Whey protein is a constituent that is left behind while making cheese from milk. Generally, cow's milk incorporates two major proteins: whey and casein. Whey protein is formed during the cheese-making process, which begins with the addition of specific enzymes to milk, causing it to break. The curds are utilized to produce cheese, with the liquid portion containing whey protein. This watery whey is then pasteurized and dried into a powder that can be used in a number of ways.