late Dr Thomson of Glasgow published elaborate tables of the weight, specific gravity, length, breadth, &c., of the grains of different kinds of barley. The general result of his experiments was, that the average weight of the Winchester bushel was 507 lb. (i.e. 52 lb. the imperial bushel); and the average weight of a Winchester bushel of big, 463 lb. (i.e. 474 lb. the imperial bushel). The specific gravity of English barley was 1:280; of Scotch barley, 1:310; and of big, 1:247. The average length of the corn of the best English barley was 0:343 of an inch; of the best Scotch 0:346 of an inch; and of big 0:324 of an inch; so that the average of all his measurements gave as nearly as might be the exact third of an inch, which it ought to be, according to the origin of our measures, as commonly stated. In consequence of the improvements in agriculture, and the introduction of new varieties of grain, the average weight of the barleys is now considerably higher than that ascertained by Dr Thomson. The average weight of the best barley in the Haddington and Edinburgh corn markets is now 54 lb. per imperial bushel; the top barleys being up to 57 and 58 lb. The cuticle or skin of the grain forms very nearly a sixth of the weight of the grain both in English and Scotch barleys. In big, however, it constitutes between a fourth and a fifth of the entire weight of the corn.
According to Einhoff, 1000 parts of barley-flour contain 720 of starch, 100 of water, 68 of fibrous or ligneous matters, 56 of sugar, 50 of mucilage, 366 of gluten, 12-3 of vegetable albumen, and 2-5 of phosphate of lime. Professor Johnston found barley-flour to contain in addition a quantity of fatty matter which has somewhat the flavour of spirits prepared from raw grain. His analysis gave in the 100 parts of barley-flour, starch 68, water 14, gluten, albumen, &c., 14; fatty matter 2, saline matter or ash 2.
It is customary to convert barley into malt previous to using it in the manufacture of beer; and in order to understand the reason of this, it is necessary to explain the changes which malting effects on the substances which enter into the composition of barley. It may be shortly stated that malting consists in exciting the grains of barley to germinate, stopping this germination at a certain stage, and then drying them in a kiln so as to enable the malt to be stored up till it is wanted.
When germination or sprouting has been excited in a grain or corn of barley, besides other, three important changes occur. First, there is formed at the base of the sprout a new substance not previously existing in the grain, to which the name diastase has been given. The exact composition of this has not yet been accurately ascertained, but it is generally considered to be a form of transformed gluten. Secondly, acetic acid (vinegar), not previously existing, is also found in the grain. And, thirdly, the insoluble starch is found more or less completely changed into soluble gum, to which the name dextrine has been given. This change of the insoluble starch into the soluble dextrine is mainly produced through the agency of the diastase, aided no doubt by the acetic acid. But this is not all. The combined action of the diastase and acetic acid on the dextrine causes it gradually to become sweet, and assume the form of sugar; and because its chemical properties then resemble the sugar which naturally exists in grapes, the name grape sugar has been given to it. Then is the function of the diastase and acetic acid in the process of germination, and of course in malting, to convert the starch into sugar, and thus prepare it for undergoing the brewer's fermenting process, which changes it into alcohol. In all these changes the diastase is the most important agent, and experiment has shown that one part of diastase can convert 2000 parts of starch into grape sugar.
Now all these conversions of starch into dextrine and grape sugar may be imitated by several simple chemical processes. Thus, exposing starch gradually to a heat of 300°, changes it into dextrine (starch-gum, and British gum, as it is called by the calico-dyers, who use it largely), and the gum thus prepared has often a sweet taste, from some of it having passed into the form of grape sugar. When starch and water are boiled together, the boiling converts the starch into dextrine (it is this with which linens are stiffened), but if the boiling be continued for some time, the fluid will be observed to get thin and watery, and acquire a sweet taste from the dextrine assuming the form of grape sugar. By boiling starch in dilute sulphuric acid the same change is effected, and the solution may be obtained pure by adding chalk or lime, which combines with and carries down the acid. This transformation is very rapidly effected if the agency of the acid be increased by elevation of temperature. Thus, 1 lb. of commercial sulphuric acid mixed with 600 lb. of water, will convert 100 lb. of starch into grape sugar in three hours if the temperature be raised by pressure to 250°. This process is actually extensively followed in France with potato starch, for the purpose of subsequently fermenting it and converting it into brandy.
Starch and dextrine have exactly the same chemical constitution, being composed of 12 atoms carbon, 10 atoms hydrogen, and 10 atoms oxygen. Grape sugar, again, is composed of 12 atoms carbon, 11 atoms hydrogen, and 11 atoms oxygen; so that the difference between grape sugar and starch is simply the addition of one atom of water. We shall have occasion afterwards to notice the change which grape sugar undergoes when changed by the process of fermentation into alcohol.
It is thus apparent that the object to be accomplished by the malting of barley, is to convert the insoluble starch into the soluble dextrine and grape sugar. But in the process of malting, as we shall immediately see, barley loses a considerable portion of its solid ingredients, viz., from 8 to 12 per cent. As, however, it has been ascertained that one part of diastase is capable of converting into grape sugar 2000 parts of starch, it might be worth the brewer's consideration whether it would not be advantageous, and a saving to him, to use only a fourth or fifth part of malt, and the rest of unmalted grain. We should not propose to use raw grain as is done by the distiller, for this would impart a disagreeable flavour to the beer, but barley, which had been exposed on the kiln to a temperature of about 300°, which would insure the whole starch being converted into dextrine. That even raw grain may be used advantageously in brewing, the practice of the Edinburgh brewers at one time abundantly testified; for they brewed better small-beer from raw grain than from malt, till they were stopped by the Court of Exchequer on arbitrary grounds, with which we could not coincide.
Dr Thomson, however, showed that raw grain could not be used for the finer ales, as it imparted a peculiar and disagreeable flavour to them. This disagreeable flavour, however, we have no doubt would be quite got the better of by using barley, kiln-dried at 300°, and prove a considerable saving to the brewer.
A duty was first charged upon malt during the troubles of Charles I.'s reign. But it continued moderate till the war with France in 1803. It was then raised to the following sums per bushel:
| Year | No. of Bushels | Duty Levied | |------|----------------|-------------| | From Barley | 1847 | 30,269,963 | L.4,105,363 12 8 | | | 1848 | 31,848,455 | 4,319,446 13 10 | | | 1849 | 33,161,088 | 4,497,472 9 8 | | | 1850 | 34,423,459 | 4,668,685 9 1 |
The quantities of malt made in Great Britain and Ireland during the years ending 5th January 1853 and 1854 were respectively 5,134,061, and 5,254,968 quarters.
From the revenue returns we learn that in Great Britain in 1850, the malt license was taken out by 8362 persons; besides 18 roasters of malt, and 25 dealers in roasted malt.
Malting consists of four processes, which follow each other in regular order: steeping, couching, flooring, and kiln-drying.
Steeping takes place in a large square cistern made of wood or stone, which is filled with water to a certain height, when the quantity of barley to be malted is shot into it in successive portions, each portion being well stirred about with rakes, for the double purpose of levelling the surface of the malt and getting rid of the lighter grains which float. Within the last fifteen years the improved cultivation of the soil, and the new varieties of barleys have done away with the necessity of skimming off the light grains. When the whole quantity of barley is introduced the grains should still be covered with four or five inches of water. Some maltsters introduce the grain first into the steep cistern, and then run on the water; with the heavier barley it is of little consequence which plan is adopted. Here the barley is allowed to remain from 40 to 72 hours, according to the temperature and the kind of barley—big requiring least steeping, new barley the most. To prevent the water becoming acetic or putrid, it is advantageous to renew it once or twice during the steeping, particularly if the weather be warm. The temperature of the water should always be from 50° to 55° Fahr. During the steeping the barley imbites about half its weight of water, and increases about a fifth in bulk, that is to say, 100 lbs. of barley after steeping would weigh 147 lbs., and 100 bushels of barley would then measure about 122 bushels. The water in which the barley has been steeped acquires an odour resembling that of damp straw, and a yellowish colour from colouring matter dissolved out of the barley skin, which thereby acquires a paler hue. Some carbonic acid is at the same time evolved, which remains dissolved in the steep-water. The object of steeping the barley in the water is to furnish moisture to the farina of the grain, and prepare it for germination in the same way as the moisture of the earth would, were the grain... Brewing, sown in it. Care must therefore be taken not to continue the barley too long in the steep. Maltsters judge of this in a very simple way. If a barley-corn pressed between the finger and thumb continues entire in the husk, it is not sufficiently steeped, but if the flour can be easily squeezed out it is ready for removal. If, however, the farina exudes in the form of a milky juice, it has been oversteeped, and the barley is spoiled for malting purposes.
While the barley is in the steep-cistern it is repeatedly gauged by the excise-officer for the purpose of preventing fraud, and of calculating the quantity of malt which will probably be yielded by it. As 100 bushels of good barley usually swell to 122 bushels, or very nearly in the proportion of 9 to 11, this is allowed for in the excise measurements.
The steeping being completed, the water is drawn off from the cistern, and the barley drained, when it is transferred to the couching-frame.
Formerly the couch-frame was allowed to be constructed of moveable boards, but since the 2d July 1827 it is by law required to be made with "the sides and bottoms thereof" straight and at right angles to each other, having three of such sides permanently fixed, and the other side formed of moveable planks at least two inches in thickness, and must not exceed 28 inches in depth. In this couch-frame the barley is carefully levelled, and is not allowed to be touched for a period of 24 hours from May to August, and 26 hours from August to May, to enable the excise-officer to gauge it accurately. The malt duty is usually levied on the couch-gauge, because it is there the malt usually acquires its greatest bulk. The sole object of placing the barley in the couch-frame is to enable the excise-officer to gauge it; it is otherwise no essential stage of the malting process.
At the end of 24 hours during the summer, or 26 hours during the winter months, from the period of its removal from the steep-cistern, the barley, which has begun to acquire increase of temperature, is removed from the couch-frame, and spread on the floor in square heaps about 16 inches in depth. For several hours after the grain is in the couch-frame no perceptible increase of temperature occurs, but the moisture on the surface of the grains gradually exhales or is absorbed, so that the grains cease to moisten the hand. After this the heat gradually rises, and it is to prevent the heat increasing too rapidly, and to heat the whole grains equally, that the barley is turned out upon the floor.
On the floor the temperature of the heap gradually rises till it is about 10° above that of the surrounding air, which usually happens about 96 hours after it has been thrown out of the steep. An agreeable odour, somewhat resembling that of apples, is now exhaled, and if the hand be thrust into the heap the grains are found to have become so moist as to wet the hand. The appearance of this stage is called "sweating" by the maltsters, and it is at this stage that germination begins. Up to this period the heaps of grain had been daily turned, in order to bring all the grains equally forward, and also to moderate the heat.
If the barley is now examined, it will be found that the radicles or roots are sprouting from the tip of every grain. At first these have the appearance of a white prominence, which soon, however, increases in length, and divides itself into three or more fibrils. Unless the growth were now checked, these rootlets would increase in length with great rapidity; the great aim of the maltster, therefore, is to keep these as short as possible till the grain be sufficiently malted. For this purpose the heaps of grain are turned over at least twice every day, the grains lying at the bottom and interior of the heap being at each turning thrown to the surface. With the same view the depth of the bed of grain is also reduced at each successive turning, till at last it is reduced to three or four inches. The number and frequency of the turnings is regulated by the temperature of the malt, being more frequent the higher its temperature. In England the malt heap is generally kept at the temperature of 62°; and fourteen days is the usual period required for the grain passing through the germinating stage. In Scotland, on the other hand, the temperature of the malt heap is kept at about 55°, and the consequence is, that the grain takes from 16 to 20 days to pass through the same stages.
About a day after the rootlets appear, the rudiment of the stem, or the plumula, becomes perceptible. This is called by maltsters the "acrosire." It issues from the same end of the seed as the radicles, but, instead of piercing the husk, turns round, and proceeds within the husk to the other end of the grain. As soon as the acrosire approaches the other end of the grain, or its point has passed four-fifths of the grain, its further growth must be arrested, else it would push through the husk and appear externally as a green leaf, when the interior of the grain would become milky, and be quite destroyed for the purposes of the brewer. In well-made malt then the acrosire has only advanced four-fifths up the side of the grain under the skin, and the radicles have not been allowed to get more than one and a half times longer than the grain; and at this period the texture of the grain is so loose that it crumbles to powder under the pressure of the finger and thumb. This crumbling under the pressure of the finger and thumb is styled "the free." It is not commonly known, however, that the same condition of grain occurs on the ninth or tenth day from its being turned out of the steep, and this is styled the "first free," and if the malting be stopped at this stage it will make tolerable beer; but if it be allowed to pass this stage, the grain again becomes tough, and is quite unfit for brewing till the "second free" occurs. There can be no doubt that it is of importance to the maltster that the law now allows him to sprinkle water over the malt when on the floor. This is usually done on the sixth or seventh day if the germination should appear to be languid. This practice is getting more and more into repute,—indeed there are seasons when it would be difficult to make good malt unless moisture were thus supplied to the grains. During the whole period of germination the light should be excluded as much as possible.
It was formerly the practice before removing the malt from the floor to gather it once more into a considerable heap, in order to allow its heat to increase to 75° or 80°, under the idea of "mellowing" the malt. Even some late writers—practical men too—recommended this to be done. It is a practice which is more honoured in the breach than the observance, as it causes a useless waste, without forwarding any of the subsequent processes. By thus heating the grain, after it is ready for the kiln, the malt becomes excessively sweet, much of the dextrine is resolved into sugar, and the dry heat to which it is afterwards exposed in the kiln reacting on it, seems to convert some of it into alcohol, which is carried off and lost. There is thereby caused a sensible diminution in the weight of the malt, while there is no counterbalancing advantage gained.
As previously explained, during the malting the starch is converted into dextrine and grape sugar; and by examining barley in its different stages of germination, it has been ascertained that this conversion keeps pace with the growth of the acrosire, and advances through the grain along with it, so that all the portions of the grain to which the acrosire has not yet reached, are still in their starchy state, whilst all those parts opposite to the acrosire have their starch converted into dextrine and grape sugar. The glutinous constituents of the grain have also disappeared, being generally supposed to be taken up by the radicles. While the grain is on the floor, it has been ascertained that it absorbs oxygen, and gives out carbonic acid gas, but probably Brewing, to no great extent, seeing that the loss which the grain sustains on the floor is trifling, probably not exceeding 1½ per cent; and a considerable proportion of this must be attributed to grains bruised and roots broken off during the frequent turnings.
The last operation of malting consists in drying the malt on the malt-kiln, by which the germination is arrested, and the brewer is enabled to store up the malt until it is required. The kiln is a chamber, the floor of which usually consists of perforated iron plates of wire-cloth, and in the roof of which is a vent to permit the escape of the heated air and vapour. Under this chamber is a space in which a fire of charcoal or coke is lighted; or this part is fitted up with a proper hot-air stove in which coals may be burned, the smoke being carried away into a chimney by means of iron tubes or flues. Damper plates are in this latter case provided so as to regulate the draught through the flues, and the admission of hot air to the kiln. The malt is then spread regularly over the perforated iron floor to the depth of three or four inches, and the heated air passing through the perforated plates makes its way through the malt, and carries off its moisture, escaping at the vent in the roof. The heat to which the malt is exposed should be about 90°, and should not exceed 100° until its whole moisture is expelled. It is a remarkable fact, that if the heat be raised when the malt is still damp, even a low temperature, such as 135° or 140°, will cause it to assume a brown colour; whereas if the malt be freed from moisture at a low temperature, it may be exposed even to a heat of 170° without colouring it, and without depriving it of its vegetative power. The late Dr Thomson demonstrated this fact by first thoroughly drying malt at a temperature under 100° and then exposing it to a heat of 175°, after which he sowed it, and found it vegetated as rapidly as fresh barley. Till the moisture is thoroughly expelled by the low heat, the malt requires to be repeatedly turned; such at least is the common practice. Mr Black, however, objects to this, and asserts that if the current of heated air be sufficient, no turning is requisite till the malt be dried and the heat raised, when he turns to prevent burning. As Mr Black speaks from some experience, we quote his words. "We know that the portion of the malt nearest the covering of the kiln sometimes feels quite dry, while that on the top is quite damp; if, therefore, by turning, we throw this part of the malt upon the top and the wet to the bottom, the steam off the wet malt from below must pass through the drier malt on the top, thus creating double work. The steam also, by again passing through the drier malt on the top, tends to render it tough. If the kilns be properly constructed, turning is not only unnecessary but injurious, until the malt be nearly ready for removal from the kiln, when several turns, with a brisk fire, may be necessary to render the dryness of the malt uniform."—(P. 222.)
According to the common practice, when the moisture has been nearly expelled, the temperature is raised to from 145° to 165°, and it should be kept at this temperature till it has acquired the desired shade of colour, which is commonly a pale yellowish-brown. If the heat be raised when the malt is moist, its colour is rendered brown, or dark brown, and the quantity of soluble matter is supposed to be diminished.
In a properly regulated kiln the drying should not occupy more than two days. But if the supply of heated air be great, the whole process of kiln-drying may be finished in twenty-four hours. After this the fire is withdrawn, to allow the malt to cool, or it is removed to the floor of an adjoining apartment and allowed to cool there. Often before removing it, it is well trodden for the purpose of breaking off the rootlets, or "comings," as they are called. At this period they are very brittle and easily broken off, and they are afterwards separated from the malt by a sieve or winnowing machine.
A very objectionable practice used to prevail among many provincial maltsters who manufactured for the London market. When the malt was still hot they sprinkled it with water, for the double purpose, as they imagined, of making it mellow, and causing it to stand out to its measure when it arrived at its destination. Such malt, if kept, invariably gets "slack," as it is termed, or damp; and the worts brewed from it have a strong tendency to run to acidity. It is not profitable for any brewer to employ such malt.
There are several kinds of malt met with in commerce—pale malt, amber malt, brown malt, brown malt, and black or porter malt. The preparation of pale malt has been already described. That of amber malt consists in raising the finishing heat a little higher. Brown malt is made and prepared exactly as pale malt, excepting that before it is perfectly dried a little water is sprinkled over it when upon the kiln, and the drying is finished by rapidly raising a brisk heat under the malt, which is spread thinly on the floor and constantly stirred.
Blown malt is just a variety of brown malt, and its manufacture used to be largely followed by maltsters in and around London. The malt, when ready for the kiln, is laid thinly on a kiln floor made of wire-cloth, and is immediately dried off with blazing wood, straw, or furze, the grain being constantly turned all the time by men with wooden shovels. Malt thus rapidly dried has a swollen or "blown" appearance from the swelling of the damp farina in the grain. Its colour is also more or less brown.
Black or porter malt, called also patent malt, is the legal colouring matter used in porter-brewing. It is simply malt roasted in a cylinder of perforated iron over a fire (like coffee), till the required colour be given. Any kind of malt may be used for this purpose, so that it is usually prepared from malt which has been injured in its preparation. This kind of malt, being so often made of spoiled materials, is frequently of bad quality. Good black malt should retain its original size and shape, each grain should be separate, not adhering in clusters to each other, and its interior should have a uniform dark chocolate colour. The whole of the starchy and saccharine matters being converted into a kind of caramel, this malt does not add to the strength of the worts, but simply supplies colour and flavour. Brown and blown malts some supposed to be deficient in extractive matter to the extent of from 20 to 30 per cent., but the recent direct experiments of Professors Graham, Hoffmann, and Redwood, prove that they yield as much extractive matter as pale and amber malts.
One hundred pounds weight of good barley converted into pale malt in the above described manner, after being kiln-dried and sifted, are found on an average to weigh only 80 lb. But as raw grain, if dried at the same temperature, would, according to Dr Thomas Thomson's experiments, lose 12 per cent. of moisture, the actual loss of solid matter which the barley has sustained by malting is only 8 per cent. This loss is thus accounted for by Dr Thomson:
| Carried off by the steep water | 1½ per cent. | |-------------------------------|-------------| | Dissipated on the floor and kiln | 3 | | Roots | 3 | | Waste (bruised and lost grains) | ½ |
Dr R. Dundas Thomson, who made numerous experiments on malt for the purpose of ascertaining its feeding and fattening properties, states the loss which barley sustains in malting to be—
| Water | 6·00 | | Saline matter | 0·48 | | Organic matter | 12·32 |
Total, ........................................... 19·00 Brewing, or a loss of solid matter one-half greater than that stated by Dr T. Thomson.
Big sustains a considerably greater loss of weight than barley when malted, its average loss of weight, according to Dr Thomas Thomson, amounting to 15 per cent., that of barley, as above explained, being 8.
The bulk or volume, however, of the malt generally exceeds that of the barley used. Thus 100 bushels of English barley yield on the average 109 bushels of malt. Big, however, only yields on the average 100½ bushels of malt for every 100 of raw grain. In our last edition numerous tables were given of the actual results obtained by malting barleys of different qualities. To these the reader is referred who wishes further particulars on this point.
We still want a good analysis of malt. Proust, indeed, gives the following comparative analysis of barley and malt, but the substance he designates hordein is evidently starch with fibrous or other insoluble matters.
| Barley | Malt | |--------|------| | Resin | 1 | | Gum | 4 | | Sugar | 6 | | Gluten | 8 | | Starch | 32 | | Hordein| 56 |
Dr R. Dundas Thomson, in his interesting work, *Experimental Researches on the Food of Animals*, gives the ultimate analysis of barley and of malt, but such facts are of little interest to the brewer.
Dr Uré's analysis of barley was a purely practical one, viz., to determine the quantity of solid extract contained in malt available for the brewer's purpose; and as that is the best malt for the brewer which yields the largest quantity of extract, he recommends all malts to be tested for this before being purchased. His procedure is simple. 100 grains by weight of malt are taken, powdered, and dried for half-an-hour by the heat from boiling water. They are then weighed, and the loss in weight shows the quantity of moisture in the malt. Cold water is then poured over the powder, and the vessel containing it is heated in the steam bath, with occasional stirring, for half-an-hour. The husks and insoluble matters are then drained off and washed with boiling water; they are then thoroughly dried and weighed. Their weight gives the insoluble matter in the malt. The residue of the weight, therefore, is the weight of the soluble extract available for the brewer. As the result of several experiments on good malt, he found the average to be in 100 parts by weight—
| Moisture | 6·5 | |----------|-----| | Insoluble matter | 26·7 | | Soluble extract | 66·8 |
According to these practical experiments, if we assume that a quarter of malt weighs 324 lb., then the total soluble extract would amount to 213·84 lb. avoirdupois; but as the gum and sugar, in assuming the fluid form, combine with the elements of water, if the extract were dried it would weigh 231 lb., and, reduced to the basis of the barrel of 36 gallons, becomes in the language of the brewer 87 lb. per barrel of 36 gallons, which merely means that the wort from a quarter of malt, if evaporated down to the bulk of a barrel of 36 gallons, would weigh 87 lb. more than a barrel of pure water. These experiments of Dr Uré correspond very closely with the actual yield of extract at two of the greatest London breweries. He was informed by a gentleman connected with these breweries, that the actual average yield was 84 lb. of saccharine extract for every quart-
Besides malt, the only other solid ingredient used in brewing is the hop. This is the female catkin of the Humulus Lupulus, a plant belonging to the natural order Urticaceae, and the Linnean order Diocca pentandra. The hop was introduced into England from Flanders about the year 1524, and its cultivation rapidly increased in the southern counties. The most extensive plantations are in Kent, Sussex, and Herefordshire, but they are also cultivated successfully in several other counties. The female flowers, placed on different plants from the males, grow in ovoid cones, and consist of scales which have at their base the germ of the future seed. The fruit of the hop is a small rounded seed enveloped in a scaly calyx, which contains at its base a granular yellow substance which appears to the eye like fine dust. This secretion is the valuable part of the hop on which its peculiar properties depend, and amounts to about one-eighth of the weight of the hop. When distilled with water, this substance yields 2 per cent. of a volatile colourless oil, to which the plant owes its aroma. 52 per cent. of the powder consists of a resin soluble in alcohol; and the watery solution from which the resin has been separated consists of a peculiar bitter principle termed lupulin, mixed with tannin and malic acid. The lupulin when purified, amounts to from 8 to 12 per cent., and possesses the characteristic taste and bitterness of the hop.
The catkins of the hop ripen in September, when they are picked from the bines, and are carefully dried on kilns. They are then laid in heaps on the floor until they slightly heat, immediately on which being observed they are "bagged." This is the most important operation for the preservation of their virtues. The hops are thrown into the bags in successive layers, each layer being well trampled down; and to render access of air to the fine resinous dust of the catkins still more difficult, it is usual to compress them still further by means of a screw or hydraulic press. The valuable yellow powder with its essential oil is thus preserved for years. The best hops have a golden-yellow colour and an agreeable aroma. When rubbed between the hands they leave a yellow odoriferous powder on them without any broken parts of the plant, and they yield to boiling alcohol from nine to twelve per cent. of soluble yellow matter. This last is the best test of their good quality, and should always be made before purchasing them.
The hop is a very precarious crop, the produce of some years failing to the extent of fully two-thirds, as even the following short table will show. In 1840 the failure of the hop crop was so great, that only 7,114,917 lb. weight paid duty in England. The duty on hops is 2d. per pound, and Brewing. 5 per cent. additional. The duty however does not extend to Ireland. The following table, from the latest revenue returns, shows the number of pounds weight of hops which paid duty in England during the years 1848 to 1853 inclusive, the amount of duty levied thereon, and the number of acres of land under crop during each of these years:
| Year | Acres | Pounds of Hops | Amount of Duty | |------|-------|----------------|---------------| | 1848 | 49,232 | 44,343,984 | L.388,007 3 8 | | 1849 | 42,798 | 16,650,914 | 145,693 4 9 | | 1850 | 43,125 | 48,337,609 | 424,762 3 0 | | 1851 | 43,244 | 27,042,919 | 236,623 1 10 | | 1852 | 46,157 | 51,102,494 | 447,144 8 12 | | 1853 | 49,367 | 31,751,693 | 277,824 16 9 |
During the past year foreign hops have been largely used by some brewers, even in the manufacture of the finest descriptions of ales. In consequence, however, of not possessing the rich flavour of the English hops, they have not as yet been used alone for the finer liquors, but mixed in various proportions, from a third to a sixth, with all the best kinds of English hops. Were more attention paid to the drying and packing of these hops they would be much more largely used than at present. The prejudice, however, which formerly existed against their use is gradually dying out; and when a strong bitter is required, as in India ale, with only a certain amount of flavour, it is found that the flavour may be given by one kind of hop, and the bitter by another, without in the least deteriorating the quality of the liquor. During the year 1852 there were only 34,622 lb. weight of foreign hops imported into Britain; but during the year 1853 the imports of foreign hops had increased to 4,739,307 lb. weight.
The water used in brewing should in every case be the purest spring water which can be had. Recent chemical researches have established that many of the old notions with regard to the water are fallacious. River water when pure possesses no superiority over pure spring water; whereas if impure, or loaded with animal and vegetable matters in decomposition, as is the Thames water, it is a decided loss to the brewer, as the vegetable and animal remains are decomposed during the process of brewing, and carry with them some portion of the strength of the wort, besides rendering the wort and the beer more liable to go wrong. Waters which possess a certain amount of hardness are even not objectionable, as the earthy salts, to which the hardness is owing, are precipitated during the process of brewing; in fact, some of the finest ales are made of waters decidedly hard, but free from vegetable and animal impurity.
Brewing properly consists of five successive processes, viz., 1. Mashing; 2. Boiling; 3. Cooling; 4. Fermenting; 5. Cleansing; and to these might perhaps be added Storing and Racking.
Mashing consists in infusing the malt in water of a certain temperature; and the infusion when run off is termed the "wort." Previous to the malt being introduced into the mash-tun it must be bruised or coarsely ground, but it is now generally admitted that bruising the malt in the crushing-mill, where it is passed between two iron cylinders, answers best for the brewer's purpose. If the malt were ground it would be apt to form a cohesive paste with the hot water when it is mashed (called "setting" by the brewer), when it would be difficult to drain. In the crushed malt, however, the husk remains entire, and thus helps to keep the farinaceous particles accessible to the solvent action of the water. Crushed malt is about a fifth part greater in bulk than whole malt, or four bushels of malt after being crushed would measure five bushels. Some brewers recommend that the malt after it is crushed should be kept in a cool place for a day or two, in order that, by attracting moisture from the air, it may be more easily mashed; and Dr Ure, from experiments made for the purpose of ascertain-
ing whether this was or was not in favour of the malt, recommends the practice.
The mash-tun is a large wooden tub with a double bottom, the uppermost of which is moveable, and is pierced with holes, and is fixed a few inches above the other. Into the space between the two bottoms are fixed the ends of the tubes and stopcocks for letting in water or drawing off the wort. The mash-tun ought always to be at least one-third larger than the bulk of the malt to be used.
The temperature of the water which is let into the mash-tun is of no small importance. The researches of Payen and Persoz have demonstrated that the action of the diastase in the conversion of starch and dextrine into sugar is most perfect when the temperature is not lower than 158°, and not higher than 167°. If raised much higher, the change of the dextrine into sugar does not take place, the starch remaining in the state of dextrine. The water in the boiler is therefore usually heated to about 170° or 180°, and run into the mash-tun generally in the proportion of a barrel and a half of water (liquor, as the brewers term it) for each quarter of malt. The malt, as it is slowly poured in, is thoroughly mixed with the water by means of ears and rakes, to prevent it forming clots, which it is apt to do if the temperature of the water be high. In many breweries now a machine is fixed in the mash-tun, provided with ears and rakes which are moved by steam-power, and is found to answer well. After the malt has been thoroughly mixed, an additional quantity of warm water is thrown in from below, when the tun is covered over and allowed to remain from 1½ to 3 hours. In many of the great London breweries the practice followed is to run into the mash-tun a certain proportion of water at the temperature of 145° in summer, or 167° in winter, and gradually throw in the malt, and mix it by proper agitation so that it may be properly moistened and no lumps may remain. The quantity of water is usually in the proportion of 1½ barrel to the quarter of malt. This takes up from half an hour to three-quarters of an hour, after which about two-thirds more water (or a barrel per quarter of malt) is run into the mash at the temperature of 200°, and the agitation is renewed till the whole is thoroughly mixed. The mean temperature of the mash may be reckoned about 145°. The tun is then covered and allowed to remain at rest for an hour or an hour and a half. After this period the infusion of malt, or "wort" as it is called, is run off into a large vessel called the underback.
By this plan, if the additional water at 200° be thrown too suddenly into the mash-tun, there is danger of its destroying to some extent the chemical agency of the diastase in the conversion of the starch and dextrine into sugar. And it is a known fact that the higher the temperature of the water used for mashing, the greater is the quantity of unchanged starch in the wort.
Mr Tizard has lately endeavoured to introduce a new plan of mashing, which seems to possess considerable advantages over that in common use. He mashes the malt in water at the temperature of 160°, no matter what the temperature of the malt may be, thoroughly stirring and mixing it; the water being in the proportion of 1½ to 1½ barrel per quarter of malt. The tun is then covered for an hour and a half, to allow full time for every grain to be fully saturated. After this period, in order to raise the mash to that temperature which the researches of Payen and Persoz showed was best fitted for extracting the soluble matters, and allowing the diastase its full action in the conversion of the starch and dextrine into sugar, he heats the mash by means of steam to the temperature of from 160° to 170°. This he effects through the agency of what he calls his "mashing attenuator," which he has patented. This machine is merely the fixed rakes and ears made of hollow tubing, which he sets in circular motion by means of the steam-engine, and throws steam into them. The heat thus communicated to the mash, through the hollow rakes and oars, raises the temperature from 130° or 140° to 160° or 170° in about 20 minutes, at which temperature he maintains the mash for 4 or 6 hours according to the colour and quality of the malt, and the discretion of the brewer. Mr Tizard holds that this plan possesses several advantages over that usually followed. It converts more effectually the whole starch and dextrine into sugar, allowing the diastase to exert its full chemical power. It extracts a larger proportion of saccharine matter from the malt. And by requiring a lesser quantity of water to exhaust the malt, saves waste in the subsequent processes by requiring no boiling.
Viewed in a purely chemical light, we should say that Mr Tizard's plan seems best adapted to attain the end in view; but extended practice can alone decide. It appears to us that the essential part of his plan is the continuing the mashing for six hours, and maintaining the temperature at that height which experiment has shown will most effectually convert the whole starch into sugar.
We understand that a patent has just been taken out for a machine which will effect a great saving of labour in mashing, besides making a superior mash. The hot water and the crushed malt are poured into it in a continuous stream, and as it revolves rapidly on the principle of the barrel churn, these are thoroughly mixed together and discharged into the mash-tun without any loss either of heat or of time.
By the ordinary plan of mashing, when the first wort is drawn off into the underback, a second quantity of water is introduced into the mash-tun from below the malt, usually at the temperature of 200°, when the whole is agitated and stirred as before. The quantity of water is usually 3-4ths of that first used. It is then covered over, and allowed to stand for an hour. Many brewers now approve of making their second mash with water not exceeding 150° in temperature, and think they have improved the quality of their beer thereby.
While the second mash is making, the first drawn wort is usually pumped into the boiler, and brought to the boil as speedily as possible. When the wort from the second mash is drawn off it is pumped at once into the boiler, and mixes without stopping the boiling.
Usually a third mash is made with a still smaller quantity of water, also about 200° in temperature, and, after being covered up for half an hour is drawn off, and is either pumped into the boiler, reserved for table beer, or kept to form the first mash with fresh malt.
When three mashes are made, it is usually found that the second contains just half as much extract as the first mash, and the third mash just half as much as the second. In fact, the first mash seems to have extracted nearly the whole soluble matters, and the subsequent mashes merely dilute, and allow to be carried off, the portion of the extract which had been retained by the grains.
The Scottish-ale brewers, acting on this belief, instead of making several mashes, usually make but one, of the strength of about 1½ or 2 barrels to the quarter of malt; and, in order to procure all the extract retained by the grains, after the taps are opened below, sprinkle hot water in a continuous shower ("sparge," as they call it) over the surface of the mash. As this water percolates through the mass of grains and runs out at the tap below, it carries with it all the soluble matters of the malt. It is essential for the success of this process that the surface of the malt should never be allowed to get dry, otherwise the wet mass of grains falls into cracks, and the water escapes through them, without exhausting the malt. The sparger is a very simple instrument. It is a copper tube A B, one-and-a-half or two inches in diameter, and of sufficient length to stretch across the mash-tun. It is closed at its extremities; is divided into two equal parts A E and B E, and these have a single row of holes perforated on their reverse sides. Each arm of the tube communicates, by means of the tubes E E, with a copper cup C, which is fixed over the centre; and from the centre of this cup rises a hollow tube terminating in the handle D. When about to be used, the wooden bar G G is fixed across the mash-tun, and the upright pin P in its centre runs through the circular opening of the transverse tube, and up the hollow tube in the centre of the cup, and works on a pivot at the handle. A stream of hot water of the temperature of 180° is then allowed to pour into the copper cup, and as it escapes by the single row of horizontal holes on the opposite sides of each limb, these are turned round by the resistance which the air opposes to the horizontal jets of water, and the whole surface of the mash is continuously and regularly sprinkled.
When the malt is first mashed the infusion has a milky-white appearance; but as the mashing goes on, and the diastase reacts on the dextrine, a fine frothy head appears all over the mash; and if it be run off it is found to have become quite transparent, to have a fine amber colour, a peculiar smell, and a sweet, luscious taste. When the mash is made by first wetting the malt and then running in additional water, this change is observed to occur when the temperature is raised by the addition of the hotter water. If, however, the heat be raised too high—as, for instance, to 190° or 200°—the wort invariably runs cloudy from the mash-tun, and is found to contain much unchanged starch and dextrine. The high heat has in this case destroyed the action of the diastase.
When the mashing is performed according to the Scottish ale-brewers' plan, as the wort is run off the colour is observed to diminish, the smell to become less agreeable, and the taste less sweet. At last the colour becomes nearly opal, and the smell sour. The whole soluble portion of the malt has not, however, been profitably extracted, either by this method or by the ordinary English plan of three several mashes, as is proved by the last wort in the English method, and the last portion of the wort by the Scottish plan, containing undecomposed starch. We have not had an opportunity of examining the worts prepared according to Mr Tizard's plan; but, from the single circumstance of his infusing his malt for six hours, and keeping it during the last five of these at the temperature most favourable for the diastase converting the whole starch into sugar, we should conclude that the whole starch was converted into sugar, and that no portion would pass off undecomposed. Mr Tizard indeed gives a table, the result of numerous experiments, in demonstration of the superiority of his plan over those usually followed. By examining the mash at the end of every hour, he found that the quantity of saccharine matter was increasing up to the end of the sixth hour. Instead, therefore, of getting at the rate of only 84 lb. per barrel for every quarter of malt, he got 90 lbs.; which extra quantity, in a large brewery, must be a very large saving annually. Whatever, therefore, may be thought of his "Mashing Attemperator," there seems to be no doubt that his continuing the mashing for five or six hours is a decided improvement, and one strictly in accordance with the latest chemical researches.
By Mr Tizard's plan the diastase is left in contact with the starch and dextrine so long as to convert the whole into sugar; whereas if the diastase be drawn off with the first mash before it has had time to effect this change, the chemical powers of what is left in the mash are greatly weakened in the second mash by the running in of water at a temperature of 200°, which is known to destroy its chemical action.
If, then, the plan of lengthened infusion he adopted, the Scottish method of "sparging" is the proper mode of removing the whole of the infusion from the grains. Mr Tizard has invented and patented a machine to sparge the mash and also empty the grains out of the mash tun. It appears to us, however, to possess no advantages over the simple and Brewing: cheap Scottish sparger, besides being too complicated and too easily put out of order for any ordinary brewery.
The next part of the process is to boil the wort, and it is when in the boiler that the wort receives the quantity of hops which gives the beer bitterness and flavour, and renders it capable of being kept. Brewers in different parts of the country add their hops in different ways and at different times. Some add the hops as soon as the wort begins to boil; others wait for half an hour, when they throw in half the quantity they purpose to add, and in another half hour throw in the rest. Some brewers, after adding the hops in masses, allow them to swim on the surface that the steam may penetrate them and open their pores before they beat them down into the wort; others sink them into the wort inclosed in nets, and when they think their virtues are sufficiently extracted, draw the nets up, and allow them to drip into the boiler. As the aroma of the hop depends on the yellow powder, care should be taken not to lose it by breaking up the masses too much before adding them to the wort. The quantity of hops added to the wort varies according to the strength of the beer, the length of time it is intended to be kept, or the heat of the climate to which it is to be sent. For the strongest kinds of ale or porter, the usual proportion is 1 lb. of hops for every bushel of malt, or 8 lb. to the quarter of malt. Strong beer has about 4½ lb. per quarter, and table beer rarely more than 2 lb.; Indian ales, and beers for exportation, again, require from 12 to 22 lb. of hops to the quarter of malt.
We have said that the main object in boiling the wort is to increase its strength by driving off the superfluous water which had been added in mashing. Brewers, however, believe that other important ends are served, viz., that any residual starch should by the boiling be converted into dextrine; that the albuminous and gelatinous particles in solution may be coagulated and precipitated, partly by the heat, partly by combining with the tannin of the hops, and by this deposit tend to clarify the liquor; and that thereby the keeping qualities of the beer are improved. We shall immediately see whether any of these supposed purposes are answered. The boiling is very generally continued for three hours; but many practical brewers condemn this lengthened boiling, as thereby the finer and more aromatic principles of the hops are thrown off, and a nauseous bitter extracted. They therefore limit the boiling to an hour and a half. It seems to be an ascertained fact, that a certain portion of the saccharine extract is lost during the boiling. Whether this is carried off by the vapour, or whether the boiling converts a portion of it into alcohol which flies off along with the steam, has not with certainty been determined. The amount of condensation in boiling is usually in the proportion of 1 in 10 per hour. That is to say that wort of the strength of 50 lb. saccharine extract per barrel would strengthen 5 lb. per barrel by one hour's boiling.
When the boiling is finished the boiled wort is drawn off into a large vessel called the "hop-back," or "jack-back," which is furnished with a double bottom, the uppermost of which is of cast iron perforated with small holes, through which the wort drains and leaves the hops.
Mr Tizard objects to boiling the wort at all, condemning it as a useless and wasteful process; and, with great reason, he attributes much of the irregularities which occur during the fermenting process to injury which the wort receives in boiling. Chemical experiments have clearly demonstrated, that to undergo the fermentative stage in perfection, there should be as much gluten and albuminous matter in the wort as possible. But the boiling, and especially the boiling with the hops, is the very surest way to destroy these matters, seeing that the heat coagulates and precipitates them, while the astringent matters in the hop unite with what the heat might have spared, and throw them down as inert matter. But boiling has another hurtful effect on the wort; it quite puts an end to any further conversion of starch or dextrine into sugar, by destroying the diastase, the essential principle which effects this conversion. By boiling, therefore, all the unconverted starch or dextrine remains in the wort and subsequent beer in the state of gum, and hence the tendency to ropiness which such beer exhibits. In support of his practice of not boiling the wort, Mr Tizard refers to the fermentation of cider and wine, in neither of which is the wort boiled before being fermented, yet these liquors are as clear as beer ever requires to be.
As it is requisite, however, to extract the bitter of the hop by means of heat, Mr Tizard has patented an apparatus for the purpose. As he does not boil the wort, the underback is fitted with a false perforated bottom like that in the mash-tun, or the old hop-back plates may be used for the same purpose. Beneath this perforated false bottom, or these plates, a coil or two of metal tubing is fixed, provided with a stop-cock, and made to communicate with the steam-boiler. The hops are spread evenly over this perforated bottom, and four hours before setting tap, boiling water is poured over them sufficient to cover them. The vessel is then covered up and left for an hour. Steam is then passed through the coil of tubes below the perforated bottom till the temperature of the water rises to 200°, and it is maintained at this heat for three hours. The wort is then conveyed directly from the mash-tun to the underback; (now the hop-back), till it stands 6 inches in depth above the perforated floor. The wort is then pumped or run off into the coolers; and as the wort is running in from the mash-tun above the hops, and is draining or being pumped away from below them, all their virtues are thoroughly extracted and incorporated with the wort. In this way none of the aroma of the hop is lost; there is no destruction of saccharine matter or of the principles so necessary to a successful fermentation; and as the wort is drawn off at once, nearly at the strength it is wanted, there is no need of prolonged evaporation to bring it down to the proper density.
Lengthened experience can alone determine in which of these plans true economy consists. That Mr Tizard's plan is the most scientific, and promises to yield the best results, can scarcely be questioned. And as the essential parts of his plan could be carried out with scarcely any alteration on the present machinery, it is to be hoped brewers will give it a fair trial, and make known the result. What we consider the essentials of his plan, are the six hours' mashing, the sparging to remove the remains of the saccharine extract from the grains, the separate infusion of the hops, and the transfer of the wort direct from the mash-tun to the coolers. We are quite aware that Mr Tizard would object to this being called his plan, unless his expensive patented machinery were adopted. But we have attempted to separate the essential from the non-essential, and feel satisfied that the above fulfils all the indications which science has pointed out. The hops cause a considerable loss of wort, as every 60 lb. weight of hops is calculated to retain about a barrel of wort. Brewers seem not to attend sufficiently to this circumstance. By the use of a screw or hydraulic press, this quantity could be recovered; but most brewers prefer using these hops for the brewing of weak table-beer, to which, besides imparting some bitter, they impart considerable strength of saccharine matter. A preferable plan seems to be to prepare the infusion of hops separately, as recommended by Mr Tizard, but instead of mixing the wort with the exhausted hops, the infusion should be drained from the hops and added to the wort in the underback. No loss of wort would thereby be sustained, and by putting the wet mass of hops in bags and subjecting them to pressure in a screw or hydraulic press, every particle of soluble bitter they could yield would be recovered.
Whether the plan of boiling or not boiling be followed, the wort is next transferred to the coolers, that its tempera- ture may be brought down sufficiently low to admit of its being fermented. The coolers are large flat cisterns or troughs, not in general more than six inches deep, extending the whole breadth of the building, and freely exposed to the air. These coolers are generally made of wood, but iron is very generally superseding wood, being found to possess many advantages. Slate, zinc, and latterly tiles, particularly Prosser's tilespathic tiles, have been also used. When the wort has been subjected to boiling, it generally reaches the coolers at a temperature of from 200° to 205°, and here it must cool down to the temperature of 54° or 60°. The more rapidly this can be effected the better, and hence the advantage of the coolers being in a free exposed situation, and hence also the use of fanners (or blowers), which many employ. When the wort is transferred at once to the mash-tun through the underback to the coolers, as by Tizard's plan, the temperature of the wort is only about 150°, so that the time occupied in cooling is greatly shortened. In summer brewing, the worts should always be ready to let into the coolers in the evening, to take advantage of the depression of temperature which occurs during the night. The coolers, if of wood, are recommended by some to be always kept covered with pure water till required, when this should be run off, and the worts run in. In this way, it is said, not only is the temperature of the coolers lower than it would otherwise be, but no waste of wort occurs as the pores of the wood are full of water; whereas, when this is not attended to, considerable loss of wort is experienced, not merely in watery parts which can be spared, but in saccharine extract. This practice, however, is condemned by many practical brewers who have tried the practice. They find they cannot have the coolers too dry when the wort is run on to them; dampness and wetness in the coolers tending much to produce that peculiar kind of disagreeable bitterness called "foxiness."
Many brewers condemn the use of fanners; others again consider them the most valuable aids. Those who object to them, do so on the principle that the current of air caused by the fanners keeps the wort in agitation, and prevents the deposition of those floccs or insoluble particles which fall from the wort as it cools. Those who use the fanners, again, assert that the gentle agitation of the surface does good to the wort, while it does not in the least interfere with the deposit of the sediment, which, indeed, may deposit in the coolers, but when the wort is run off, is almost all carried along with it into the fermenting tun. It must be apparent to any impartial observer, that as the sediment or floccs which fall are afterwards carried into the fermenting vat, it cannot be of the slightest importance to the eventual clearing of the beer, whether the wort on the coolers is agitated or be left still; consequently, if it be desirable to cool down the wort rapidly, the fanners can scarcely be dispensed with—more especially in close foggy weather, when stagnation of the air over the wort is a most fruitful cause of acidity.
During the process of cooling, the volume of the wort diminishes from one-eighth to one-fifth, owing to the evaporation, the effect of which is a concentration of the beer. As the cooling is effected almost entirely by evaporation from the surface, it takes place most rapidly during spring and autumn when the air is dry, and also when a current of air plays over the surface. In such circumstances, six or seven hours usually suffice to cool down the wort to the fermenting temperature, but if the air be moist, and there be no breeze, the cooling is sometimes so slow as to occupy twelve or fifteen hours. In such circumstances, the fanners, or blowers, are of inestimable value, as from the great extent of surface exposed the oxygen is absorbed, and the wort is apt to pass into the acetic fermentation.
Many refrigerators have been invented for the purpose of aiding the brewer to cool down his wort rapidly. In many breweries it is customary to cool down the wort only to 100° on the coolers, and then pass it through refrigerators in which it is brought in close contact with cold spring water, thus effecting a rapid reduction of temperature. Several patents have been taken out for different forms of these, but it does not appear that any of them have given such satisfaction as to lead to their general adoption; so that the coolers are still indispensable parts of the brewer's apparatus. It is an acknowledged fact that on the coolers a considerable loss of saccharine extract occurs, for if the strength of the wort be accurately gauged by the saccharometer before being passed to the coolers, and after it is run from them into the fermenting vat, it will be found that there is a considerable loss of saccharine matter not accounted for. This loss cannot be by evaporation. It seems to be simply loss of fluid on the surface of the coolers themselves; nor need this be wondered at, when we consider that even to wet the coolers it would require several barrels of water. The very fact of such a loss occurring should be an additional reason for the brewer adopting some simple refrigerator to cool down his whole wort, and not pass it into the coolers at all.
When the wort is sufficiently cooled down, it is run off into the fermenting vats, or "gyle tuns" as they are termed, where it is converted from the lascivious sweet wort, into the intoxicating beer. The gyle tuns are large square or cylindrical vessels of wood, varying in size according to the extent of the brewery. These vessels are never filled to the top, because a considerable head of yeast rises during the fermenting process, for which allowance must be made. It is of no small importance that the gyle tun should be placed in a chamber defended as much as may be from atmospheric vicissitudes, and the temperature ought to be maintained as uniformly as possible between 50° and 55°. The temperature to which the wort is cooled down depends on the rapidity with which the fermentation is to be conducted, and on the season of the year. The warmer the temperature of the air, the cooler should be the wort, lest the fermentation should rise too high. In England the wort is generally cooled down to 60° when the temperature is cold, but to 55° if the temperature is warm. In Scotland, again, the worts are if possible cooled down to from 50° to 53°, and the whole fermenting process is conducted more slowly. As a general rule, the cooler the worts are, when set to ferment, the slower but more regular will be the fermentation, and the more under our power to regulate.
When the wort is poured into the gyle tun, it is mixed with a certain quantity of yeast in order to set it into fermentation. In the large porter breweries, this yeast is in general previously mixed with a certain quantity of the wort a short while previous, and placed in a warm place to allow fermentation to commence in it. It is then styled "lobb." In the Scottish breweries the yeast is generally first mixed in the fermenting vat itself, with about six times its measure of wort, and then the whole wort is run from the coolers in full flow upon it. In England one gallon of yeast is generally sufficient to set in full fermentation 100 gallons of wort; but more is required in winter, and less in summer. In Scotland, where the fermenting process is conducted more slowly, and at a lower temperature, the proportion of yeast is one gallon to every four barrels during winter, and one gallon to every five barrels during spring or summer.
Yeast is the thick pasty fluid which separates from an infusion of malt when in a state of fermentation. When this is examined by the microscope, it is found to consist of globules of a greyish colour from the 3000th to the 4000th of an inch in diameter. When fermentation begins, these small corpuscular bodies move about in all directions, become larger, and small projections are seen to appear on their surface, which enlarge, drop off, and become independent corpuscles, and in their turn give birth to new ones. It is thus that during fermentation, a quantity of yeast is pro- Brewing.
Brewing, duced seven times as great as the yeast used. These glo- bules may be drained from the fluid in which they float when the yeast forms a mass like soft cheese; and in this state yeast used to be exported from Holland to France for the use of bakers, and is still so transmitted from one part of Germany to another, and has even been sent to India from Britain. From the experiments of Payen and Persoz, it appears that the essential operative constituent of yeast is a peculiar azotized matter, closely resembling albumen, gluten, caseine, &c., and is not sugar in a state of decomposition as was imagined by Dr Thomson. Hence they found that brain, white of egg, and many other nitrogenous substances, if mixed with a solution of sugar, caused it to ferment, and furnished a supply of yeast. These researches of Payen and Persoz strongly point out to the brewer the advantage of not destroying the albumen and gluten in the wort by boiling. Boiling, as already explained, destroys the greater portion of these principles, and throws them down in an insoluble state. But if the plan were adopted of running the wort from the mash-tun into the coolers, these valuable parts of the wort would be preserved, and would tend to render the process of fermentation surer and steadier.
The act of fermentation converts the sugar of the wort into carbonic acid gas (fixed air), which flies off, and alcohol (spirit of wine), which remains in the beer. This transformation or decomposition, "attenuation" as the brewers term it, is easily understood. Alcohol consists of 4 atoms of carbon, 6 of hydrogen, and 2 of oxygen, represented by $C_4H_6O_2$. Carbonic acid consists of 1 atom carbon, and 2 of oxygen; and as an atom of water is at the same time decomposed, we have 1 atom of grape sugar and 1 atom of water converted into 2 atoms of alcohol and 4 atoms of carbonic acid. Thus—
\[ \begin{align*} \text{Grape sugar} &= C_{12}H_{22}O_{11} \quad \text{form-} \\ \text{Water} &= H_2O \quad \text{ing.} \\ \end{align*} \]
Six or eight hours after adding the yeast, the fermentation becomes active. When this process is regular, a white creamy froth appears in the middle and round the edges of the fermenting vat, and gradually extends over the whole surface of the fluid. This frothy head increases more and more, being highest in the middle, and rises two or three feet above the surface of the fluid, gradually assuming a brown hue. During all this time there is a copious disengagement of carbonic acid gas, produced by the conversion of the sugar into alcohol and carbonic acid gas. At the same time, and keeping exact pace with this conversion, or "attenuation" as the brewers style it, the temperature of the fermenting fluid rises till it is 12° or 15° above that at which it was originally set; and an agreeable aroma or vinous smell (technically termed "stomach") is perceived. As this is the most important of all the stages, and it is very necessary the brewer should know whether all is going on regularly, we quote Mr William Black's excellent description of "a sound and regularly good fermentation."
"In such a fermentation five distinct changes occur, followed, after a certain stage, by a highly pungent aroma, which rises with the carbonic acid gas. If this aroma throughout the process be sound and vinous to the smell, we may feel assured that the worts are sound, and will go on regularly; if, on the contrary, a faintish, disagreeable, sub-acid flavour arise at any time during the process, we know that acidity or unsoundness has taken place, which should be corrected."
1. The first stage of fermentation commences with a fine white substance, like cream, appearing all round the edges of the gyle tun; this creamy appearance gradually extends over the surface of the fluid in the tun. This we call creamed over, or the first stage.
2. The next should be a curly appearance, like the head of a fine cauliflower, which should also extend all over the tun. This, the second change, we denominate the curling or cauliflower head. This cauliflower head should be examined very narrowly, as from its strong and healthy appearance or otherwise we may pretty nearly judge of the health of the gyle. As above stated, it should have the appearance of a fine cauliflower. If, however, it should assume the appearance of a well curled wig (we have no better phrase), having broad flaky curls, it denotes unsoundness. The aroma now should be very perceptible.
3. The curly head should then rise to a light yeasty or rocky head, little more than perhaps from two to three feet high, of a fine brownish white colour if sound. If unsound, it assumes in some parts an ugly bluish-white appearance, which often extends over the tun. This almost invariably happens where there is any galvanic action from chains of pipes or a mixture of metals; and cannot be cured or prevented but by doing away with the cause; that is by insulating the tunes.
4. After a time the light yeasty head should drop a little, perhaps only 4 inches. This we call the fourth change. The aroma should now be very vinous and pungent.
5. The light yeasty head which had dropped should now rise to what we call a close yeasty head, having the appearance of yeast all over, with many little air bubbles on the top, not, however, larger than a nut or walnut; these constantly breaking and others supplying their place. If the fermentation has been healthy throughout, the close yeasty head will continue rising and puffing out gas from the air-bells, until the beer is thought ready for cleansing. Should all these changes, as before stated, take place regularly, and be accomplished through the process by a sound healthy aroma (generally termed "stomach"), we may reasonably assume that all is right, and that the beer, if afterwards properly treated in storing, will turn out sound and good."
The time during which the fermentation is continued in the gyle tun varies according to the rapid or slow process of fermentation has been followed, also according to the state of the weather, the temperature of the wort, and other causes. When the quick process of fermentation is followed, as is usual in England, the wort is only kept fermenting in the gyle tun from 24 to 36 hours; and usually by the time the half of the saccharine extract is decomposed, and when the fermentation is still at its height, the yeasty head is beat down and mixed with the wort, when the whole is run off into fixed hogsheads, large barrels or "rounds," in order to be further fermented and "cleansed."
In Scotland, again, where the slow process of fermentation is commonly followed, the wort remains in the fermenting tun from six to twelve days, undergoing, during that period, a slower and more manageable fermentation than according to the English plan; and during this period the head of yeast is usually twice daily beat down, or mixed with the upper portion of the wort, till the proper degree of attenuation is attained. This is done with the view of re-exciting the activity of the fermentation.
The gyle tuns, or fermenting vats, are usually fitted with a coil of metal tubing for the purpose of regulating the heat of the wort, which may be raised or depressed by passing hot or cold water through them, as each may be required. Mr Black objects to the use of fixed metal tubing in the gyle tuns, as being liable to engender electrical currents, which interfere with the regularity of the fermentation. He therefore recommends a moveable regulator which can be let down into the fermenting vat by means of ropes and pulleys when wanted, fitted with pliable tubes attached to the metal regulator tubes, so that the flow of hot or cold water through them may be discharged over the side of the fermenting vat.
Mr Black has endeavoured to prove that electricity and electro-chemical agencies have much to do with many of the irregularities which are observed in wort during fermentation, and he has certainly pointed out a few marked instances where such a connection seemed to be established. He particularly objects to sinking fermenting vats in the earth, and relates an instructive instance relative to one so fixed, in which, on a day when a thunder-storm threatened, the fermentation became stationary, and all the usual means failed to forward the process; but on the wort being pumped out into casks supported on wooden rests, the fermentation spontaneously resumed, and was finished successfully. He therefore recommends all fermenting tuns to be supported Brewing on wooden pillars or beams, so as to isolate them as completely as possible. From this it is apparent that Mr Tizard's plan of having fermenting vats sunk in caves and underground excavations, and surrounded with water, whatever effect such might have in maintaining a uniformity of temperature, would be a sure means of making bad beer.
The next process in brewing is termed "cleansing." Properly speaking, this process is only required in the quick plan of fermentation; seeing that when the slow fermentation is followed no proper "cleansing" process is required.
It was mentioned above, that when the slow process was followed, as it is in Scotland, the fermentation was kept going on in the fermenting vat from six to twelve days. At the end of this period, the required degree of attenuation being attained, the head of yeast is no longer mixed with the wort, and a stream of cold water being passed through the refrigerators of the fermenting tun, the fermentation ceases, the temperature declines, the turbid particles separate, and by two or three days' rest, the beer becomes quite transparent. It has "cleansed" itself, and is now ready to be run off into the cask or store vat. When the beer or ale is run off from the gyle tun, all the yeast is left behind, both that which floated on the surface, and that which remained at the bottom. This retention of the yeast is accomplished by the crane in the bottom of the gyle tun being screwed up three-eighths of an inch above the level of the bottom. At one time it was the custom to allow the beer to settle in the fermenting tun for twenty-four or thirty-six hours, then run it off into a square of equal size with the fermenting vat, leaving behind in the vat the whole of the yeast. Here it was allowed to rest for a couple of days, after which it was found bright and ready for the cask. The Scottish brewers have very generally given up this plan, allowing their beer or ale to settle in the gyle tun itself, and run it off from it direct into the casks in which it is to be sent out. The beer undergoes no proper "cleansing" in these casks, that is to say, no further fermentation goes on in them, throwing up a quantity of yeast, but a couple of days is generally allowed to elapse before they are "shived" or bunged down.
In England, again, where the rapid plan of fermentation is adopted, "cleansing" is an essential part of the brewing process. As above mentioned, the wort is fermented to a certain extent only in the gyle tun, and as that fermentation is carried on at a higher temperature than in Scotland, it progresses more rapidly, attaining its maximum in from twenty-four to thirty-six hours. When it is thus at its height, the yeasty head is beaten down and mixed with the wort, and the whole is run off into large fixed barrels termed "cleansing rounds," whence it undergoes a farther stage of fermentation. In some breweries, before the wort is passed from the fermenting vat into these rounds, it is mixed with a certain quantity of wheat or bean flour, but this is a practice not generally approved of. In these vessels the yeast works over and escapes by a large aperture in the top of the barrel, to which a sloping wooden tray is fixed to convey the yeast into a trough. These rounds are usually placed in a double line, with the yeast trough between them, and by all communicating by means of pipes with a store vat at a higher level, are kept constantly full, fresh wort flowing in below in proportion as the yeast works over at the top. It is this process to which brewers have applied the term "cleansing," from the idea that the yeast working over and being removed from the beer "cleanses" it.
When the fermentation is ended in these rounds, the beer is run off into immense cylindrical vats or tuns, called "store vats," where an obscure sort of fermentation still goes on, increasing the strength of the beer, and keeping up a constant impregnation of carbonic acid gas, which renders the beer lively and agreeable to the taste when run off into casks for sale. These store vats are of immense size, usually capable of containing three thousand barrels of beer of 36 gallons each barrel, and weighing, when full, above five hundred tons. In these it was customary to keep immense stocks for eighteen months or two years until the beer "ripened," that is, lost most of its sweetness and mildness, and acquired a slightly acid taste, technically called "hardness." Good hard beer was then the favourite drink; but it appears that the taste of the consumers has changed now, and that mild beers are much more universally used. Hence in the great porter and ale establishments, it often happens that these liquors are consumed within six weeks of their manufacture.
In storing beer it is of great consequence that the temperature of the store room or cellar should be as uniform and as low as possible, seeing that increase of heat promotes fermentation, and is apt to cause the alcohol to become converted into vinegar. Underground cellars, where procurable, seem to fulfil these conditions better than others, and have therefore been strongly recommended. In consequence of electricity having such a marked effect on beer, particularly when kept in casks or store vats which communicate with or rest on the ground, it is desirable to have all these isolated as much as possible by resting them on wooden supports, at least eighteen inches above the surface of the ground, and not leaning on one another.
All beers, when well brewed and sound, after a certain repose become transparent, or "bright" as it is termed. When, however, beer is sent out very new, as is getting the custom, it is sometimes necessary to "fine" it, or impart to it that brilliant transparency which is so pleasing to the eye. This is done by means of "finings." The best finings for beer, indeed the only ones which should be used, are made of isinglass. This should be cut into shreds, put into a cask, and covered to the depth of 5 or 6 inches with vinegar or acid beer. When the isinglass has swelled up and absorbed all the vinegar or beer, it is covered to a like depth with a fresh quantity, and the whole vigorously stirred together. The same process of adding and stirring is repeated until the whole becomes of the consistence of a thick pulp or jelly. This jelly is then mixed with thin bright beer till it is brought to the proper consistence for use, when it is strained through a hair sieve which retains any undissolved portions of isinglass. The specific gravity of the finings should be about 1·025. From a pint to a quart of finings are used to clear a barrel of beer. The finings are first mixed up with some of the beer to be fined, then poured into the barrel and briskly stirred about. The cask is then bunged down for twenty-four hours, after which the beer should be found limpid. The action of the finings is to envelop all the floating feculencies, and carry them down to the bottom of the fluid. Various explanations have been attempted to account for this action, but Dr Ure's seems to be the most satisfactory. The fluid gelatine combines with the tannin of the hops, and thus forms a flocculent mass, which envelopes the muddy particles of the beer, and carries them with it to the bottom, where it forms a sediment. If a proper sediment does not fall, it may be made to appear by adding a little of the decoction of hops. If there be the slightest disengagement of carbonic acid gas, the flocculent particles, being thereby kept moving about, will not be enveloped in the finings, and the beer will not clear. This state is called "stubborn" by the brewers.
The above details will enable the reader to acquire a tolerably correct notion of the art of brewing, but as special drinks require somewhat special manipulations, we shall shortly notice these specialities under the heads Porter, English Ale, Pale Indian Ale, Home-brewed Ale, Scottish Ale, and Bavarian Beer.
Porter is a strong beer of a dark colour and peculiar flavour, and is said to be so named, either from its having been the common drink of the porters, or from Harwood, the original brewer of the drink, sending it round to his customers, Brewing by men, who when they knocked at the doors called out "porter," meaning thereby not the drink, but themselves, its porters or carriers. Porter was originally brewed to take the place of two or three kinds of beer which used to be mixed by the retailers in the mug as they drew them from the taps; and as this new drink had the taste of all three, but was brewed at once, and run out of one tap, it saved the publican trouble, and was denominated "entire." Hence, the sign so often noticed in London, such a brewer's "entire."
As provincial brewers have found it almost impossible to imitate the flavour and excellencies of the London Porter, various drugs have been used, or have been recommended to be used, in brewing this drink. Even some recent publications by practical men recommend burnt sugar and liquorice to give it colour, and copperas to give it a good head. Aloes, quassia, gentian, and even such poisonous ingredients as St Ignatius' bean and nux vomica, have at various times been recommended to be substituted for hops; and it is well known that paradise grains, notwithstanding the heavy penalty attached to their use, are still largely used surreptitiously in many parts of England to give greater sharpness to the porter and ale brewed there. It need scarcely be added, however, that such ingredients are never used by the respectable brewers, who use nothing but malt and hops, though some aid the colour by making use of burnt sugar or caramel.
As the dark colour of porter is that which more especially serves to distinguish it from other beers, we may describe the three colouring ingredients used for the purpose, promising that in general only one is used in the same brewing. 1. Black malt, or roasted malt, when used, is added in the proportion of from 3 to 5 bushels for every hundred bushels of malt; and is either mashed in the mash-tun along with the other malt, or is mashed separately, or is thrown into the wort when it is boiling. This malt, as before mentioned, yields no saccharine extract convertible into alcohol, but simply a dark-coloured mucilage, and is solely used for the purpose of giving colour and flavour. If this malt be added in too large proportion, especially if used with pale malt alone, it communicates a taste to porter which would be mistaken for that of liquorice, and this is probably the reason why liquorice is recommended to be used by the provincial brewer, and is often used by him for the purpose of imitating the London stout. 2. The second colouring ingredient is "essential bina." This consists of some of the first-drawn wort boiled down in an iron pan to the consistence of an extract, when it must be carefully and constantly stirred, and the heat continued till it has acquired a dark colour and peculiar flavour, in fact been converted into a caramel. Fifteen gallons of wort so boiled down usually suffice for from 20 to 30 barrels of wort, according to the depth of colour which is wished to be given. 3. The third colouring ingredient is "caramel" or burnt sugar. The process of preparing it is thus described. "Thirty pounds of raw sugar are put into an iron boiler which has a circular bottom, and dissolved in one gallon of boiling water over a moderate fire. It must be kept stirred, and attended with care. After boiling a few minutes, and being stirred with an iron scraper, it thickens, becomes dark coloured, and acquires a bitter taste. Care must be taken that it does not get scorched. It must be constantly stirred, and a small quantity of water added to keep it from setting to the bottom of the boiler. As soon as it approaches to inflame, it is ready to be removed, which is done by thinning it with boiling water, and delivering it to the boiling wort."
Porter is usually brewed from all the different kinds of malt, which are mixed in such proportions as shall suit the taste of the consumers. These proportions are different in different breweries. When black or patent malt is used as the sole colouring agent, Mr Tizard says that good porter may be made from mixtures of the different kinds of malt in the following proportions, the last being the best:
| No. | Black Malt | Brown Malt | Amber Malt | Pale Malt | Total | |-----|------------|------------|------------|----------|-------| | 1 | 3 | 25 | 15 | 57 | 100 | | 2 | 4 | 24 | 24 | 48 | 100 | | 3 | 5 | 0 | 95 | 0 | 100 |
When the colour is given with caramel or essential bina, the black malt is not used, and the colouring matter is added to the wort in the boiler.
It is unnecessary to repeat here the particulars relative to the mashing, boiling, cooling, fermenting, and cleansing of porter, seeing that these have been already fully detailed when describing the English plan of brewing. It may merely be mentioned that it is usual to cool down the wort to about 100° on the coolers, and then run it through refrigerators, or coils of pipes in contact with cold water, till the temperature is reduced to 60° in winter, or 55° in summer. It is then transferred to the gyle or fermenting tuns, which are in general fitted with a coil of metal tubing to give the power of regulating the temperature. The "lobbe" being added excites active fermentation, and in proportion as the saccharine matter becomes converted into alcohol, the temperature rises till it attains about 70 Fahr., beyond which it should never be permitted to get. If it threatens to rise beyond this, cold water should be passed through the refrigerators of the gyle tun, or the whole should be run off into the cleansing vats. This temperature is generally attained in from 30 to 36 hours; and as soon as the half of the saccharine extract has been converted into alcohol, which is generally within the 48 hours, it is run off into the rounds or cleansing vats. In the great London breweries these are of such a size as to contain from 10 to 20 barrels each; and as, during the process of "cleansing" from the yeast, the fermentation is still going on, the attenuation of the porter is wrought down to 5 or 7 lb. of saccharine extract per barrel. After this the porter is transferred to store vats, where in former days it used to be kept for 18 or 24 months in order to "ripen" or get "hard;" and as the brewer had thus to keep a two years' stock of porter on hand, the number and size of these in the larger establishments may be conceived. These store vats were usually made so large as to contain three thousand barrels of beer, each barrel being of the capacity of 36 gallons; and such a vat when full weighs about five hundred tons. In some of the largest breweries a few store vats existed of the enormous capacity of ten thousand barrels, and one monster vat was built in Whitehead's, which was said to be capable of containing twenty thousand barrels, or 720,000 gallons. It is not wonderful, therefore, that the bursting of one of these vats in Meux's brewery should have swept away a street, carrying the houses and all their inhabitants into the river. The changed taste of the public for mild malt liquors will soon probably make these immense store vats matters of history, as most of the malt liquor now used in London is reckoned old if kept in the brewery more than six weeks.
When porter is in the store vats, a low species of fermentation still goes on sufficient to reduce still further the proportion of saccharine extract, and furnish sufficient carbonic acid gas to impart to it an agreeable briskness. When porter is bottled the same changes go on—indeed it is questionable whether malt liquor is ever entirely quiescent.
The common draft London porter is made from a wort which is usually about the strength of 20 lb. of saccharine extract per barrel; the ordinary stout from wort of 25 or 26 lb. per barrel; and the strongest bottled stout, and porter for exportation from wort of 30 to 35 lb. per barrel. These different qualities are often stamped with the letters X, XX, and XXX; but this is a mere matter of convenience to the brewer; and porters from different breweries having the same stamp may be of very different strength. When porter is exported or sent to a distance, additional hops are added to it, varying in quantity in proportion to the distance it has to go. Export porter has usually about 4½ lb. of hops to each barrel. Strongest bottled porter has usually 8 lb. weight of hops to the quarter of malt; and common stout from 4½ to 6 lb. of hops per quarter of malt.
Porter has been analyzed for the purpose of ascertaining the proportion of alcohol contained in it. Mr Brande found 100 measures of brown stout to contain 6½ measures of rectified spirit of wine of the density of 825, equal to about 10½ per cent. of proof spirit, while common London porter yielded 4½ per cent. by measure of rectified spirit. Dr Christison, in 1838, found in bottled London porter 5¾ per cent. by weight of absolute alcohol, which is about 11½ per cent. by measure of proof spirit. From these experiments it appears, that London porter contains considerably less alcohol than the sour light wines of France or Germany, which yield from 15 to 19 per cent. of proof spirit.
Porter is an exceedingly wholesome and nutritious drink. Indeed, as a beverage, it cannot be denied that it is preferable to wine, however much some may vaunt the advantages which would result to this country from the duties on light wines being taken off, in order that they might come into more general use. As a beverage for the working classes, there can be no comparison between the sound, wholesome, and tonic beer of England, and the sour light wines drunk on the Continent. There is not a working man in England who would not despise and reject the acid wines used by the common people in the grape districts, even though they contain from 4 to 10 per cent. more proof spirit in them than his favourite beer; and, as to the finer qualities of light wines, they are produced in such small quantities that they cannot even now satisfy the wants of the upper classes, and no lowering of the duty would bring down their price to the working man's level.
Ale appears to be the most ancient drink of this country, and the name is usually given to strong beer of a pale colour, as porter is to that of a dark colour. The varieties of ale are infinite, but we purpose only to notice the peculiarity in the manufacture of English ale, Indian ale, English home-brewed ale, and Scottish ale.
In all high-priced English ales of the present day, brilliance and paleness of colour, with as little excess of sweetness as possible, are the objects to be attained by the brewer. To accomplish these ends, nothing but the finest pale malt must be used, and to secure sound-keeping ale, it is of first importance that the malt shall have been thoroughly dried on the kiln. If prepared from what is technically known as "slack-dried malt," that is malt not thoroughly dried for fear of colouring it, or which has had water sprinkled over it while still warm from the kiln, the worst as run from the mash-tun will be found acid, and will tinge litmus paper of a much deeper red than ordinary wort from well dried malt, and the ale prepared from it will not keep beyond a few months. It is necessary also to be careful in the selection of the hops for ale. Good sound hops should alone be used; many brewers now use a proportion of foreign hops along with the English hop.
In the brewing of common ale in England, it is customary to make three mashes, the first and second being fermented for ale, the last being reserved for beer. The heat of the water let on the first mash is usually 170°, that of the second 185°. The wort from these two mashes is mixed, and boiled for two and a half or three hours with hops, in the proportion of 8 lb. of hops to every quarter of malt. When the wort has cooled down to 60° or 65°, it is run off into the gyle tuns, and quick fermentation is excited by adding about one gallon of yeast for every barrel of wort. The fermentation in the gyle tun comes to maturity in about thirty-six hours, when the ale is run off into fixed barrels or rounds, where it undergoes a further fermentation, and is "cleansed" of its yeast, a hogshead of the ale being reserved for filling up the barrels as the yeast works over. In two days or so this process is over, when the ale is racked into barrels and removed into stock.
Since the public taste, relative to "hard beers," has changed, several of the great London brewers have turned their attention to the brewing of ale. They generally follow much the same plan as they did for porter brewing, following the quick process of fermentation, and finishing the attenuation in the rounds where the cleansing goes on. This mild ale has quite met the taste of the public, and seems to be gradually displacing porter. Ale is not, in general, attenuated so much as porter, or as the bitter ales intended for exportation; the attenuation of the ale is usually carried only to the decomposition of two-thirds of the saccharine extract.
Pale, Indian, or Burton Ale, originally intended for exportation, and now so deservedly in high repute as one of our most esteemed and wholesome beverages, requires more particular treatment in its manufacture. This ale can only be prepared from the best pale malt and the best hops; and the chief peculiarities attending its manufacture are, that it requires more than double the usual proportion of hops, that the attenuation is generally carried to a much greater extent, and that the temperature during the fermentation should never be allowed to exceed 65° Fahr. That a considerable amount of sweetness should exist in common ale is allowable, and indeed, it is the presence of a large quantity of undecomposed saccharine extract which gives to common strong ale its luscious mildness. It is, however, the presence of this large quantity of undecomposed saccharine extract which prevents common ale from being used as a diet drink by the invalid, or being relished in a warm country; and it is the circumstance of the Indian or pale ale having its fermentation carried so much further, and its saccharine matter reduced in quantity, together with its larger proportion of bitter, that commends it so much as a grateful and stimulant stomachic to the European resident in a warm climate, and to the invalid.
The manufacture of this beverage has been endeavoured to be shrouded in much mystery; but we have ascertained that pale bitter ale of first rate quality may be brewed by following with care any of the ordinary plans of fermentation, either the ordinary quick English system, or the slower Scotch process. It has appeared to us, however, that the best keeping, the highest flavoured, and the least acid ale, was always prepared by the slower process, in which the temperature is never raised so high as in the quick process of fermentation. The quantity of hops found necessary for Indian ale is from 18 to 22 lb. per quarter of malt; and the ordinary strength of the wort, when passed into the gyle tun, is 24 lb. per barrel, or 1086 of specific gravity. This gives, with good malt, about four barrels of pale ale for every quarter of malt.
When the slow plan of fermentation is followed in England, it is recommended that the pitching temperature should not exceed 65°, and the gyle tun, in every case, must be fitted with refrigerator tubes to regulate the temperature of the wort. Some brewers consider it of essential importance to keep down the heat of the wort during the early stage of the fermentation, and so to regulate the temperature by a stream of cold water through the refrigerator tubes of the fermenting tun, that at the expiration of forty-eight hours the temperature shall not have increased 3° above the pitching heat, by which time the saccharometer indicates an attenuation of 7 or 8 lb. It is, of course, necessary to visit the fermenting vat every fourth or fifth hour day and night. By the time the temperature has risen to 62°, the half of the original strength of the wort should be found to be attenuated. In this plan of fermentation the temperature is allowed slowly to rise to 64°, by which time three-fourths of the saccharine extract should be attenuated, and at this stage half of the yeasty head is recommended to be skimmed off. When 2 lb. more of the saccharine extract have been decomposed, one-half of the yeasty head is again skimmed off. The density, by this time, should be reduced to 6 lb. per barrel, but the attenuation has still to be carried on till 4 lb. of saccharine extract remain undecomposed. If the fermentation therefore gets languid, the yeasty head should be beaten in. When the desired attenuation is attained, that is when the wort, or ale rather, is reduced to about 4 lb. of extract per barrel, or to the specific gravity of 1011 or 1012, the whole head of yeast is carefully skimmed off, and cold water is passed through the refrigerator tubes, so as to cool down the ale as quickly as possible, and arrest further fermentation. As the fluid comes to rest, by the cooling arresting further fermentation, all impurities subside, and in a few days the ale is pure and transparent, its temperature has fallen to 50°, and it is fit to be drawn off into the store vat. By this process the wort is kept in a state of unnecessarily slow fermentation for twelve or thirteen days.
Other brewers, therefore, who also follow the slow plan of fermentation, instead of retarding the rise of heat during the early stage of the fermentation, allow and encourage it to rise as rapidly as possible to 62°, and maintain it steadily at that temperature, and never allow it to exceed that heat till the required degree of attenuation is attained. Instead of skimming off the yeasty head, these brewers twice daily lightly beat in the head, which hastens the attenuation, so that in general, by the sixth or seventh, and never exceeding the eighth day, the required attenuation is attained. A full stream of cold water is then sent through the refrigeratory tubes of the fermenting vat. The yeasty head is left untouched, and the ale is either allowed to rest in the fermenting tun for two or three days, by which time it becomes pure and transparent, and its temperature falls to 50°, when it is drawn off into casks or into the store vat; or, after a rest of twenty-four hours, it is transferred to a vessel of similar size with the fermenting tun, leaving behind it all the yeast, where it is allowed to rest for a couple of days before being stored or drawn off into casks. After being drawn off into casks it is generally allowed to stand for a couple of days before being shived down, and a handful of fresh hops is added to each cask.
When the water used for brewing pale ale is hard, some brewers assert, and act on the principle, that the pitching heat must be higher, and that the fermentation must be conducted on the quick plan. Some of the largest Burton brewers accordingly manufacture their pale Indian ale by the rapid fermentation process, and boast that they "have brewed and shipped their ales to India in the course of a few days." Whatever may be thought of the practice, the reasoning is bad, seeing that it has been found that the hard water used by the Burton and other brewers loses all its hardness in the mash-tun, and by the time it reaches the fermenting vat is as soft as if the softest river water had been used.
When the rapid plan of fermentation is followed, the pitching heat is set at 60° Fahr.; and the quantity of yeast employed, though varying according to the season, is about 1 gallon for every 2 barrels of wort. Vigorous fermentation is thus excited, and in from 24 to 30 hours the wort should be found to be attenuated one-half, while, by means of the refrigerator tubes of the fermenting vat, the heat should not be allowed to rise higher than 7° above the pitching heat. It is often, however, extremely difficult to keep down the temperature within these limits even with a full flow of cold water through the refrigerators; and if it be allowed to rise to 70° the ale is extremely liable to get acid within a few months, even in this country, and is almost sure to do so if exported to an Indian climate. As soon, therefore, as the above attenuation is obtained, or the heat threatens to rise higher than 7° above the pitching heat, the whole is run off into fixed hogsheads or rounds, where the attenuation is carried to the desired extent, and the ale is "cleansed." Several brewers who manufacture largely for the foreign market assert that no pale ale can be trusted for exportation whose heat in the gyle tun has exceeded 65°, and in practice they never allow it to exceed 65°. They attribute the large losses which some houses have sustained from ale spoiling in India to this cause; and in their own experience they have never found one cask of ale go wrong whose heat during fermentation was kept below 63° Fahr. When the ale is racked off into casks a handful of hops is added to each to insure its keeping qualities.
Pale Indian ale, if properly brewed, never requires fining,—it clears of itself; and if not clear, it is very rarely indeed that finings will restore to it its crystalline transparency.
The small quantity of undecomposed or unattenuated saccharine extract left in this kind of ale is sufficient, by its slow and gradual fermentation, to supply enough of carbonic acid gas to induce a pleasant liveliness without inducing the slightest turbidity; and the large quantity of bitter in it enables it to bear the heats of India, where it constitutes one of the most refreshing and invigorating of beverages.
The reputation which this bitter ale has acquired, and the demand for it in India, our colonies, and in this country, have induced many brewers over the kingdom to direct their attention to its manufacture; and the consequence has been that numerous brewers now manufacture a pale bitter ale quite equal to the best of either Bass or of Allsopp.
Many, however, who now manufacture an excellent pale ale for the foreign market, do not carry the attenuation so far as above described, but arrest the fermentation when the specific gravity of the wort or ale arrives at 1018; in other words, they only carry the attenuation to the decomposition of nearly three-fourths of the saccharine extract,—the original gravity of the worts of these ales ranging from 1066 to 1068. These pale ales are brewed by the slow fermentation process, the fermentation lasting six or seven days. It would appear that ale with even this considerable amount of undecomposed saccharine extract bears well the heat of a warm climate; these brewers having never yet lost a single cask by their ale souring or otherwise going wrong.
From these statements it will be apparent that pale bitter ale, as at present manufactured, is not brewed according to one fixed plan; but may be brought to perfection either by the quick or the slow process of fermentation, and either by carrying the attenuation to the decomposition of nine-tenths of the saccharine extract, or only to the decomposition of three-fourths.
We believe that good and sound ale may be brewed by any of these processes; but it cannot be denied that when the rapid fermentation is followed the tendency to acidity must be much greater than in slowly fermented ale. This difference may not be so strongly manifested if the ale be used in this country, but, if sent to India or other warm climate, such rapidly fermented ale runs a much greater chance of becoming sour. This is entirely attributable to the higher temperature which the rapidly fermented ale attains in the fermenting vat, and which every now and then it is found almost impossible to check. It is very questionable, indeed, whether any ale, or other malt liquor, whose heat has been raised in the fermenting vat to 70°, will bear unchanged the heat of an Indian climate. The reason of this is very apparent. At the temperature of 70° there is a much stronger tendency in the liquor to undergo the acetous (vinegar) than the alcoholic fermentation. Indeed, the surest way to induce the acetous fermentation is to raise the temperature of the fermenting liquor above 70°, and acetic acid is rapidly produced, as is well known to and acted on by the vinegar manufacturers. Any near approach to this temperature should therefore be carefully avoided in the manufacture of malt liquors.
Mr Roberts has published a table of analysis of 40 specimens of pale Indian ale. He found the average specific gravity of these, taken from cask and bottle, to be 1007-26. If we take only the 15 samples taken from the cask, the average specific gravity was 1008-25, or, in brewers' language, nearly 3 lb. of saccharine extract per barrel. This, then, shows the average attenuation of the Indian ale at present in the market, but does not with any certainty show the extent to which the attenuation of the wort was carried by the brewer. It was before remarked that the attenuation of malt liquors goes on both in the cask and in the bottle; so that, unless we know the date at which the ale was brewed, and allowed for this, we might make sad mistakes as to the extent to which the attenuation had been carried by the brewer. Thus we lately examined an ale which was attenuated by the brewer only to 1018 of specific gravity, but after having stood six months in bottle the specific gravity was found reduced to 1012.
Mr Roberts' tables show also the quantity of proof-spirit contained in these pale bitter ales. The 40 ales he examined yielded on an average 11-59 per cent. of proof-spirit; the highest examined yielding 13-65 per cent., and the lowest 8-82 per cent. of proof-spirit. Pale Indian ale, therefore, contains a third less of spirit than the sour vin du pays and other light and acid Continental wines; while its freedom from acidity, its gently stimulant action, and its tonic qualities, constitute it a beverage as superior to these wines as one drink can be to another.
Home-brewed Ale, as brewed by the middle classes in England, is usually made in quantities of 2 barrels, i.e., 72 gallons. For this purpose a quarter of malt, or if wished to be extra strong, 9 bushels of malt are taken, with 12 lb. of hops. The malt being crushed or ground, is mashed with 72 gallons of water, at the temperature of 160°, and covered up for three hours, when 40 gallons are drawn off; and into this the 12 lb. of hops are put and left to infuse. Sixty gallons of water at the temperature of 170° are then added to the malt in the mash-tub and well mixed, and after standing two hours 60 gallons are drawn off. The wort from these two mashes is boiled along with the hops for two hours, and after being cooled down to 65°, it is strained through a funnel bag into the fermenting tub, where it is mixed with one-and-a-quarter gallons of yeast, and left to work for twenty-four or thirty-six hours. It is then run into barrels to cleanse, a few gallons being reserved for filling up the casks as the yeast works over. Eighteen or twenty gallons of beer are obtained from the used malt by making a third mash with twenty-five or thirty gallons of water, and boiling the wort thus procured with the used hops.
Scottish Ale, but especially the Edinburgh ale, has been long celebrated, but as an ordinary beverage, it is much more luscious and heady than London porter, English ale, or pale Indian ale. It is a much stronger drink than any of these, the home-brewed English ale approaching nearest to it in this respect; and as the attenuation of the saccharine extract is only carried the length of the decomposition of two-thirds of its original strength, the large quantity of undecomposed saccharine extract renders it much more luscious to the taste, and milder than the English ales. The Scottish ales are brewed of various strengths, and are known in the market by their price per hogshead, and are hence commonly mentioned as L.7 ale, L.5 ale, &c. According to the kind of ale required the worts are prepared of various degrees of gravity as indicated by Allan's saccharometer. Speaking in a general way, L.3 ale has a wort of the specific gravity of from 1070 to 1080; L.4 ale wort from 1080 to 1095; L.5 ale wort from 1095 to 1110; L.6 ale wort from 1110 to 1120; and L.7 ale wort from 1120 to 1130.
By the Scottish plan only one mash is made, using for the stronger ales about 1½ barrels of water to each quarter of malt. The whole water is run in at once into the mash-tun at the temperature of 180°, and the crushed malt, as it is poured into the water, is thoroughly mixed with it by means of ears and rakes, and all the lumps carefully broken. The mash-tun is then covered over and allowed to stand for three hours. The heat of the mash-tun at the surface is usually about 140°, but the heat in the interior of the mash is higher, seeing the wort when run off has usually a temperature of about 155°. At the end of this period the sparger, formerly described, is fixed to the mash-tun, and the taps being opened the wort is permitted to flow out, at first slowly till it runs clear, afterwards at full tap. The sparger is then set in motion, and sprinkles the surface of the mash with as much hot water, at the temperature of 180° or 185°, as flows out from the tap below. The surface of the mash is thus kept from becoming dry, else the whole mash would fall into cracks, and also separate from the sides of the mash tun, and allow the water to escape without carrying with it the saccharine extract.
Supposing that a L.4 ale were wished, and a small brewing were made of 8 quarters of malt, 30 barrels of wort would be run off at the specific gravity of 1072. The wort being pumped into the boiler, after boiling half an hour would have 40 lbs. of hops added to it, and in another half hour other 40 lbs., making in all 80 lbs. of hops. For the higher priced ales 10 lbs. of hops per quarter of malt are occasionally used. The boiling of the wort is continued from an hour to an hour and half longer, until the gravity of the wort is increased to 1084, when it is passed to the coolers, where it is still further strengthened by evaporation, so that when pitched in the gyle tun its gravity is about 1092, and its bulk reduced to 23 or 24 barrels. The wort being cooled down to 50° or 52°, six gallons of yeast, or more or less according to the season, are mixed in the gyle tun with a barrel of the wort, when the rest of the wort is let run into the gyle tun from the coolers in full stream, and the whole is well mixed. The process of fermentation occupies from ten to twelve days, and the heat during the fermentation is never allowed to rise higher than 62°, or 10° above that at which it was pitched, and the yeasty head is repeatedly beat down, usually twice daily, during that period. When the brewer finds that the attenuation has been carried so far as to reduce the specific gravity to 1031, in other words, that two-thirds of the saccharine extract have been converted into alcohol, the ale is left undisturbed in the fermenting vat for 2 or 3 days, by which time it has become clear and transparent, all fermentation has ceased, and its temperature has fallen to 50° or 52°. It is then run off into the casks in which it is to be sent out, which are allowed to stand a couple of days before being bunged down. Finings are scarcely ever required for these ales.
These heavy ales are being gradually displaced by the more wholesome, lighter, and more thoroughly fermented bitter ales of which the Indian ale is the type.
These Scotch ales contain a large percentage of alcohol. Mr Roberts has published a table containing the analysis of 71 samples of different Scotch ales, and found they contained on an average of the 71 ales 14-59 per cent. of proof spirit. The higher priced ales, as those at L.6 and L.7, contained 16 and 17 per cent. of proof spirit, the highest sample containing 185 per cent. The low priced ales, as those of L.3 and L.4, contained on the average 11 and 12 per cent. of proof spirit; the lowest sample of L.2 ale contained 9-8 per cent. of spirit.
The following table shows the quantity of beer or ale exported from Great Britain and Ireland during the years ending 5th January:— Bavarian Beer is the only other malt liquor which, from the peculiarities attending its fermentation, requires a special notice. The Germans, from the earliest historical periods, have been a beer-drinking nation, and some excellent malt liquors are made in that country. The "weiss bier," the truly patriotic beverage of Prussia, is not made from barley alone, but from 1 part barley malt and 5 parts wheat malt; but the excessive tendency of wheat beers to sour has caused potato starch to be substituted for the wheat, and tartaric acid to give the admired tartness. The other beers, however, more especially the ones now to be noticed, the Bavarian beers, both the common pot beer (schank-bier) and the intoxicating lascivious bock-beer, are brewed from barley malt alone.
The peculiarities attending the manufacture of these beers attracted little notice in this country till the publication of Liebig's Chemistry in its application to Agriculture and Physiology in 1840 directed attention to the subject by contrasting the keeping qualities of the Bavarian beer with that of the English and French beers. Dr Ure has since then personally examined these beers and their mode of manufacture, but did not find the vaunted qualities of the German bier so uniform as Liebig would have us believe. "This perfection (says he) is, however, in my opinion, rarely attained. In my several journeys into Germany I have met with much spurious or ill-made Bavarian beer. The best contains, when brought to England, a little acid." — Dictionary of Arts, &c., vol. i. p. 156.
Liebig's being still the best description of the chemical changes which accompany the peculiar mode of fermentation adopted for Bavarian beer, we give it entire from the work above quoted, without, however, subscribing to his views, which are fanciful in some points, and in others scarcely in accordance with known facts.
"English, French, and most of the German beers, says Liebig, are converted into vinegar when exposed to the action of air. But this property is not possessed by Bavarian beer, which may be kept in vessels only half filled without acidifying or experiencing any change. This valuable quality is obtained for it by a peculiar management of the fermentation of the wort. The perfection of experimental knowledge may have led to the solution of one of the most beautiful problems of the theory of fermentation.
"The wort is proportionally richer in gluten than in sugar, so that during its fermentation in the common way a great quantity of yeast is formed as a thick foam. The carbonic acid evolved during the process attaches itself to the particles of the gluten, by which they become specifically lighter than the liquid in which they are formed, and rise to the surface. Gluten, in the act of oxidation, comes in contact with the particles of the decomposing sugar in the interior of the liquid. The carbonic acid from the sugar and insoluble ferment from the gluten are disengaged simultaneously, and adhere together.
"A great quantity of gluten remains dissolved in the fermented liquid, even after the transformation of the sugar is completed, and this gluten prevents the conversion of the alcohol into acetic acid, on account of its strong attraction for free oxygen and its undergo decay. Now it is plain, that with its separation, and that of all substances capable of attracting oxygen, the beer would lose the property of becoming acid. This end is completely attained in the process of fermentation adopted in Bavaria.
"The wort, after having been treated with hops in the usual manner, is thrown into very wide flat vessels, in which a large surface of the liquid is exposed to the air. The fermentation is then allowed to proceed, while the temperature of the chambers in which the vessels are placed is never allowed to rise above from 45° to 50° Fahrenheit. The fermentation lasts from three to six weeks, and the carbonic acid evolved during its continuance is not in large bubbles which burst upon the surface of the liquid, but in small bubbles, those which rise from a liquid saturated with high pressure. The surface of the wort is scarcely covered with a scum, and all the yeast is deposited on the bottom of the vessel in the form of a viscous sediment.
"In order to obtain a clear conception of the great difference between the two kinds of fermentation, it may perhaps be sufficient to recall to mind the fact that the transformation of gluten or other azotized matters is a process consisting of several stages. The first stage is the conversion of the gluten into insoluble ferment in the interior of the liquid, and as the transformation of the sugar goes on at the same time, carbonic acid and yeast are simultaneously disengaged. It is known with certainty that this formation of yeast depends upon oxygen being appropriated by the gluten in the act of decomposition; but it has not been sufficiently shown whether this oxygen is derived from the sugar, or from the gluten itself; whether it combines directly with the gluten or merely with its hydrogen, so as to form water. For the purpose of obtaining a definite idea of the process, we may designate the first change as the stage of oxidation. This oxidation of the gluten, then, and the transposition of the atoms of the sugar into alcohol and carbonic acid are necessarily attendant on each other, so that if one is arrested the other must also cease.
"Now, the yeast which rises to the surface of the liquid is not the product of a complete decomposition, but is oxidized gluten still capable of undergoing a new transformation by the transposition of its constituent elements. By virtue of this condition it has the power to excite fermentation in a solution of sugar; and if the gluten be also present, the decomposing sugar induces its conversion into fresh yeast, so that in a certain sense the yeast appears to reproduce itself.
"Yeast of this kind is oxidized gluten in a state of putrefaction, and by virtue of this state it induces a similar transformation in the elements of the sugar.
"The yeast formed during the fermentation of the Bavarian beer is oxidized gluten in a state of decay. The process of decomposition which its constituents are suffering gives rise to a very putrefactive putrefaction (fermentation) in the sugar. The intensity of this action is diminished in a great degree, that is, the gluten which the fluid holds in solution takes no part in it; the sugar in fermentation does not excite a similar state in the gluten.
"But the contact of the already decaying and precipitated gluten or yeast causes the emacausis (decay) of the gluten dissolved in the wort; oxygen gas is absorbed from the air, and all the gluten in solution is deposited as yeast.
"The ordinary frothy yeast may be removed from fermenting beer by filtration without the fermentation being thereby arrested; but precipitated yeast of Bavarian beer cannot be removed without the whole process of its fermentation being interrupted. The beer ceases to ferment altogether, or if the temperature be raised considerably, fermentation takes place, but precipitated yeast does not excite ordinary fermentation, and consequently is quite unfit for the purpose of baking; but the common frothy yeast can cause the kind of fermentation by which the former kind of yeast is produced.
"When common yeast is added to wort at a temperature of between 40° and 50° Fahrenheit, a slow tranquil fermentation takes place, and a matter is deposited on the bottom of the vessel which may be employed to excite new fermentation; and when the same operation is repeated several times in succession, the ordinary fermentation changes into that process by which only precipitated yeast is formed. The yeast now deposited has lost the property of exciting ordinary fermentation, but it produces the other process even at a temperature of 50° Fahrenheit. In wort subjected to fermentation at a low temperature, with this kind of yeast, the conditions necessary for the transformation of the sugar is the presence of that yeast; but for the conversion of gluten into ferment by a process of oxidation, something more is required.
"When the power of gluten to attract oxygen is increased by contact with precipitated yeast in a state of decay, the unrestrained action of air is the only other condition necessary for its own conversion into the same state of decay, that is, for its oxidation. We have already seen that the presence of free oxygen and gluten are conditions which determine the emacausis of alcohol, and its conversion into acetic acid; but they are incapable of exerting this influence at low temperatures. A low temperature retards the slow combination of alcohol, while the gluten combines spontaneously with the oxygen of the air, just as sulphurous acid does when dissolved in water. Alcohol undergoes no such changes at low temperatures; but during the oxidation of the gluten in contact with it, is placed in the same condition as the gluten itself when sulphuric acid is added to the wine in which it is contained. The oxygen of the air unites both with the gluten and alcohol of wine, not with sulphurous acid; but when the acid is present it combines with neither of them, being altogether absorbed by the acid. The same thing happens in the peculiar process of fermentation adopted in Bavaria, the absence of oxygen prevents its combination with the gluten and not with the alcohol, although it would have combined with both at higher temperatures, so as to form acetic acid.
"Thus, then, this remarkable process of fermentation with the precipitation of a mucous-like ferment, consists of a simultaneous..." Brewing, putrefaction and decay in the same liquid. The sugar is in the state of putrefaction, and the gluten in state of decay. In the fermentation of beer after sugar, all the substances which cause decay are removed from it by means of an unrestrained access of air, while the temperature is kept sufficiently low to prevent the alcohol from combining with oxygen. The removal of these substances diminishes the tendency of the beer to become acetic, or, in other words, to suffer a further transformation."
Notwithstanding Liebig's praise of the Bavarian beer, much of it, as commonly brewed, is an inferior drink. Even its keeping qualities have been greatly over-rated. In the Grand Duchy of Hesse a considerable premium was offered for the preparation of beer according to the Bavarian method; and the premium was to be adjudged to any one who could prove that the beer brewed by him had lain for six months in the store vats without becoming acid; but we are informed that hundreds of casks of beer were lost in the endeavour to fulfill the conditions.
It would appear that, as in the case of the Indian ales, Bavarian beer can be well brewed by a much more rapid process of fermentation than one extending over "three to six weeks." Dr Ure, in describing the process followed in Bavaria, mentions that the pitching heat of the wort for the ordinary schank-bier is from 54° to 59°, and, as might be expected at these heats, the wort undergoes a nearly ordinary fermentation, even though the deposit-yeast be used, yeast rising to the surface and forming a tolerable head; and in five or six days the beer is ready to be transferred to the store tun. For the best keeping beer, however, the wort is pitched at the temperature of 41° to 43°, and the fermenting process is consequently much slower: no head of yeast is formed, all is deposited. From this it would appear that the low pitching heat has more to do with the production of deposit-yeast and the non-production of head-yeast than any other requisite. This statement also enables us to understand how so much of the Bavarian beer should be of bad quality, much of it being virtually ill-brewed ordinary beer.
Excellent Bavarian beer has been brewed in Edinburgh. Messrs James Muir and Sons, more than twenty years ago (1832), procured from Bavaria a supply of the deposit-yeast, and with it made several brewings of beer. It was found that good beers could only be brewed with this yeast if the wort was of low specific gravity. The worts were pitched at the temperature of 45°, in the ordinary gyle tun, and were never allowed to rise above 48°. A slight cream or scum at first appeared on the surface; the whole yeast was deposited at the bottom, and the brewing was completed in 10 or 12 days. Better beer was never turned out of any brewery, and they could not supply the demand for it. The supply of deposit-yeast was kept up for many months, when on using a stronger wort, and the weather not permitting the wort to be cooled sufficiently, ordinary fermentation took place, and the supply of deposit-yeast was destroyed. The manufacture of this beer, interfering with their ordinary trade, was not resumed; but their opinion is, that the process is excellently adapted for the manufacture of all the light beers, and as it requires no change in the ordinary apparatus, it is worthy the attention of the table beer brewers. In Bavaria, when the ordinary deposit-yeast cannot be procured, the common yeast which is deposited in every fermentation—which indeed seems to be identically the same—is carefully separated from the head-yeast, and used; and after one or two brewings is found to be of sufficient purity for the finest beers. The sole inconvenience attending the Bavarian process is, that it can only be carried on during the six coldest months of the year.
A few years ago the legislature permitted the Board of Excise to grant leave to use sugar in place of barley malt in breweries. Dr Ure was employed by an extensive sugar merchant to make experiments for the purpose of ascertaining whether sugar could be economically substituted for malt. He examined 10 samples of Muscovado sugar, and found the average yield was 12 gallons of proof spirit for every 112 lbs. of sugar; whereas an equal quantity of proof spirit could be obtained from 4½ bushels of malt. One pound of malt he found yielded ¾ lb. of extract, capable of making as much spirit as that weight of sugar. By contrasting the price of sugar and malt, any one can see that sugar cannot be used economically in the brewery. Several extensive brewers however, were induced to try the experiment on the large scale, as for instance the Messrs Whitbread & Co., who in 1847 used no less than 627,188 pounds weight of sugar in their brewery; but almost all seem now convinced, not only that it is not economical, but that it makes an inferior beer to malt.
But, though unprofitable to use sugar alone in brewing beers, some brewers have found it highly advantageous to use it as an auxiliary to the malt. The proportion of sugar which it has been found profitable thus to employ varies from a sixth to a fourth of the estimated quantity of saccharine extract of malt in the wort; and the sugar is added to the wort either when it is boiling in the copper, or when it is passed into the fermenting vat. In the latter case it must be previously dissolved in water, so as to reduce it to the state of a syrup. It has also been recommended to add sugar in the form of a syrup to export beers, especially to those which have become thin in body from the fermentation having been carried too far, as is sometimes the case in spite of all efforts to prevent it when the quick English plan of fermentation is adopted. The addition of a small quantity of strong syrup, highly hopped, is said to improve such beer, not only restoring to it that fulness of body which it had lost, but enabling it to stand exportation much better than it would otherwise do.
Before concluding this article, we must notice a simple mode of analysis for beers, by means of which three useful facts may be arrived at, viz., the original gravity of the wort, the degree of attenuation of the saccharine matter, and the proportion of proof spirit in the beer. The instruments required for this purpose are: 1st, A saccharometer or hydrometer. 2d, A glass sample tube large enough to hold 4 ounces of fluid, and deep enough to allow the hydrometer to be used. 3d, A four-ounce glass bottle furnished with a glass stopper, having a hole drilled through its centre. 4th, A thin glass flask of twice the capacity of the measure bottle, or a retort with its condenser.
The mode of analysis now to be described, appears to have been first suggested in this country by Mr Stevenson of Edinburgh, to have been further investigated by Messrs Dobson and Phillips of the Inland Revenue Department; and, lastly, by a commission appointed by the Board of Inland Revenue, consisting of Professors Graham, Hofmann, and Redwood. The object of these investigations was to enable the excise to estimate more correctly the original gravity of the wort of export ales, for the sake of paying the drawback which is allowed on beers of a certain strength. By the act of 10th Victoria, cap. 5, a drawback is granted of "five shillings per barrel of 36 gallons upon beer exported, of which the worts used before fermentation are of not less specific gravity than 1054, and not greater than 1081; and a drawback of seven shillings and sixpence upon beer exported, of which the worts used before fermentation are of not less specific gravity than 1081." There are two modes of making this analysis, the first that suggested by Mr Stevenson, the second that improved upon by the above professors and adopted by the excise. The first may be styled the "evaporation process," the second the "distillation process."
1. The Evaporation Process.—The beer to be examined is to be poured into the sample tube, and allowed to stand till all the carbonic acid gas has escaped. It is then brought to the temperature of 60°, and its specific gravity is taken
Brewing, by means of the saccharometer and marked down. Let us suppose we find it 1024. The four-ounce measure bottle is then filled with the beer, and the stopper inserted; the surplus beer escapes through the drilled hole, leaving the bottle quite full. This measured quantity of beer is then poured into the glass flask, the bottle carefully washed out with water, and the rinsings added to the flask. The flask is then placed over an argand or gas burner, and boiled till rather more than half of the beer is evaporated. The heat drives off all the alcohol. The inspissated beer or extract is then poured back into the measure bottle, the flask washed out with pure water and the washings also added to the bottle, and the bottle then filled up to its original measure with pure water. The specific gravity of this mixed fluid is then taken in the test tube, and as water has now taken the place of spirit, its gravity is found to have increased to 1036, or an increase of gravity of 12 degrees. These 12 degrees are styled the "spirit indication," from indicating the percentage of proof spirit in the beer. This then gives an answer to one of our queries, viz., the proportion of proof spirit in the beer.
We wish, however, to find out the original gravity of the wort. To get at this we must refer to the excise tables of spirit indications. By these we learn that the 12 degrees, the "spirit indication" of this beer, requires a wort of the specific gravity of 543 to produce it. To get the original gravity of the wort, however, we must add the ascertained gravity of the extract, ascertained as above to be 36, which added to the 543 gives 10903 as the original specific gravity of the wort before the beer was manufactured.
The researches of Professors Graham, Hofmann, and Redwood, show that this mode under-estimates the proportion of spirit in the beer, and, of course, the strength of the wort. They therefore recommend, and the excise have adopted,
| Degrees of Spirit Indication | 0 | -1 | -2 | -3 | -4 | -5 | -6 | -7 | -8 | -9 | |-----------------------------|---|----|----|----|----|----|----|----|----|----| | Spirit indication ...........| 56·9| 54·3| | Extract gravity ............| 36 | 36 | | Original gravity of wort ...| 92·9| 90·3|
We subjoin the table constructed by Professors Graham, Hofmann, and Redwood, by which in future the Inland Revenue will be guided in giving back the drawback on all export beers; the numbers in the body of the table indicate the strength of wort corresponding to the spirit indications marked on the margin.
EXPLANATION OF THE PLATES.
Figs. 1 and 2, Plate CXLII., explain the arrangement of the utensils and machinery in a porter brewery on the largest scale; in which, however, it must be observed that the elevation, fig. 1, is in a great degree imaginary as to the plane upon which it is taken; but the different vessels are arranged so as to explain their uses most readily, and at the same time to preserve, as nearly as possible, the relative positions which are usually assigned to each in works of this nature.
The malt for the service of the brewery is stored in vast granaries or malt-lofts, usually situated in the upper part of the buildings. Of these, we have only been able to represent one at A, fig. 1; the others, which are supposed to be on each side of it, cannot be seen in this view. Immediately beneath the granary A is the mill, in the upper floor of which are two pair of rollers for bruising or crushing the grains of the malt. (An enlarged representation of the rollers is given at figs. 3 and 4.) In the floor beneath the rollers are the mill-stones b b, where the malt is sometimes ground, instead of the simple bruising which it receives by passing between the rollers.
The malt, when prepared, is conveyed by a trough into a chest d, from which it can be elevated by the action of a spiral screw e (see also figs. 5 and 6) into the large chest or bin B, for ground malt, situated immediately over the mashing-tun D. The malt is reserved in the bin. Brewing till wanted, and it is then let down into the mashing-tun, where the extract is obtained by hot water supplied from the copper G.
The water for the service of the brewery is obtained from the well E, by a lifting pump worked by the steam-engine; and the forcing-pipe f of this pump conveys the water up to the large reservoir or water-back F, placed at the top of the engine-house. From this cistern iron pipes are laid to the copper G, and also every part of the establishment where cold water can be wanted for cleaning and washing the vessels. The copper G can be filled with cold water by only turning a cock; and the water, when boiled therein, is conveyed by the pipe g into the mashing-tun D. It is introduced beneath a false bottom, upon which the malt lies, and, rising up through the holes in the false bottom, it extracts the saccharine matter from the malt; a greater or less time being allowed for the infusion, according to circumstances. The instant the water is drawn off from the copper, fresh water must be let into it, in order to be boiled ready for the second mashing; because the copper must not be left empty for a moment, otherwise the intense heat of the fire would melt the bottom. For the convenience of thus letting down at once as much liquor as will fill the bottom of the copper, a pan or second boiler is placed over the top of the copper, as seen in fig. 3, Plate CXLII.; and the steam rising from the copper communicates a considerable degree of heat to the contents of the pan, without any expense of fuel. This will be more minutely explained hereafter.
During the process of mashing, the malt is agitated in the mash-tun, to expose every part to the action of the water. This is done by a machine contained within the mash-tun, and put in motion by the horizontal shaft H, leading from the mill. The mashing-machine is shown in fig. 1, Plate CXLII. When the mashing is finished, the wort or extract is drained down from the malt, into a vessel I, of similar dimensions to the mash-tun, and situated immediately beneath, from which it is called the underback. Here the wort does not remain longer than is necessary to drain off the whole of it from the tun above. It is then pumped up by the three-barrelled pump k, into the pan at the top of the copper, by a pipe which cannot be seen in the plate.
The wort remains in the copper pan until the water for the succeeding mashings is discharged from the copper. But this waiting is no loss of time, because the heat of the copper, and the steam arising from it, makes the wort, which had become cooler, ready for boiling. The instant the copper is empty, the wort is let down from the pan into the copper, and the second wort is pumped up from the underback into the copper pan. The proper proportion of hops is thrown into the copper through the near hole, and then the door is shut down, and screwed fast, to keep in the steam, and cause it to rise up through pipes into the pan; and by bubbling up through the wort in the pan, it communicates so much heat that it is soon ready for boiling in its turn; for it is to be observed, that the different worts follow each other through all the different vessels with the greatest regularity, so that there is no loss of time, but every part of the apparatus is constantly employed. When the boiling of the wort has continued a sufficient time to coagulate the grosser part of the extract and to evaporate part of the water, the contents of the copper are run off through a large cock into the jack-back K, which is a vessel of sufficient dimensions to contain it, and provided with a bottom of cast-iron plates, perforated with small holes, through which the wort drains and leaves the hops. The hot wort is drawn off from the jack-back through the pipe h by the three-barrelled pump, which throws it up to the coolers L, this pump being made with different pipes and cocks of communication, to serve all the purposes of the brewery except that of raising the cold water from the well. The coolers L are very shallow vessels, built over one another in several stages; and that part of the building in which they are contained is built with open lattice-work on all sides, to admit the free current of air. When the wort is sufficiently cooled to be put to the first fermentation, it is conducted in pipes from all the different coolers to the large fermenting vessel or gyle-tun M, which, with another similar vessel behind it, is of sufficient capacity to contain all the beer of one day's brewing.
When the first fermentation is concluded, the beer is drawn off from the great fermenting vessel M into the small fermenting casks or cleansing vessels N, of which there are a great number in the brewery. They are placed four together, and to each four a common spout is provided to carry off the yeast, and conduct it into the troughs placed beneath. In these cleansing vessels the beer remains till the fermentation is completed, and it is then put into the store-vats, which are casks or tuns of an immense size, where it is kept till wanted, and is then drawn off into barrels and sent away from the brewery. The store-vats are not represented in the plate, but are of a conical figure, and of different dimensions, from fifteen to forty feet diameter, and usually twenty feet in depth. The steam-engine which puts all the machinery in motion is explained by the figure. On the axis of the large fly-wheel is a bevelled cog-wheel, which turns another similar wheel upon the end of a horizontal shaft, which extends from the engine-house to the great horse-wheel, which it turns by means of a cog-wheel. The horse-wheel puts in motion all the pinions for the mill-stones W, and also the horizontal axis which works the three-barrelled pump A. The rollers a are turned by a bevelled wheel upon the upper end of the axis of the horse-wheel, which is continued for that purpose; and the horizontal shaft H, for the mashing engine, is driven by a pair of bevelled wheels. There is likewise a sack-tackle, which is not represented. It is a machine for drawing up the sacks of malt from the court-yard to the highest part of the building, whence the sacks are wheeled on a truck to the malt-loft A, and the contents of the sacks are thrown in.
The horse-wheel is intended to put in horses occasionally if the steam-engine should fail; but these engines are now brought to such perfection that it is very seldom any accidents occur with them.
Fig. 2, Plate CXLII., is a representation of the fermenting-house at the brewery of Messrs Whithread and Company, Chiswell Street, London, which is by far the most complete in its arrangement of any work of the kind, and was erected after the plan of Mr Richardson, who conducts the brewing at those works. The whole of fig. 2 is to be considered as devoted to the same object as the large vessel M and the casks N, fig. 1. In fig. 2, r is the pipe which leads from the different coolers to convey the wort to the great fermenting vessels or squares M, of which there are two, one behind the other; f represents a part of the great pipe which conveys all the water from the well E, fig. 1, up to the water cistern F. This pipe is conducted purposely up the wall of the fermenting-house, fig. 2, and has a cock in it, near r, to stop the passage. Just beneath this passage a branch-pipe p proceeds and enters a large pipe x x, which has the former pipe r within-side of it. From the end of the pipe x, nearest to the squares M, another branch n n proceeds, and returns to the original pipe f, with a cock to regulate it. The object of this arrangement is to make all, or any part of, the cold water flow through the pipe x x, so as to surround the wort-pipe r, which is only made of thin copper, and lower the temperature of the wort passing through the pipe r, Brewing, until, by the thermometer, it is found to have the exact temperature which is desirable before it is put to ferment in the great square M. By means of the cocks at n and p, the quantity of cold water which shall pass in contact with the surface of the pipe r can be regulated at pleasure, so as to have a command of the heat of the wort when it enters into the square.
When the first fermentation in the squares M is finished, the beer is drawn off from them by pipes marked v, and conducted by its branches w to the different rows of fermenting-tuns marked NN, which fill all the building. Between every two rows are placed large troughs to contain the yeast which they throw off. The plate shows that the small tuns are all placed on a lower level than the bottom of the great vessels M, so that the beer will flow into them, and, by standing in them all, will fill them to the same level. When they are filled, the communication-cock is shut; but as the working off of the yeast diminishes the quantity of beer in each vessel, it is necessary to fill them up again. For this purpose the two large vats OO are filled from the great vessels M before any beer is drawn off into the small casks N, and this quantity of beer is reserved at the higher level for filling up. The two vessels OO are in reality placed between the two squares M, but we have been obliged to place them so that they can be seen. Near each filling-up tun o is a cistern t, with a pipe of communication from the tun O, and this pipe is closed by a float-valve. The small cisterns t have always a communication with the pipes which lead to the small fermenting vessels N, and therefore the surface of the beer in all the tuns and in the cisterns will always be at the same level; and as this level subsides by the working off of the yeast from the tuns, the float sinks and opens the valve, so as to admit a sufficiency of beer from the filling-up tuns o to restore the surfaces of the beer in all the tuns, and also in the cistern t, to the original level. In order to carry off the yeast which is produced by the fermentation of the beer in the tuns OO, an iron dish or vessel is made to float upon the surface of the beer which they contain; and from the centre of this dish a pipe o descends and passes through the bottom of the tun, being fitted through a collar of leather so as to be tight, at the same time that it is at liberty to slide down as the surface of the beer descends in the tun. The yeast flows over the edge of this dish, and is conveyed down the pipe to a trough beneath.
Beneath the fermenting house are large arched vaults P, built with stone, and lined with stucco. Into these the beer is let down when sufficiently fermented, and is kept till wanted. These vaults are used at Mr Whitbread's brewery instead of the great store-vats of which we have before spoken, and are in some respects preferable, because they preserve a great equality of temperature, being beneath the surface of the earth.
Figs. 3, 4, and 7, Plate CXLI., represent the malt-rollers, or machine for bruising the grains of malt. A is the hopper into which the malt is let down from the malt-soft above, and from this the malt is let out gradually through a sluice or sliding-shuttle a, and falls between the rollers BD. These rollers are made of iron, truly cylindrical, and their pivots are received in pieces of brass let into iron frames, which are bolted down to the wooden frame of the machine. A screw E is lapped through the end of each of these iron frames; and by these screws the brasses can be forced forwards, and the rollers made to work closer to each other, so as to bruise the malt in a greater degree. G is the shaft by which one of the rollers is turned, and the other receives its motion by means of a pair of equal cog-wheels H, which are fixed upon the ends of the pivots, at the opposite ends of each of the rollers; d is a small lever, which bears upon the teeth of one of these cog-wheels, and is thereby lifted up every time a cog passes. This lever is fixed on the extremity of an axis, which passes across the wood frame, and in the middle of it has a lever e (3 & 7), bearing up a trough b, which hangs under the opening of the hopper A. By this means the trough b is constantly jogged, and shakes down the malt regularly from the hopper A, and lets it fall between the rollers; e is a scraper of iron plate, which is always made to bear against the surface of the roller by a weight, to remove the grains which adhere to the roller.
Fig. 5 is the screw by which the ground or bruised malt is raised up, or conveyed from one part of the brewery to another. K is an inclined bar or trough, in the centre of which the axis of the screw H is placed; and the spiral iron plate or worm, which is fixed projecting from the axis, and which forms the screw, is made very nearly to fill the inside of the box. By this means, when the screw is turned round by the wheels EF, or by any other means, it raises up the malt from the box d, and delivers it at the spout G. Fig. 6 represents a section of the screw.
The screw is equally applicable for conveying the malt horizontally in the trough k as inclined; and similar machines are employed in various parts of breweries for conveying the malt wherever the situation of the works require.
Fig. 1, Plate CXLI., is the mashing-machine. WW is the tun, made of wood staves, hooped together. In the centre of it rises a perpendicular shaft NN, which is turned slowly round by means of the bevelled wheels KI at the top. RR are two arms projecting from the axis, and supporting the short vertical axis S at the extremities, so that, when the central axis is turned round, it will carry the axle S round the tun in a circle. The axis S is furnished with a number of arms T, which are shown in fig. 2, and have blades placed obliquely to the plane of their motion. When the axis is turned round, these arms agitate the malt in the tun, and give it a constant tendency to rise upwards from the bottom.
The motion of the axis S is produced by a wheel Q on the upper end of it, which is turned by a wheel P fastened on the lower end of the tube O, which turns freely round upon the central axis N. On the upper end of the same tube O is a bevelled wheel M, receiving motion from a wheel L, which is fixed upon the end of the horizontal axis F, which gives motion to the whole machine. This same axis has a pinion G upon it, which gives motion to the wheel H, fixed upon the end of a horizontal axle, which at the opposite end has a bevelled pinion I working the wheel K, before mentioned. By this means the rotation of the central axis N will be very slow compared with the motion of the axis S; for the latter will make seventeen or eighteen revolutions on its own axis in the same space of time that it will be carried once round the tun by the motion of the axis N. At the beginning of the operation of mashing, the machine is made to move with a slow motion; but, after having wetted all the malt by one revolution, it is made to revolve quicker. For this purpose the ascending shaft A, which gives motion to the machine, has two bevelled wheels BC fixed upon a tube X, which is fitted upon the shaft. These wheels actuate the wheels D and E upon the end of the horizontal shaft F; but the distance between the two wheels B and C is such, that they cannot be engaged both at once with the wheels D and E; but the tube X, to which they are fixed, is capable of sliding up and down on the axis A sufficiently to bring either wheel B or C into action with its corresponding wheel E or D upon the horizontal shaft; and as the diameters of BE and CD are of very different proportions, the velocity of the motion of the machine can Brewing may be varied at pleasure by using one or other: b and c are two levers, which are forked at the ends, and embrace collars at the ends of the tube X; and the levers being united by a rod, the handle b gives the means of moving the tube X and its wheels BC up or down to obtain the action of the different wheels.
Figs. 3 and 4 represent a large close copper. AA is the copper, and B the pan placed over it. The copper has a large tube E rising up from the dome of it, to convey the steam; and from the top of this four inclined pipes R descend, the ends being immersed beneath the surface of the water or wort contained in the pan. By this means the steam which rises from the copper issues from the ends of the pipes R, and rises in bubbles through the liquor in the pan, so as to heat it. In the centre of the copper is a perpendicular spindle a, which, at the lower end, has arms dd fixed projecting from it, and is turned round by a cog-wheel b at the upper end. From the arms dd chains are hung in loops, which drag round upon the bottom of the copper when the axis is turned; and this motion stirs up the hops to keep them from burning at the bottom: fg is a chain and roller to draw up the spindle a when the rowser is not wanted: and ee are iron braces proceeding from the outside of the copper, to retain the axis a firmly in the centre of the copper. D is the waste-pipe for carrying off the steam into the chimney when it is not required to heat the liquor in the pan. The copper represented in the drawing is made in the same manner as usual; but the fire is applied beneath it in a manner very different from the common brewing-coppers. The method was devised with a view to the burning or consuming of the smoke, and was employed in the brewery of Messrs Meux and Company, London, about the year 1803.
The fire-place is divided into two by a wall extended beneath the bottom of the boiler, as shown by Z in the plan, fig. 4, where the dotted circle A represents the bottom of the copper, and the circle X its largest part. The section in fig. 3 shows only one of these fire-places, of which C is the fire-grate. The raw coal is not thrown through the fire-door in the manner of common furnaces, but is put into a narrow inclined box of cast-iron h, built in the brick-work, and shaped like a hopper. The coals contained in this hopper fill it up, and stop the entrance of the air so as to answer the purpose of a door; and the coals at the lowest part or mouth of the hopper are brought into a state of ignition before they are forced forwards into the furnace, which is done by introducing a rake or poker at i, just beneath the lower end of the hopper h, and forcing the coals forwards upon the grate bars C. Immediately over the hopper h, a narrow passage is left to admit a stream of fresh air along the top of the hopper to pass over the surface of the fuel which is burning at the lower end of the hopper h. By this means the smoke rising from that portion of fuel is carried forwards over the burning coals upon the grate C, and is thereby consumed. Beyond the grate bars e, a breast wall S is erected, to direct the flame upwards against the bottom of the boiler A, and thence descending under the bottom, the flame is received into the flues, which make each a half turn round the lower part of the copper, as shown in the plan at u, and then enter the chimney or perpendicular flue W at the same point; the entrance being regulated by a damper to make the draught more or less intense. There is also a sliding door or damper E, which closes up the lower part of the chimney; and by means of these two dampers the fire under the copper can be regulated to the greatest precision; for by opening the damper E it admits the cold air to enter immediately into the chimney W, and thus take off the rapidity of the draught; and at the same time, by closing the dampers from the flues into the chimney, the intensity of the draught through the fire is checked, which is very necessary to be done when the contents of the copper are drawn off. Immediately over the fire-grate e, an arch of fire-bricks or stone s is placed beneath the bottom of the copper, to defend it from the intense heat. The chimney is supported on iron columns RR. Behind the fire-grate e is a cavity r, for the reception of the masses of scoriae which are always formed in so large a fire. They are pushed back off the grate into this receptacle with an iron hook as fast as they accumulate. The bottom of this receptacle is formed of sliding iron doors, which can be opened by drawing them out, and in this way the clinkers are discharged; or the whole of the fire may be driven back off the grate into this cavity, and will then fall through into the ash-pit and be carried away therefrom, which is very necessary to be done when the copper is to be cooled, so that men may descend into it to clean out the sediment which is left after boiling the wort. For a more particular description of this method of setting boilers, see Philosophical Magazine, vol. xvii.
Fig. 6 represents one of the sluice-cocks which are used to make the communications of the pipes with the pumps or other parts of the brewery. BB represents the pipe in which the cock is placed. The two parts of this pipe are screwed to the sides of a box CC, in which a slider A rises and falls, and intercepts at pleasure the passage of the pipe. The slider is moved by the rod a, which passes through a stuffing-box in the top, the box which contains the slider, and has the rack b fastened to it. The rack is moved by a pinion fixed upon the axis of a handle e, and the rack and pinion is contained in a frame d, which is supported by two pillars. The frame contains a small roller behind the rack, which bears it up towards the pinion, and keeps its teeth up to the teeth of the pinion. The slider A is made to fit accurately against the internal surface of the box C, and it is made to bear against this surface by the pressure of a spring, so as to make a perfectly close fitting.
Fig. 5 is a small cock to be placed in the side of the great store-vats, for the purpose of drawing off a small quantity of beer, to taste and try its quality. A is a part of the stave or thickness of the great store-vat; into this the tube B of the cock is fitted, and is held tight in its place by a nut aa screwed on withinside. At the other end of the tube B a plug e is fitted, by grinding it into a cone, and it is kept in by a screw. This plug has a hole up the centre of it, and from this a hole proceeds sideways and corresponds with a hole made through the side of the tube when the cock is open; but when the plug e is turned round, the hole will not coincide, and then the cock will be shut. D is the handle or key of the cock, by which its plug is turned to open or shut it; this handle is put up the bore of the tube (the cover E being first unscrewed and removed), and the end of it is adapted to fit the end of the plug of the cock. The handle has a tube or passage bored up it to convey the beer away from the cock when it is opened, and from this the passage f, through the handle, leads to draw the beer into a glass or tumbler. The hole in the side of the plug is so arranged, that when the handle is turned into a perpendicular direction with the passage f downwards, the cock will be open. The intention of this contrivance is, that there shall be no considerable projection beyond the surface of the tun; because it sometimes happens that a great hoop of the tun breaks, and, falling down, its great weight would strike out any cock which had a projection; and if this happened in the night much beer might be lost before it was discovered. The cock above described being