Believed to have originated in Asia in the second or third millennium BC, cheese was probably discovered accidentally by nomads who stored ewes’ or goats’ milk in bags made from sheeps’ or goats’ stomachs. Bacteria and enzymes in the stomach lining and warmth combined to produce a soft curd, which was a simple cheese. In time, the process was so refined that it could be controlled and reproduced, and knowledge of it spread from Asia to Europe.
The Romans introduced cheesemaking to Britain during the first century BC or AD. Today, there are about 400 different cheeses with more than 800 names. Cheese is usually made from cows’ milk, but it is also made from the milk of sheep, goats, camels, reindeer, buffaloes and horses. Many of these cheeses are consumed only in the region where they are made, but others are nationally and internally marketed. One such cheese is Greek feta, a soft, mild flavored, white cheese made from ewes’ or goats’ milk. Some cheeses are made by combining the milk from several different animals.
Types of Cheese
Cheesemakers divide natural cheeses into about 20 groups, according to texture (hard, medium or soft) and flavor (mild, medium or sharp). Feta, ricotta and cottage cheese are soft and mild, Brie and Camembert are soft, ripe cheeses with a medium flavor. Hard cheeses with a medium sharp flavor are Gruyere and Emmenthal.
Parmesan is a hard, sharp cheese, and Cheddar is a hard cheese with a mild-sharp flavor. The texture and flavor of all types of cheese may vary according to the region in which they are made.
Processed cheese is a blend of natural cheeses that is specially treated during processing to ensure a mild, uniform flavor and enhance its keeping qualities.
Methods of making natural cheese vary according to the type of cheese, but the basic processes are similar. Processing begins with the delivery of fresh milk to the manufacturer. About 10 kg milk is required to make 1 kg hard cheese. In order to separate the curd (milk solids) from the whey (liquids), a lactic acid starter bacteria is added to the milk in a large vat; automatic paddles stir the milk to distribute the starter. The bacteria begin the ripening or fermentation process, and the milk gradually thickens. Rennet extract (an enzyme that is extracted from the fourth stomach of calves) is added as a curdling agent, and the milk is stirred for about 3 minutes until it coagulates into a soft, semi-solid mass known as the curd.
The curd is cut into cubes, approximately 6 mm square, to facilitate the separation of whey from curd. The curd is heated to about 40°C and stirred again to remove any remaining whey and produce the correct degree of acidity and firmness. In a process called ditching, the curd is then pushed to the sides of the vat, leaving a ditch in the center into which any remaining whey will drain. The curd is turned several times to complete the draining process and cut into blocks, 8 to 10 cm long and 15 cm thick. The blocks are salted and pressed into shape in molds, which are stacked and kept under pressure for about 12 hours. The cheese is then stored in controlled temperature curing rooms for a period varying from a few days up to 2 years. Soft cheeses undergo a short curing process, whereas sharp cheeses with a hard, crumbly texture are cured for long periods.
Differences in flavor and texture are achieved by varying the type of milk, amount of salt, processing temperatures and amount of whey removed. Some cheeses, such as Danish Blue and Stilton, have special bacteria cultures added during processing, and these grow during the ripening period and form distinctive blue veins throughout the cheese.
Flavorings of seeds, herbs, nuts, pepper and wine are added to some cheeses in the final processing stages. Cheese is classed as a complete protein food and is also a valuable source of fat, vitamins, calcium and phosphorus.