Cheese is a food made from milk, usually the milk of cows, buffalo, goats, or sheep, by coagulation. The milk is acidified, typically with a bacterial culture, then the addition of the enzyme rennet or a substitute (e.g. acetic acid or vinegar) causes coagulation, to give "curds and whey".Some cheeses also have molds, either on the outer rind (similar to a fruit peel) or throughout.
Hundreds of types of cheese are produced. Their different styles, textures and flavors depend on the origin of the milk (including the animal's diet), whether it has been pasteurized, butterfat content, the species of bacteria and mold, and the processing including the length of aging. Herbs, spices, or wood smoke may be used as flavoring agents. The yellow to red color of many cheeses is a result of adding annatto. Cheeses are eaten both on their own and cooked in various dishes; most cheeses melt when heated.
For a few cheeses, the milk is curdled by adding acids such as vinegar or lemon juice. Most cheeses are acidified to a lesser degree by bacteria, which turn milk sugars into lactic acid, then the addition of rennet completes the curdling. Vegetarian alternatives to rennet are available; most are produced by fermentation of the fungus Mucor miehei, but others have been extracted from various species of the Cynara thistle family.
Cheese has served as a hedge against famine and is a good travel food. It is valuable for its portability, long life, and high content of fat, protein, calcium, and phosphorus. Cheese is more compact and has a longer shelf life than the milk from which it is made. Cheesemakers near a dairy region may benefit from fresher, lower-priced milk, and lower shipping costs. The long storage life of cheese allows selling it when markets are more favorable.
The origin of the word cheese appears to be the Latin caseus, from which the modern word casein is closely derived. The earliest source is probably from the proto-Indo-European root *kwat-, which means "to ferment, become sour".
In the English language, the modern word cheese comes from chese (in Middle English) and cÄ«ese or cÄse (in Old English). Similar words are shared by other West Germanic languages â West Frisian tsiis, Dutch kaas, German KÃ¤se, Old High German chÄsi â all of which probably come from the reconstructed West-Germanic root *kasjus, which in turn is an early borrowing from Latin.
The Latin word caseus is also the source from which are derived the Spanish queso, Portuguese queijo, Malay/Indonesian Language keju (a borrowing from the Portuguese word queijo), Romanian caÅ and Italian cacio.
When the Romans began to make hard cheeses for their legionaries' supplies, a new word started to be used: formaticum, from caseus formatus, or "molded cheese" (as in "formed", not "moulded"). It is from this word that we get the French fromage, Italian formaggio, Catalan formatge, Breton fourmaj and ProvenÃ§al furmo. Cheese itself is occasionally employed in a sense that means "molded" or "formed". Head cheese uses the word in this sense