AUSTIN, TEXAS, February 23, 2001: Vegetarians have always been faced with the challenge of finding cheese made without rennet. Derived from the stomach of young calves, the enzyme rennet was at one time the only coagulant that would produce cheddar or hard cheeses. Since 1989 a bio-engineered rennet called microbial chymosin was approved by the FDA and has been used by cheese-producing companies. To animal rights activists and vegetarians this alternative is more acceptable than killing calves for rennet. Estimating that at least 70% of domestic cheese is made from bio-engineered chymosin, labeling is so poor that the consumer is left unaware of the enzyme used to produce the cheese. Companies can simply use the word “enzymes” without detailing whether the source is animal, plant, or microbial.