Whey cheeses are a dairy product made not from whole milk, but from the whey remaining after cheese production. Whey or milk plasma is the liquid remaining after milk has been curdled and strained; it is a by-product of the manufacture of cheese or casein and has several commercial uses. Sweet whey is manufactured during the making of rennet types of hard cheese like Cheddar or Swiss cheese. Acid whey (also known as sour whey) is obtained during the making of acid types of cheese such as cottage cheese. Whey is used to produce ricotta, brown cheeses, MessmÃ¶r/Prim and many other products for human consumption. It is also an additive in many processed foods, including breads, crackers and commercial pastry, and in animal feed. Whey proteins primarily consist of a-lactalbumin and ÃŸ-lactoglobulin. Depending on the method of manufacture, whey may also contain glycomacropeptides (GMP). Whey protein (derived from whey) is often sold as a nutritional supplement. Such supplements are especially popular in the sport of bodybuilding. In Switzerland, where cheese production is an important industry, whey is used as the basis for a carbonated soft drink called Rivella.