Cheese

Cheese is a highly nutritious food substance made from milk by elaborate processes which can only be explained in the light of a knowledge of science, chiefly chemistry. Cheeses may be roughly divided into two great classes—hard and soft. The various English, Scotch, and American cheeses belong to the first class, and are made so that they will generally keep for months, and often continue to improve in quality. Soft cheeses are those which prevail in some parts of the Continent. Many of them require to be consumed immediately after they are manufactured. Their rapid decomposition is associated with a strong and to most people an objectionable smell. Cheese is made from the solids of milk—viz. the casein or chief albuminoid constituent, along with the greater part of the cream or butter-fat, and much of the mineral ash. In fresh milk, which is slightly alkaline, these substances maintain a sort of indescribable union with the watery portion and the milk-sugar—the whole, as is well known, being liquid. The presence of an acid, or of Rennet (q.v.), counteracts the natural affinity of the substances for each other, and the bulk of the solids separate out, forming a soft jelly in the early stages, leaving the bulk of the water containing the sugar as a greenish liquid called Whey (q.v.). The chemical processes involved are as yet only very imperfectly understood.

Milk in decomposing, as it rapidly does in hot and sultry weather, becomes sour in virtue of a natural process of fermentation. Rennet induces another form of fermentation which does not end when the product ceases to be milk, but is carried on in the cheese during the period of its ripening or mellowing. In the early stages of the process of hard cheese-making, the incipient acidity which induces that condition in milk termed 'ripeness,' aids and hastens the action of the rennet. As the work proceeds, and the acidity intensifies, it hardens and contracts the curd, giving it a leathery character, thereby aiding in the expulsion of the whey. One of the most important matters in cheese-making is to watch the development of acidity both in the milk and its first product, the curd. If this is allowed to go too far, the quality of the cheese is seriously injured, and its keeping power is reduced. It cracks through becoming too dry and brittle. The delicate flavouring oils seem to be expelled, and the smell becomes high and the taste 'aerid' or 'biting.' The formation of the acid is one of the great helps in cheese-making so long as it is kept in due control. If the acid develops rapidly, as in hot weather, in a temperature which suits the germs producing it, the whole process of manufacture has to be pushed on quickly, whereas in cold weather acidity comes slowly, and the operator must wait until it has come sufficiently. There are several methods adopted in inducing acidity. Acid used to be largely added, as sour whey or buttermilk, but greater uniformity is got by delaying until natural acidity develops. This it does most quickly when the temperature of the material is kept up near to blood-heat. Chilly draughts paralyse the active organisms producing acidity.

Heat is communicated to milk or to its products in the early stages of cheese-making by two methods—either by warming a portion of the milk or whey (though not allowing it to rise much above 100° F.—say a limit of 150° F.—as to boil it would do injury by changing its constitution), and putting it into the main bulk, or by having an outer shell of wood to the tin or iron cheese-tub, with a space between into which steam or hot water can be injected. This arrangement possesses the additional advantage of being clean and of saving labour, although the cost of the apparatus is greater. When the temperature of the evening's milk requires to be reduced to insure its keeping overnight, as in hot weather, cold water can be employed in the same manner as hot water or steam.

It would be misleading to fix definite temperatures or assume definite rules of any kind in speaking of the broad principles and practices of British cheese-making, because there are so many systems which differ materially in important particulars.

A thermometer should be used at all times and in all systems. The old method of testing by the hand hardly now exists, and certainly not among good cheesemakers. The ordinary temperatures at which milk is set or steeped vary with the system adopted and the temperature of the atmosphere—from 80° to 90°, more or less, is the nearest indication that it is safe to make. High temperatures are used in making deep cheeses, such as Cheddars; low temperatures in making shallow cheeses, as the old-fashioned Dunlops. The Gloucester is a well-known variety set at a temperature nearer to 80° than 90° F. By setting at too high a temperature the curd gets hard and tough, though it needs a considerable amount of consistency if it is to retain a symmetrical form in a deep cheese. If worked too cold, the curd is soft and the whey difficult to get out of it, the processes of rennet fermentation and acid fermentation do not go on sufficiently, and their work is imperfect. In all cases the greatest regularity in method should be maintained from day to day.

After heating, the colouring matter (now almost invariably Annatto, q.v.) is put in. This is not considered an adulteration, as it is innocuous. It in no way improves the quality of the cheese, the effect being only upon the colour. All cheeses are not coloured, though the practice is widespread. Rennet is put in about the same time, and after thorough stirring for the purpose of mixing these added ingredients, as well as for keeping down the cream, it is left for 40 or 60 minutes.

Breaking the curd to let out the whey is the next process. Networks of thin wire, or series of thin knives, are passed through it in various directions with great caution, to prevent the curd substance being carried off with the whey, which would give it a white rather than its natural green hue. As the curd hardens it is more quickly worked and finally broken into small particles, so as to allow the whey to escape. The expulsion of the latter is helped on by the contraction of the curd, due to the gradual increase of acidity. Acidity develops naturally if time is allowed, but it is judicious to hasten it by the addition of warm whey during the process of working. Another method of bringing about the necessary amount of acidity is to expose the curd to the air for a time before it is salted. Salt, besides giving a flavour, stops the action of the acidity in cheese after it has done its work of expelling the whey. If allowed to go on, the acidity would destroy the cheese by curtailing the ripening action of rennet. Excess of salt retards the latter process.

After the curd has been broken thoroughly, on being allowed to settle so as to drain off the whey, it adheres together into an india-rubber-like mass; this is cut and broken up into small pieces by its passage through a 'curd-mill.' The finest quality of dairy salt should be used; the crystals being large is an indication of its purity, especially from magnesia salts, which give a bitter taste and otherwise injure all dairy products. The quantity employed is, more or less, about 1 lb. of salt to 56 lb. of curd dry enough to be made up and put into the cheese-press. Its amount should vary with the degree of acidity and the amount of moisture present. In some cases salt is applied wholly or in part dry, or as a brine, to the outside of the cheese after it has been so far pressed. In very rare cases salt is put into the milk before coagulation.

The curd is finally packed into a 'chesset' or press vat, which has as a temporary lining a cloth of open texture called a 'cheese-cloth.' The vat, which is a strong wooden or tinned-iron vessel with perforations in the sides and bottom to allow of the escape of any little surplus moisture, is placed in a press, and the cheese subjected gradually to a pressure of about one ton. The curd soon assumes the form in which it is to remain as a cheese. For a few days the cloths are taken off regularly and changed; the cheese being turned over each time to make it keep its shape. Ripening is the next process of importance. Deep cheeses are bandaged, and some are covered with cotton cloths (caps) made to fit tightly. They are then placed in the curing or ripening room, which should be dry, well ventilated, and maintained at an even temperature of about 70° F. There the green indigestible and insipid curd changes naturally into the sweet, mellow, nutty, and full-flavoured product cheese, which, if taken in moderation, and especially towards the end of a meal, is an aid to digestion. The ripening process, which is also associated with drying and shrinkage of about 10 per cent. in weight, varies in length from a few weeks to a few months. Acid cheeses are soon ready for market, and spoil if kept for a long time. Sweet cheeses are slow in maturing, and continue to improve even if kept for years. The tendency in cheese-making both in Great Britain and in America has recently been to early maturity, the strong inducement being that of early returns.

The Cheddar system of cheese-making, which first originated in Somersetshire, is, if we embrace Great Britain, Canada, and the United States of America, the most widely practised system of all. The old methods have been much altered in recent times to suit the tendency in the market for early maturity. The following is an account of the system as now practised, with improvements suggested by American and Canadian experience.

The cream is removed from the evening's milk after standing overnight, and is only returned to the full bulk immediately before putting in the rennet; the object is to prevent the cream being made oily by heating to a high temperature. The rennet is added at a temperature ranging from 82° to 88° F., but the milk is heated a few degrees above the point fixed upon for steeping, and left to ripen. The temperature falls to the required point meanwhile. The higher range of temperature is adopted when the milk is sweet and recently drawn from the cow. Low temperatures suit old milk or warm weather. If the cheese is to be marketed within twenty days, enough rennet should be added to induce the initial stages of coagulation within eight to twelve minutes. After this it should be left for twelve to eighteen minutes, then breaking begins with the perpendicular and horizontal cutting knives. It is stirred for about fifteen minutes with a hand-rake, and the temperature afterwards raised to 96°-98° F., or even by some up to 102° F. The whole is allowed to settle and remain nearly an hour to 'cook' the curd. As soon as the latter is elastic enough for the particles to retain their independent shapes on being grasped and squeezed by hand, the bulk of the whey is run off. What remains and the curd, still in small pieces, are removed bodily from the steep-tub or vat, and placed in a flat cooler with an inner movable, sparred, false bottom, to secure drainage. The vessel is lined with a cheese-cloth. On this the curd is exposed to the air and well worked by hand, so as to press out the whey and keep the particles from adhering to one another at too early a stage. After being well worked and exposed it is left to run together, being covered up to preserve heat. It is subsequently cut, piled, and left covered with a cloth for perhaps half an hour. The curd then smells and tastes slightly acid. It is either milled or put through Harris's stamp lever breaker, which cuts it into pieces like fingers. It is subsequently weighed, and should amount to fully 1 lb. to the gallon of milk, and is again exposed to the air to get quit of taints, and to toughen before salting, which should be done when a velvety feeling is noticeable. The salt is added dry at three separate times, and well mixed. The curd is then left to cool down to about 70° F. before being put into the vat. Pressure for about two and a half days is followed by ripening or seasoning. The whole operation of making up the curd may be over in five hours, or may take six or seven hours, according to circumstances. A good Cheddar cheese contains when ripe about 28 per cent. of casein, and nearly 34 per cent. both of butter and of moisture.

Cheshire Cheeses are manufactured in Cheshire, Staffordshire, and Shropshire. In their deep shape and also in many details of their working they resemble Cheddars. Setting is done in a square covered vat, and after making up they are often put into an oven to cook for a night before going to press. In the latter they remain for nearly a week. Derbyshire Cheeses are steeped and worked in a manner which closely corresponds to the Cheshire system. The salt, however, is applied externally. Gloucester Cheeses are made by a sweet process very much the same as the Derbyshire process. Double and Single Gloucesters are identical, with the exception of the thickness and the consequent rate at which they ripen. After a time they are scraped clean and painted with Spanish brown. Leicester Cheeses are small and flat, and made by a sweet process. They are at first lightly salted, but salt continues to be added externally. They take a long time to mature.

Stilton Cheeses are made mostly in Leicester. They used to be double cream cheeses, but are now successfully made of the milk as it comes from the cow. The curd is not subjected to pressure like that used in making the previously mentioned forms. While on the shelves ripening it is supported by a bandage, and during that time the characteristic blue mould should form throughout its substance.

Gruyère Cheese, made in the canton of Fribourg, Switzerland, is a whole-milk cheese, as are also the Dutch cheeses of Gouda and Edam. The fancy cheeses of the Continent, as Camembert, Brie, Roquefort, Limburg, Gorgonzola, &c., command a high retail price in Britain because of their perishable nature and because their consumption is restricted to a limited and wealthy class. Imitations have been made, but of a spurious and imperfect kind, owing to the impossibility of securing the secrets of their manufacture. The broad facts are known, but not the details. For example, it is quite understood that some soft cheeses are made by mixing old and new curd together. The quality of the natural pastures also affects some, notably the Parmesan cheeses from northern Italy. See the works on dairying named at BUTTER; and Harris's Cheese and Butter Maker's Handbook (1885).

AMERICAN CHEESE AND CHEESE-MAKING.—The art of cheese-making in America has undergone a radical change. Previous to the introduction of the factory system American cheese was pungent in flavour and decomposed rapidly. Consequently American cheese was not popular in foreign markets, and met with a very restricted sale. Since the factory system has been brought to a high condition of excellence, American cheese competes favourably, in even the English market, with the home- made Cheddar, Cheshire, and other popular kinds. The system practised in American factories is an improved Cheddar process, and prominent English experts have at times referred to the American system as being worthy of imitation in English dairies. Under the prevailing system the manufacture of cheese in America (the United States and Canada) increased more than 100 per cent. in 20 years, as the following figures show:

From 1880 onwards the manufacture and export of cheese from the United States decreased: thus in 1890 the total product was 95,376,053 lb., valued at 8,591,042. The Canadian product, on the other hand, increased greatly; the exports of Canadian cheese in 1893 had a value of 13,407,470. In 1893, Britain imported in all 232,675,744 lb., worth £5,160,918. The decrease in exports from the United States was due to the too prevalent adulteration of cheese with oleo-margarine and lard oils, through which the quality fell off, and an unfavourable reputation was acquired, while Canadian cheese has been kept pure. In 1897 the total export from the United States was valued at $4,636,063—little more than half of that in 1890.

The American system of cheese-making has been reduced by improved mechanism and association in the form of the factory method to the most economical point. This method of manufacture was a growth by necessity rather than a discovery. A large dairy was divided by the death of the owner, who left three sons. The sons united and manufactured their milk at the old dairy, and in time neighbours joined, and the first factory was established in 1851 under the management of the oldest of the three brothers. In course of time the business increased and became reduced to a most economical basis, while by the employment of skilful operatives the quality of the product was gradually raised. The factories were gradually enlarged until the milk of 1200 cows could be worked up in the largest, and an average factory received the milk of about 400 cows. One Canadian factory makes 216,000 lb. of cheese yearly from the milk of 1300 cows.

The curing occupies about three months, the temperature of the curing-room being kept at 65° F. Gang presses are used, in which a large number of cheeses laid on their sides are pressed at once by turning one screw. A common test by which the ripeness of the curd for pressure is determined is by touching it with a hot iron, and when long strings are drawn from the curd by the iron, the curd is ripe.

Milk is brought to the factory twice daily, and is weighed and run into the vat from the delivery window. The milk is either bought by the factory, or is worked up at a stated charge, or the factory is managed on the co-operative plan in which the net proceeds are divided periodically. Under this factory system the quality of the cheese is uniform and as high as is secured in any well-managed private dairy. About one-fifth of the cheese pro- duced in America is made in private dairies in which the same system prevails.

There are several other kinds of cheese made in both factories and private dairies, as Edam (the round Dutch cheese), a small cylindrical cheese similar to the English Wiltshire, weighing 10 to 14 lb.; a flat cheese called English dairy cheese, similar to the double Gloucester cheese and coloured as highly; a few Stilton cheese; cream cheeses for immediate use; and very good imitations of the European Limburger, Schweizer, Neufchatel, Brié, Gouda, Camembert; and some other fancy makes to supply the French, German, and other immigrant population.

The cows used in the cheese dairies in the United States and Canada are mostly 'grade' shorthorns, or native cows improved by crosses of shorthorn, Devon, Ayrshire, and Dutch breeds. Jersey and Guernsey cows, and the best of the higher bred animals, are used for the highest class of cheese of the fancy kinds. The profitable exploitation of the dairy in America has raised the value of lands suitable for grazing cows to an average value of nearly $100 (£20) per acre for the fee simple, which is twice as much as that of grain farms. The cheese-dairy business prevails mostly in the states of New York, Pennsylvania, Ohio, Iowa, and Wisconsin, and in the province of Ontario, Canada. The cows are chiefly fed upon pasturage aided in the latter part of the summer by soiling crops, of which maize is almost universally chiefly depended upon. The cheese-making season begins in April and continues until November. See X. A. Willard's Practical Dairy Husbandry (1875), L. B. Arnold's American Dairying (1877), and Henry Stewart's American Dairyman's Manual.

CHEESE-PRESS.—The most common form is the lever press. A powerful steel coil or spring is sometimes substituted for the lever. In large factories the gang press is employed to press a large number of cheeses at one time by means of a powerful horizontal screw. The old method was by placing a heavy stone (hence the name stoning cheese) on the lid of the chesset, or by hanging it by a ring fixed to its upper side from the end of a wooden beam which acted as a lever and passed over the lid of the cheese-press vat.