21. COMPOSITION OF CHEESE.--Since cheese is a product of milk, it is somewhat similar to milk in composition, but the change that occurs in the formation of cheese causes some differences. Nearly all the water present in milk is removed during the manufacture of cheese, so that this product becomes a concentrated food made up of all the nourishment that milk contains except small amounts of albumin, milk sugar, and mineral matter. These, because they are in solution in the water, are lost when the whey is separated from the curd. The food substances that occur in the largest amounts are fat and protein in the form of casein, which is the tissue-building material of milk. Cheese made from milk that contains some cream has in it a greater amount of fat than that made from completely skimmed milk. Besides these two chief food substances, cheese contains a small amount of milk sugar, mineral matter, and water.
22. On account of the large quantity of protein found in cheese, this food can readily take the place of meat in the diet; in fact, it has some decided advantages over meat. As has been pointed out, cheese yields more than twice as much food value as an equal weight of beef. Then, too, the buying and care of cheese are much simpler matters than the buying and care of meat. As it does not require the low temperature that meat requires and does not spoil so readily, it can be bought in considerable quantity and used as desired without danger of spoiling and loss. In addition, the use of cheese as food does not require so much skill in preparation as meat does, nor is there loss of flavor and nutriment in its preparation, as is often the case with meat.
23. QUALITY OF CHEESE.--Every variety of cheese has its own standard and quality, some being hard and dry, others moist, and still others very soft. The difference in quality is due to the way in which the curd is coagulated, the amount of pressure that is put on it, and the ripening of the cheese. The holes that often occur in cheese and give it a porous appearance are formed by gas, which is the product of the growth of bacteria. A large number of very small holes in cheese indicate that the milk used to make it was not clean and contained many kinds of bacteria. This condition could be overcome by the use of absolutely clean milk; indeed, milk of this kind is as necessary for the production of good cheese as it is for the making of good butter. Certain cheeses, such as Limburger and Roquefort, have a typical odor and flavor, the odor being due to bacteria and the flavor to mold. These are carefully grown and introduced into the cheese during its manufacture.
24. CARE OF CHEESE.--The very strong odor and flavor that characterize cheese make it necessary that care be given to cheese in the home in order to prevent it from coming in contact with other foods and transmitting its odor and flavor to them. The best place to keep cheese, particularly the soft varieties, is in the refrigerator, where it should be placed in a closed receptacle and kept as far as possible from foods that are easily tainted. It is well to avoid a damp place for the keeping of cheese, as mold frequently develops on the outside when too much moisture is present; but in case mold does appear it can be removed by cutting a thin slice from the side on which it has grown. On the other hand, cheese that is kept in a dry place becomes hard and dry unless it is wrapped in oiled paper or a damp cloth. However, such cheese need not be thrown away, for there are numerous uses, particularly in cooking, to which it can be put.
KINDS OF CHEESE
CLASSIFICATION OF VARIETIES
25. The cheese used in the United States may be included under two leading classes, namely, foreign cheese and domestic cheese. Since the foreign cheeses are imported, they are more expensive than the cheeses made here, and should not be bought if cheese is to be used as an economical article of food. They are valuable chiefly for their flavor and are generally bought for this reason. The domestic cheeses can be used in larger quantities, for, besides being less expensive, they are usually of a milder type and are more easily digested. To enable the housewife to become familiar with the principal varieties of each of these classes, a discussion of them, including their names, characteristics, and, in some cases, their use and the method of making, is here given. In addition, there are shown in colors, in Fig. 4, a large number of cheeses, together with a print of butter o, which serves to illustrate the irregular surface that is exposed when good butter is broken apart.