Prepared from the curd precipitated from milk by rennet (containing the enzyme chymosin or rennin), purified chymosin, or lactic acid. Cheeses other than cottage and cream cheeses are cured by being left to mature with salt, under various conditions that produce the characteristic flavour of each type of cheese. Although most cheeses are made from cow's milk, goat's and sheep's milk are used to make speciality cheeses, which are generally soft.
There are numerous variants (over 400) including more than 100 from England and Wales alone (nine major regional cheeses: Caerphilly, Derby, Double Gloucester, Cheddar, Lancashire, Red Leicester, Stilton, and Wensleydale). Some varieties are regional specialities, and legally may only be made in a defined geographical area; others are defined by the process rather than the region of production. The strength of flavour of cheese increases as it ages; mild or mellow cheeses are younger, and less strongly flavoured, than mature or extra-mature cheeses.
Cheeses differ in their water and fat content and hence their nutrient and energy content, ranging from 50-80% water in soft cheeses (mozarella, quark, boursin, cottage) to less than 20% in hard cheese (Parmesan, Emmental, Gruyère, Cheddar) with semi-hard cheeses around 40% water (Caerphilly, Gouda, Edam, Stilton). They retain much of the calcium of the milk and many contain a relatively large amount of sodium from the added salt. Blue-veined cheeses (Gorgonzola, Stilton, Roquefort, etc.) derive the colour (and flavour) from the growth of the mould Penicillium roquefortii, during ripening. Holes (e.g. in Gouda, Gruyère) arise during ripening from gases produced by bacteria.
Traditionally, hard cheeses must contain not less than 40% fat on a dry weight basis, and the fat must be milk fat. However, a number of low-fat variants of traditional hard cheeses are now made. A 40-g portion of hard cheese is a rich source of vitamin B12 and calcium; a good source of protein and vitamin A; a source of vitamin B2, iodine, and selenium; depending on type contains 9-16 g of fat, of which 64-69% is saturated; provides 120-190 kcal (500-800 kJ).
Cottage cheese is soft, uncured, white cheese made from pasteurized skim milk (or milk powder) by lactic acid starter (with or without added rennet), heated, washed, and drained (salt may be added). Contains more than 80% water. Also known as pot cheese, schmierkäse and, in the USA, as Dutch cheese. A 50-g portion is a source of protein and supplies 50 kcal (210 kJ).
Baker's or hoop cheese is made in the same way as cottage cheese, but the curd is not washed, and it is drained in bags, giving it a finer grain. It contains more water and acid than cottage cheese.
Cream cheese is unripened soft cheese made from cream with varying fat content (20-25% fat or 50-55% fat); at 50% fat a 100-g portion is a rich source of vitamins B12 and A and supplies 440 kcal (1800 kJ).
Processed cheese (first developed by J. L. Kraft & Co. in Chicago, 1915) is made by milling various hard cheeses with emulsifying salts (phosphates and citrates), whey, and water, and pasteurizing to extend the shelf life of the cheese. Typically 40% water, a 30-g portion contains 5 g of protein and 8 g of fat, and provides 100 kcal (410 kJ). A soft version with 50% water is used as a spread.
Feta is Greek and general Balkan; white, soft, crumbly, salted cheese made from goat's or ewe's milk.
Swiss cheese is an American name for any hard cheese that contains relatively large bubbles of air, such as the Swiss Emmentaler and Gruyère cheeses.
