MYTH: Cheese contains rennet from PIGS.
Does animal rennet for cheese come from PIGS?
NO. Animal rennet must come from the same species of animal as the milk being used in for cheese. Calf-rennet is used to produce cows milk cheese, lamb-rennet produces sheep milk cheese, and kid-rennet to produces goats milk cheese. Each type of animal produces a unique type of rennet to curdle the milk produced by that species. Kid-rennet will not curdle cows milk or turn it into cheese. Rennet or digestion enzymes from other animals, like swine-pepsin, are not used in cheese production.
What is Rennet?
ANIMAL RENNET is a natural complex of enzymes produced in the stomachs of nursing calves (young cows or buffalo), lambs, and kids (young goats), as well as other mammalian (milk producing) animals such as moose, camel and deer. The enzyme chymosin (rennin) found in rennet makes mothers' milk digestible for the young, turning it into a cheese-like substance.
As mentioned above, animal rennet must come from the stomach of a nursing (milk-fed) calf, kid or lamb—depending on the milk used to make the cheese. For this reason, Muslims who insist on zabihah may choose to avoid cheeses made with animal rennet. Cheeses made using animal rennet are not kosher cheeses, due to the kashrut prohibition against mixing meat and dairy products in the same meal.
GM RENNET ("Chymostar™") is a type of rennet produced by genetically modified mold (mucor miehei) or bacteria (e. coli, asperigillus niger var awamori or k. lacti). Rennet-producing DNA from a calf is introduced into the microbe's DNA so that it produces rennet identical to that which a calf produces.
Because calf rennet is produced by the microbes, animals are not slaughtered in the production process. Genetically modified rennet is safe for Muslims who insist on zabihah. GM rennet is used extensively (75%-80%) in the commercial cheese production.
VEGETABLE RENNET is a microbial rennet extracted from mold (usually mucor miehei). It has no animal origin. This is the rennet used by those who do not want to use any animal products in their cheese other than the milk. This will pass as vegetarian. Vegetable rennet is found in Kosher cheeses.