Dairy or Dairying, that branch of husbandry of which the object is to convert the produce of the soil into milk, by means of the domesticated animals, and to prepare it for use in different forms.
The only animal kept in considerable numbers for its milk, in this country, is the cow. Though it is still the practice in some parts of Britain to draw a quantity of milk from ewes, after their lambs are weaned, and a few goats and asses are kept chiefly for their milk; yet in the case of sheep, the milk is a very subordinate part of the produce, and the medicinal quality of the milk of the two latter species of animals, of which the number is quite inconsiderable, does not allow them to be considered as part of a dairy stock.
Milk is used either in the state in which it is drawn from the cow, or, after its component parts have been separated, in the shape of cream, or butter, or cheese, with butter milk, skimmed milk, or whey. Hence, to give a general view of this branch of husbandry, it is necessary to arrange dairies under three great divisions, according to the principal object of each, namely, new milk, butter, and cheese dairies. Nor is it any objection to this arrangement, that, at certain seasons of the year, or owing to temporary causes, it may be found necessary to unite the labours of all the three in any one of these divisions. It is enough that the chief purpose and general management be different, to entitle them to separate consideration, because these take their rise in the very different circumstances of each class, and give to it a determinate character. The treatment of the cows, and the value of their produce, are by no means the same in all the three, and the animals themselves would require to be selected with a view to the particular object of each; the cow that yields the greatest quantity of milk, and is on this account preferred for a new milk dairy, not being always the most profitable one in a cheese or butter dairy.
1. New Milk Dairies.—It is only in or near large towns that dairies of this description can be established upon a scale of any extent, and there they are found in great variety. It will give a sufficient view of what may be considered the best systems of management, to mention the practice of the London and Edinburgh dairymen.
1. The cows kept for supplying the metropolis with milk are of a large size, with short horns, and known by the name of Holderness cattle, from a district of that name in Yorkshire, though they do not now all come from thence, but many of them from a similar stock in that and the neighbouring counties. They are bought from the breeders when three or four years old, and in calf, and exposed by the dealers at the fairs and markets in Middlesex, particularly at Islington, where there is a fresh supply from the country every week; by means of which the London cow-keepers are enabled to keep up their stocks. These cows are preferred on account of the quantity of their milk, without much regard to its quality. A few of the cow-keepers have very large stocks, nearly a thousand having been sometimes in the possession of one individual. The whole number required for the supply of London and its environs with milk is about 8500, the produce of which a few years ago was estimated at £38 a year each, or £323,000 in all, said to yield a profit of £6 per cow to their owners. But the sum actually paid for milk, including the profits of the retailer, has been stated at L626,233 per annum.
The cow-keepers breed very few cattle, and those only from favourite cows, which become so merely from their giving much milk, and with very little attention to the choice of their bulls. Cows of this description are usually kept five, or even sometimes seven years. When they are allowed to become dry, with a view to their being disposed of, they soon become fat on their former diet, and are then sold to the butcher.
During the night the cows are confined in stalls. About three o'clock in the morning each has an half bushel basket of grains, to which salt, not much more than an ounce a day, is sometimes added. From four o'clock to half past six they are milked by the retail milk-dealers, who contract with the cow-keepers for the milk of a certain number of cows, at so much for eight quarts. When the milking is finished, a bushel basket of turnips is given to each cow; and very soon afterwards they have an allotment, in the proportion of one truss to ten cows, of grassy and soft meadow hay, which had been the most early mown, and cured of the greenest colour. These several feedings are generally made before eight o'clock in the morning, at which time the cows are usually turned into the cow-yard, though in one large dairy at Islington they are constantly confined to the stake. About twelve o'clock they are again confined to their stalls, and served with the same quantity of grains as they had in the morning. About half past one o'clock in the afternoon, the milking commences in the manner before described, and continues till near three, when the cows are again served with the same quantity of turnips, and, about an hour afterwards, with the same distribution of hay. Along with, or instead of turnips, mangel wurzel is now much used in these dairies.
This mode of feeding generally continues during the turnip season, which is from the month of September to the month of May. During the other months of the year they are fed with grains, cabbages, tares, and the foregoing proportion of rouen, or second cut meadow-hay, and are continued to be fed and milked with the same regularity as before described, until they are turned out to grass, when they continue in the field all night; and even during this last period they are frequently fed with grains, which are kept sweet and eatable for a considerable length of time, by being buried in pits made for that purpose. There are about ten bulls to a stock of three hundred cows. The calves are generally sent to Smithfield market at one, two, or three days old. The quantity of milk given by each cow, on an average, is nine quarts a day, or 3285 quarts in the year. The weekly expense of food is estimated in the Middlesex report at 10s. 3d. and the other charges about L5. 7s. per annum. In 1807, the retailer paid to the cow-keeper for the milk 2½d. and sold it to the consumer at 4½d. per quart; but it is alleged, that by taking off cream, difference of measure, and other means, the retailer obtains a profit of no less than a hundred per cent.
Five or six men only are employed in attending nearly three hundred cows. As one person cannot milk more than eight or nine cows twice a day, that part of the business would necessarily be attended with considerable expense to the cow-keeper, were it not that the retailer, as before observed, agrees for the produce of a certain number of cows, and takes the labour and expense of milking upon himself.
Every cow-house is provided with a milk room, where the milk is measured, and served out by the cow-keeper; and this room is commonly furnished with a pump, to which the retail dealers are said to apply in rotation, not secretly, but openly, before any person who may be standing by, from which they pump water into the milk vessels at their discretion. The pump is placed there expressly for that purpose, and it is seldom used for any other.
2. The greater part of the cows kept in Edinburgh are also of the short-horned breed, brought from the counties of Berwick, Roxburgh, and Northumberland, and weigh, when fat, from forty to sixty stones avoirdupois. They are purchased by dealers, who drive them to market when they are about to calve, or immediately after calving. Many of them are too old for being kept to advantage on the usual food allowed them in the country, or to be fattened on turnips; and part of them are purchased from hinds or married ploughmen, who have no means of fattening them. A cow which shows a great deal of milk sells in Edinburgh nearly as high as a fat cow of the same weight.
The cow-feeders of Edinburgh do not find it for their interest to keep their cows for more than one year, or even so long, if they can be fattened sooner. Their object is to have as great a quantity of milk as possible in the first instance; and when the cows fall off in milking, as they almost always do between four and six months after calving, to prepare them speedily for the butcher. Most of the cows continue to give a good deal of milk while they are fattening, and even until they are sent to the shambles. It is expected they should sell to the butcher at the price paid by the cow-keeper.
Their food in summer is brewers' and distillers' grains, and wash or dreg, wheat shellings or small bran, grass, and straw; and in winter the same grains, dreg, and bran, with turnips and potatoes, and hay instead of grass. When grains are scarce, cut or chopped hay is mixed with them. Some of them are sent to pasture in fields near the city for about two months during the best of the grass season; but even then a certain number must be kept in the house, for consuming the grains, which are usually purchased by contract for a whole year.
With regard to management, the cow-keepers begin with grains, dreg, and bran, mixed together, at five o'clock in the morning; feed a second time at one o'clock afternoon, and a third from seven to eight in the evening. Grass in summer, and turnips or potatoes in winter, are given at both intervals. A small quantity of straw is laid below the grass, which absorbs its moisture, and is eaten after the grass; and, in winter, straw or hay is given after the turnips. Part of the turnips or potatoes is boiled, particularly when there is a scarcity of grains, and intermixed with them. The expense in summer is said to be 2s. 10½d., and in winter 3s. 7½d. per day, for each cow. The cows are seldom milked more than twice a day; but for about a month after being bought, it is sometimes necessary to milk them three times. The common periods of milking are six o'clock in the morning, from three to four in the afternoon, and, when milked a third time, nine in the evening.
Their produce in milk, when fed as already stated, may average about seven Scotch pints, or nearly twelve quarts and a half, daily, per cow. When the cows are smaller, and not so well fed, five pints, or about nine quarts, is said to be the average. The price of milk in Edinburgh used to be 6d. per pint, but of late it has been lower, particularly in summer. This is said to be very little more than the price of the food. For interest of money, risk, expenses of management, and profit, there is the manure, worth L3. 10s. for each cow; some savings on the cows while at grass, which costs only 1s. 8d. per day; and probably a small advance of price may be commonly got from the butcher when the cows are skilfully selected and well managed.
There have been instances of cow-feeders contracting with others to retail their milk; but the practice is not common. The cow-keepers generally retail it themselves. In one instance a guinea a week for the milk of each cow was paid by retailers to a farmer in the vicinity of Edinburgh.
Comparing the London and Edinburgh dairies, there seems to be a difference in favour of the best of the latter, of no less than three quarts and a half per day. If this be the fact, perhaps it is owing to the whole of the Edinburgh cows being always in milk, none of them being kept for years and bred from, as in the London dairies.
An extensive dairy was carried on a few years ago at Glasgow, by Mr Williams Harley, and conducted with an attention to the health and comfort of the animals, and the purity of the milk, that has probably had no parallel in Britain. The cows were of the Ayrshire breed, bought in generally either newly calved, or a few weeks before calving, and kept constantly in the house till they were sent to the butcher. Their food was much the same as in the Edinburgh dairies; but the turnips and potatoes given in winter were always prepared with steam. The average quantity of milk was eleven quarts daily from each cow, and it was delivered to the consumer from vessels so constructed and secured as to prevent adulteration in its passage from the dairy. This establishment, which was an interesting object to strangers, exists no longer.
II. Butter Dairies.—This class is not confined, like the former, to the immediate neighbourhood of towns, yet the principal ones are situated at such a moderate distance as to allow of their produce being sent thither in a fresh state. Butter is made, indeed, in every part of the country, but it is nevertheless the chief object of a great number of dairies, which therefore form one leading division in this department of husbandry.
It does not appear that any particular breed of cows, as in milk dairies, is selected as most suitable for dairies of this description; nor that their food and general management differ materially from those of cows kept for other purposes. Even in dairies of this class, butter, though the chief object, is not one so exclusive as to prevent the cows from being employed as a breeding stock. With this last view they are almost of every different variety, according as one or other breed is considered as the most profitable, upon the whole, in different situations. They are commonly the breed of the district where the dairy is situated, and not, like the short horns kept in milk dairies, brought from other quarters, with a particular view to this description of produce. For an account of these breeds, see the article Agriculture.
Butter is made either from cream taken from the milk, or from the milk itself; the former method, however, being still the most common. The best cream will be ready for the skimming dish in seven or eight hours, though twelve is the more usual period; and, according to the state of the weather, it is allowed to stand from three to seven days before it is put into the churn. The best temperature at commencing the operation of churning is from fifty to fifty-five degrees, and it should never exceed sixty. The practice of churning the whole milk, which has long prevailed, particularly in the western counties of Scotland, does not seem to be generally known. Mr Marshall, in his review of the original report of Cheshire, printed in 1794, mentions it in 1810, as a singular variety in the English butter dairy, that in Cheshire the milk and cream are churned together without any previous separation.
The practice as it prevails in Scotland has been thus described. The milk, when drawn from the cow, is placed in coolers about three inches deep, and stands from twelve to twenty-four hours; when the cream has risen to the surface, the coolers are emptied into a stand-vat, where the milk remains till churned. If another milking is ready to be placed in the stand-vat before the former has begun to sour, the second also may be put into it; but if the first has soured, or is approaching to it, such admixture, it is said, would lead to fermentation, and injure the milk. The utmost care is always taken not to allow the coagulum of the milk in the stand-vat to be broken till it is about to be churned. If the house be of a proper temperature, the milk may stand from a day to a week without injury, till as much be collected as it may be convenient to churn at a time. No milk is ever churned till it has become acid and coagulated.
The operation is generally performed in plunge-churns of considerable size. Some of them, containing 120 Scotch pints, are worked by a single person; and when machinery is applied, 150 or 200 pints are churned at a time. In a few minutes after the operation begins, as much warm water is poured into the churn as raises the temperature of the milk from fifty to fifty-five degrees of Fahrenheit (being that of the dairy house), to seventy or seventy-five degrees; the churning always going on while the water is slowly poured in. The milk will admit of a greater proportion of water in autumn, when it is rich, than in spring, when it contains more serum. Probably one pint of water may generally be added, one way or other, to every five or six Scotch pints of milk in the early part of summer, and one to four or five in winter. A certain proportion is considered indispensable, both for raising the cream and facilitating churning; but it is alleged that too much is often employed, for the purpose of adding to the quantity of the butter-milk. When milk is either overheated, or churned too hastily, the butter is always soft, and of a white colour. From two to three hours is a proper time for performing the operation of churning.
In Renfrewshire, where nearly all the milk is employed in the manufacture of butter and butter-milk, cows have been hired by the year at L.13 or L.14.
The average yearly produce per cow of the butter-dairies of England, according to Mr Marshall, is three firkins, of fifty-six pounds each. In Buckinghamshire the rate is higher, a cow yielding five pounds per week for forty weeks, or more than three and a half firkins. The annual consumption of London has been computed at 50,000 tons, or two millions of firkins, which, at the rate of three firkins per cow, is equal to the butter produce of 667,000 cows. This would be in the proportion of three quarters of a hundredweight to every individual in the population, which is probably much above the truth; but the demands for the shipping and other purposes must be very considerable.
The packing, salting, and selling of butter are regulated by statutes, of which the most important is the 38th Geo. III. c. 86. By these it is enacted, that every vessel made for the packing of butter shall be marked with the maker's name and place of abode, and its own weight, and shall be of a size to contain eighty-four pounds, called a tub, or a firkin to contain fifty-six pounds, or a half firkin of twenty-eight pounds; and severe penalties are imposed for the breach of these, and a variety of other regulations for the prevention of fraud.
The manufacture of butter leaves a large proportion of the milk applicable to other purposes. When the whole milk is churned, the residuum is called butter-milk, which is sold in towns at a penny per Scotch pint (about two imperial quarts), and when delivered in a cleanly and pure state, it is esteemed a wholesome and nutritious article of food by the labouring classes. If the cream only is employed, there remains skimmed or sour milk, which in some places, as in Buckinghamshire, where it is reduced by repeated skimmings for cream, is given to hogs; but it is more commonly made into inferior cheese, yielding whey as the last product, for the feeding of hogs. III. Cheese Dairies.—The English cheeses in greatest repute are the Stilton, the Cheshire, and the Gloucester. In making the first, “the night’s cream is put to the morning’s milk with this runnet;” the curd is not broken, but allowed to drain gradually in a sieve, and gently pressed till it becomes somewhat firm and dry; after which it is placed in a box made exactly to fit it, and then bound with cloths till it acquires sufficient firmness to support itself. After the cloths are removed every cheese is brushed once a day for two or three months. It is not considered as ready for use until it is two years old. The cheese of Cheshire and Gloucester are made of the whole milk and cream, excepting that part of the cream is abstracted in the single Gloucester. The runnet in general use is a pickle, prepared from the maw or stomach of a calf, of which somewhat less than half an imperial pint suffices for fifty gallons of milk; and when the cheese is to be coloured, an ounce of Spanish arnotto will serve for an hundredweight.
At the time of setting the curd, the temperature of the milk, according to Mr. Marshall, should be from 85° to 90°, and should not, during the process, be allowed to lose more than 5° or 7°. When the coagulation has taken place, the curd is repeatedly broken or cut with a knife, and the whey drawn off; and then, after salt has been intimately mixed with it, it is packed into a vat with holes in the bottom, over which a cloth has been spread, and with which it is covered up and put into the cheese press. Here it usually remains the first time for two hours, after which it is taken out and put into a vessel of hot whey for an hour or two to harden its skin, and again, wrapped in fresh dry cloths, submitted to the action of the press from time to time. In one of these intervals it is rubbed with salt, sweated, and its rough edges or other projections are carefully pared away. When finally removed from the press to the room where it is to be kept, which should be cool and dry, it is turned at first every day, and afterwards at short intervals, until it is ready for use.
Besides the cheeses made in Scotland in imitation of the English kinds, Ayrshire and the other western counties have long been noted for what is called Dunlop cheese, of which the following account has been collected from the Agricultural Reports.
When such a number of cows are kept as to yield milk sufficient for a cheese of tolerable size, at every milking the milk is passed through a sieve, provincially termed a milsey, to remove impurities, into a boyne or vat, and formed into curd by a mixture of runnet. As milk requires to be coagulated as nearly as possible at its heat when drawn from the cow, and as it must cool somewhat in milking and passing through the sieve, it is necessary to pour a quantity of warm water into it in the curd-vat.
Where the cows on a farm are not so numerous as to give milk sufficient to make a cheese every time they are milked, the milk is stored about three or four inches deep in coolers, till as much is collected as will form one of a proper size. When the cheese is to be made, the cream is skimmed from the milk in the coolers, and, without being heated, is passed through a sieve or drainer, along with the milk which is drawn from the cows at the time, into the curd-vat; and the skimmed milk being heated, so as to raise the temperature of the whole mass to about the heat of new milk, and also passed through the drainer, the whole is coagulated by runnet, carefully mixed with the milk. The cream is put into the curd-vat cold, that its oily parts may not be melted.
The temperature at which the milk is kept, from the time it is drawn from the cows till it is formed into cheese, ought to be carefully attended to. To make it cool, and to facilitate the rising of the cream, a small quantity of cold water is generally poured into each cooler. If kept much warmer than 55 degrees of Fahrenheit, it will not properly cast up the cream, a thing necessary, even when the whole is to be formed into cheese; and it will very soon become sour. And, if it gets into a lower temperature, the milk never coagulates so well; the cheese made from it is soft and inadhesive, and the whey is separated with difficulty. It is not enough that the temperature be raised to the proper degree when coagulated; if it has, prior to that, become too cold, the heat at setting the curd will not do away the bad effects of the previous cold. It is said to be owing to the milk being allowed to cool too much before it is coagulated, that it becomes difficult to get it formed into cheese in winter, and that the cheese made at that season is so soft and tasteless.
Whenever the milk has coagulated, the whey is drawn off as fast as possible; and, to facilitate its separation, the curd is minutely broken, or cut with a knife. When the whey has been mostly extracted, the curd is put into a drainer, and again cut and pressed, to expel it more completely. It is next broken small, minutely mixed with salt, and put into the cheese-vat, with a piece of thin canvass round it; and pressure is applied till the whey is wholly extracted and the cheese formed. It remains the first time about an hour, and afterwards three or four hours each time, in the press, getting a dry cloth, and its position being reversed, every time it is replaced. Skewers are never put into the sides of the cheese to extract the whey, as is common in England.
Some have of late shortened the process of pressing, by placing the cheese, when it comes from the press for the first time, into water heated to about 95 or 100 degrees, where it remains till the water falls to the heat of new milk. It is then dried well, and again placed under the press.
Salt is generally applied without measure or weight, but the proper rate is said to be about half an ounce to every pound of cheese, or thirteen ounces to twenty-four pounds.
When the cheeses come from the press, they are exposed for about a week to a considerable degree of drought, and turned over twice every twenty-four hours, and afterwards laid on boards in a close cool room, and turned over twice a week. The practice of sweating cheeses after they come from the press, and before they are laid up to dry, which is so common in England, is not approved of in Scotland, from an idea that it impoverishes the cheese, by melting part of its fat.
All the operations are carried on in Scotland by women. Men would think themselves degraded were they to assist in milking the cows or making the cheese.
Besides one or two meal cheeses, in which the milk is fresh or sweet, a great deal of cheese is made from milk from which cream has been taken, and which has therefore been allowed to stand longer. This may be considered as a subordinate branch of the butter dairy, where butter is made from cream, as is still the most general practice; but the process does not require to be described, as it is not materially different from that which prevails in what may be more properly called a cheese dairy. Suf-Skimmed folk has been long noted for cheese of this description, milk yet the celebrated Parmesan is said to be made of milk cheese, from which the cream has been taken; nor, in the process of its manufacture, as described in the Bath Papers (vol. vii.), and by Cadell in his Journey in Carniola (8vo, 1818), does there appear any thing worthy of particular notice, unless it be that the coagulation is effected in a cauldron suspended over a fire, and probably, therefore, at a higher temperature. The best kind of Parmesan is that which has been kept at least three years. The average yearly produce of cheese from the milk of a cow is, according to Marshall, from three to four hundredweight, or more than double the weight of butter. If four and a half quarts of milk commonly yield one pound of cheese, a cow that gives two thousand quarts in a year should produce about four hundredweight of cheese. It has been calculated that Cheshire alone makes no less than 11,500 tons in a year.
In many of the English cheese dairies, a quantity of inferior butter is obtained from the whey. In some parts of Gloucestershire, and in Cheshire, this produce is rated at half a pound per cow in the week, which sells at from a penny to twopence a pound less than milk butter. In some instances, what is called the "green whey," or that which is taken from the cheese-tub after the curd is formed, and the "white," or that which is expressed from the curd itself, are at first treated separately, the former being heated, as soon as it has parted with the curd, till it throws up a little white froth, and the latter set by till it is at least a day old. This last is then added to the furnace-pan that contains the green whey, from which mixture a substance is thrown up something in appearance between cream and curd, which is constantly skimmed off as long as it rises, and put into the cream mugs to be churned for butter. In the practice of other dairies the white whey only seems to be used, and, after standing some time in these mugs to acidulate for churning, the butter is obtained from it in the same way as from milk. The green and the white whey are, in other instances, both heated together, to which, if perfectly sweet, a little acid is sometimes added.
Whey, whether butter be made from it or not, is sometimes subjected to further operations, to fit it for human food. Fleatings, or flit-milk, made by pouring butter-milk upon whey, is a common beverage among the farm servants of Cheshire. But the purpose to which it is chiefly applied is the feeding of pigs, for which it is worth about a guinea for every cow. From the whey obtained from the milk of four cows, it has been calculated that a hog may, in one season, and with very little other food, be raised to the weight of twelve or fifteen stone.
On the subject of cream, a product common to all the three classes of dairies, though of greatest value in the situation proper to new milk dairies, that is, in or near towns, it is only necessary to observe, that the sale of it affords a ready resource whenever all the milk cannot be disposed of in a fresh state, and also when, from the season of the year, or other circumstances, the manufacture of cheese must be discontinued. But there is yet another branch of dairying that deserves attention, namely, the fatting of calves; and this also may be, and usually is, carried on, at least occasionally, at dairies of every description. As milk is their chief, and in most cases their only food, its employment in this way may be considered as merely another mode of preparing it for the use of man.
Calves are either suckled or fed from the pail. In the county of Middlesex, where a great many are fattened by the first mode, the calves are kept in pens of seven or eight feet square. There are seldom more than four calves in one pen, which has only one door, and that is towards the cows. Particular care is taken to keep these places free from dirt of every kind, and well bedded with clean straw. On one side of every pen is placed a small trough, at such a height as to prevent its receiving any soil; this is always kept supplied with chalk, both in lumps and in powder, not with a view to render the veal white, as some persons erroneously suppose, but with the intention of preventing acidity in the stomach. Without this precaution they would be liable to scour, which always prevents their thriving, and sometimes occasions the death of the animal. Some persons mix ground barley with the chalk, and others give them daily balls, made of linseed jelly and barley-meal, to render them more fat, or fat in less time than could be done with milk alone. They are suckled at precisely the same time every twelve hours, generally at six o'clock. Any considerable deviation in time would occasion their being fretful, and that would impede their becoming fat. In about ten weeks they make the best veal; though they are frequently continued eleven or twelve weeks, with increase of weight; but in that case the joints of meat become large, and the grain of the veal coarse. The large calves also sell at a less price per stone than such as are of a moderate size.
In the western counties of Scotland, where cheese dairies prevail, the calves are fed from the pail, suckling being considered as injurious to the cows; and as the cows will not readily suckle any but their own calves, a calf would thus be often confined to the milk of only one cow. It is the practice there to give to those that are to be reared the first drawn milk, which is thin, and abounds with serum; and to such as are fatting, the last drawn milk of two, or perhaps of three cows. They have no other food; and bleeding is never used with a view to expedite their fattening, as in some dairies. A little bacon or mutton broth is administered when a purgative is necessary; and rumnet is used for an opposite purpose if they begin to scour. But the ordinary management consists in merely supplying them with abundance of the richest milk, after the first two or three weeks, and keeping them dry, by means of plenty of litter, in a dark, well-aired apartment, not exposed to the extremes of either heat or cold.
The apartments required, and their arrangement, as well as the furniture and implements, necessarily depend upon the extent of the dairy establishment, and the main purpose for which it is carried on. In all, there should be a room for the milk separate from that in which the necessary operations are performed, or the produce stored up. The milking pails are of wood or tin, the latter preferable, as being more easily and thoroughly cleansed. The vessels in which the milk is deposited to throw up the cream, or the coolers, which are usually of a circular form, may be of wood, lead, pottery, or iron; the latter, when tinned within, with a plug which admits of the milk being drawn off, leaving the cream behind, have been much approved of. Of churns, some are wrought like a pump, called plunge churns, and others are of a barrel form, the apparatus for giving the necessary agitation to the milk being worked by a handle on the outside. The cheese press is commonly constructed of wood, and the power obtained by a screw, though sometimes by a lever with weights attached. Skimming dishes, and a variety of minor articles, in which there is nothing to require a detailed description, will naturally suggest themselves as indispensable in the management of every dairy.
The operations of the dairy, in all its branches, are still conducted perhaps more empirically than those of any other department of husbandry, though it would appear that science, chemistry in particular, might be applied to discover the principles and regulate the practice of the art with facility and precision. We have heard it admitted, even by experienced dairymen, that the quality of their cheeses differs materially in the same season, without their being able to assign a reason. Every one knows how different the cheese of Gloucester is from that of Cheshire, though both are made from fresh milk, the produce of cows of the same breed, or rather, in both counties, of almost every breed, and fed on pastures that do not exhibit any remarkable difference in soil, climate, or herbage. Even in the same district, some of what must appear the most important points are far from being settled in practice. Mr Marshall, in his Rural Economy of Gloucestershire, has registered a number of observations on the heat of the dairy-room, and of the milk, when the rummet was applied in cheese-making, on the time required for coagulation, and the heat of the whey afterwards, which are curious, only because they prove that no uniform rule is observed in any of these particulars. The same discrepancy is observable in all the subsequent operations, till the cheese is removed from the press, and even afterwards in the drying-room. One would think the process of salting the cheeses the most simple of all; and yet it is sometimes, as in the west of Scotland, mixed with the curd; in other instances, poured into the milk, in a liquid state, before being coagulated; and still more commonly little or none is applied till the cheeses are formed in the press, and then only externally in the salting-room. Our limits do not permit us to describe this great diversity of practice, nor is it necessary, as it does not appear which method is entitled to a preference.
As the first step towards scientific improvement in the practice of the dairy, it would be desirable to obtain a simple and accurate test of the quality of milk, or the proportion in which its three component parts, oleaginous, caseous, and serous, are combined in every instance. By means of this, it would not only be known beforehand what the produce of milk, in each of these parts, ought to be under correct management; but also, by applying it to the milk of different breeds, and of the same breed kept on different kinds of food, the most profitable description of cows, and the most beneficial mode of feeding them, according to the purpose for which their milk was to be employed, would in time be determined. The changes which are understood to take place in milk during the gestation of the animal, and at certain intervals from the period of its parturition, and such also as depend upon its age, might perhaps be detected by the habitual employment of such an instrument.
The importance of a test of this kind has not escaped the attention of ingenious men. Mr Dicas, a mathematical instrument-maker in Liverpool, and well known by his invention for trying the strength of spirituous liquors and worts, many years ago constructed what has been called a lactometer, an instrument for ascertaining "the richness of milk from its specific gravity, compared with water, by its degree of warmth taken by a thermometer, on comparing its specific gravity with its warmth." "If the principle be right," says the author of the Lancashire Report, "by this may be discovered not only the qualities of the milk of different cows, pastures, foods, as turnips, potatoes, grains, &c. but also probably which may be the best milk, or best pastures for butter, and which for cheese." Another invention for the same purpose came under the notice of the Highland Society of Scotland in June 1816, in a Report from a committee of their number, prepared by Dr Hope, professor of chemistry in the University of Edinburgh. The subject of it was the most aerometric beads, invented by Mrs Lovi of this city. The committee were of opinion that these beads might be introduced into the dairy with a reasonable prospect of practical utility. The importance of such a test, as well as the difficulty of obtaining one that would immediately indicate the quality of the milk, arising from the different specific gravities of its parts, and also the mode of using these beads, may be seen from the following observations of the committee:
"Milk is a compound fluid, consisting in a great measure of water, and owing its valuable qualities principally to the curd and butter which it contains. The richest milk abounds in oil and curd, and the poorest in water. As the oil is lighter than water, and the curd heavier, the quantity of these ingredients is not indicated by the specific gravity; for were these substances in milk in certain proportions, they would not affect the specific gravity of the fluid, however large the quantity of them might be, the one counteracting the other.
"Milk possesses a specific gravity greater than that of water, which it derives in part from the saccharo-saline matters belonging to the whey, and in part from the curd; and it approaches more nearly the specific gravity of water, the greater quantity of water it has, or the greater the proportion of cream. Hence a low specific gravity indicates either much richness or great poverty; and consequently, the gravity of this fluid is not an immediate indication of its quality. The information given by the beads will, however, be valuable, if the specific gravity be examined after the cream is removed, as well as before.
"When milk is tried as soon as it cools, say to 60°, and again after it has been thoroughly skimmed, it will be found that the skimmed milk is of considerably greater gravity; and as this increase depends upon the separation of the lighter cream, the amount of the increase, or the difference between the specific gravity of the fresh and skimmed milk, will bear proportion to, and may be employed as a measure of, the relative quantities of the oily matter or butter contained in different milks. In this manner, therefore, by discovering by these beads the difference in the specific gravity of milk when new, and after being skimmed, the relative values of this liquor for giving butter may be certainly and easily determined.
"The committee conceive that it would be of much importance to ascertain, by carefully-conducted experiments, the exact quantity of butter furnished by a given measure of milk of different degrees of richness, the specific gravities of which have been examined before and after the separation of the cream. By such experiments, the quantity of butter corresponding to each degree of change in the specific gravity may be determined; and then the aerometric beads will serve to indicate, not only the relative qualities of different milks, for the purpose of butter-making, but also the actual quantity of butter that any given quantity of milk ought to afford.
"That such information may prove of consequence in regulating the business of the dairy, is too obvious to require illustration.
"The specific gravity of skimmed milk depends both on the quantity of the saccharo-saline matters and of the curd. To estimate the relative quantities of curd, and by that determine the value of milk, for the purpose of yielding cheese, it is only required to curdle the skim milk, and ascertain the specific gravity of the whey. The whey will, of course, be found of lower specific gravity than the skimmed milk; and the number of degrees of difference affords a measure of the relative quantities of the curd.
"By a proper series of experiments, the quantity of cheese equivalent to each degree of the diminution of gravity in a given measure of this fluid, might be determined.
"Hence it appears to your committee, that the aerometric beads may be employed to explore the quality of milk, in relation both to the manufacture of butter and cheese; and your committee beg leave to direct the attention of the society to this subject."
On the subject of new milk dairies, see Holt's General View of the Agriculture of Lancashire, 1795; Middleton's