The Wonderful World of Cheese!
Cheese is a nutritious dairy product usually made from the curd of milk. Since it was first made some 3,000+ years ago, cheese has been an important food in the diet of many peoples. Cheese was one of the earliest foods to be prepared, by virtue of its easy manufacture and concentrated nature. The coagulation of milk is brought about naturally by a bacterium, or can be artificially induced by acids or by "rennet", a soluble substance of complex chemical nature found in the fourth stomach of the calf.
In addition to being both tasty and nutritious, cheese is an excellent way of using and preserving surplus milk from many kinds of animals. Many cheeses of Europe and Asia are made from the milk of goats and sheep, but most American cheeses are produced from cow's milk.
Cheese contains about the same amounts of protein, minerals, vitamins, and other nutrients as the milk from which it is made. Although the amount of nutrients varies according to the kind of cheese, all cheeses are relatively rich in protein and calcium.
Cheese is made from the fat and casein, a protein substance, from milk. First of all lactic acid and rennet (a substance taken from the stomach of a calf) are added to the milk. This curdles the milk and makes the fat and casein stick together. The water, or whey, is poured off, and what is left is pressed together and left to ripen.
How is cheese made?
There are many variations in cheesemaking. Although some procedures are carefully guarded secrets, the method of making cheddar is well known, especially in the United States, where cheddar is by far the most popular cheese.
Cheddar cheese is usually made from whole, pasteurized cow's milk. After being cooled to a temperature of about 87° F (31° C) the milk is poured into a large cheese vat, and a culture of bacteria, or starter, is added. The milk is then stirred for about an hour until it ripens, or attains a desired degree of acidity. Ripening is important for the rate of curdling, or coagulation, and for the final calcium content, moisture, and flavor of the cheese.
After the milk is ripe, rennet, a curdling agent extracted from a mammalian stomach. Milk must be ripened before the rennet will act, and this is often hastened by adding a "starter" of sour milk, which aids in the formation of lactic acid.
Rennet is extremely active, 1 part being said to coagulate 3 million parts of milk. It is most active at body temperature (98° F), and temperature must be most carefully controlled during the process of cheese-making.
Rennet is not used for ordinary sour-milk cheese made at home: the protein is coagulated by acid produced by bacteria from the milk-sugar. This is so, too, for 'Gervais' and other commercial lactic cheeses. But most cheeses are made with both souring and rennet: the latter being used to clot the slightly acid milk.
As the milk curdles it forms a semisolid mat that is composed of the curd, or solid protein portion of the milk, and the whey, or watery portion. The whole is beaten while still warm to break the chunks of curd into smaller pieces, and then transferred to cloths, and squeezed in a press to separate the whey. To drain even more whey, the cubes of curd are then slowly heated to about 100° F (38° C) while being stirred carefully to avoid breaking them up.
The extracted whey is not removed immediately from the vats but is allowed to remain in contact with the curd until the whey acid has time to act on and change the character of the curd protein. When the protein is sufficiently altered, the whey is drawn off and a procedure called cheddaring is begun.
In cheddaring, the cubes of curd are packed, or matted, together and then cut into slabs about 5 to 6 inches (12-15 cm) wide. The slabs are turned frequently and piled on top of each other to express even more whey. During this process, the texture of the curd becomes less rubbery and more velvety.
The cheddared curd is milled, or finely separated, into uniform-sized particles that can be evenly salted and easily placed into molds, or cloth-lined metal hoops, for pressing. Cheeses may be pressed for periods ranging from 12 to 24 hours. Soft cheeses may be pressed only by their own weight for relatively short periods. In fairly hard cheeses, however, pressing takes longer and may require additional weight on the molds.
After the cheese is pressed, it is, removed from the mold and dried for several days. It is then dipped in wax, packed into boxes, and sent to a warehouse to ripen, or cure, for three months or longer. Cheeses are cured in rooms where the temperature, humidity, and ventilation are carefully controlled. As the cheeses ripen, some of the moisture evaporates and their texture changes, probably because of protein changes. When a cheese reaches the desired final texture, it is fully ripe and ready to be sold.
There are many kinds of cheeses, some hard, some soft, some creamy, and how they turn out depends on how they are made, how much water is left in, and how they are cured.
There are more than 400 different names applied to cheeses produced in different countries or in specific regions of any country. Many of these cheeses are quite similar and differ chiefly in size, shape, or place of origin. Roquefort, for example, is like many blue-veined cheeses made in Italy and England, but only cheese made in the Roquefort area of France can legally be called Roquefort. Some kinds of cheese are known by several different names.
Because of the wide variety of cheeses, there are many ways of classifying cheeses produced today. Some useful systems are based on the final texture of the cheese, such as soft or hard, on variations in ingredients, and on methods of production. Softness or hardness is determined by the moisture content of the finished cheese. Very hard, or grating, cheeses such as Parmesan and Romano have about 30 percent moisture. Hard cheeses, such as cheddar and Swiss, have about 38 percent moisture. Semisoft cheeses, such as Roquefort and Münster, have about 45 percent moisture. Soft cheeses, which include such varieties as cream cheese and ricotta, have from 50 to 80 percent moisture.
Variations in ingredients include the kind of milk used, such as milk from cows, goats, ewes, and other mammals, and whether the milk is whole, skimmed, or enriched by additional cream. Other major differences depend on whether the cheese is ripened and the type of bacteria, mold, or other ripening agent that is allowed to develop or is added during production. Using this or various other systems, most experts believe there are only about 18 basic kinds of cheese.
- People, Places and Things, Volume 3, The Waverley Book Company Limited, 1954
- Merit Students Encyclopedia, Volume 4, P.F. Collier Inc, 1979. Page 350.
- 365 Things To Know, The Hamlyn Publishing Group, 1968. Page 94.
- The New International Illustrated Encyclopaedia, Volume 2, 1954. Page 91.