Why Is Rennet Controversial?

Mmmmm! HAVE YOU HAD YOUR CHYMOSIN TODAY?


Courtesy of wholefoods.com. I did not write this article.

Historically rennet was extracted from calf stomachs by killing the calves, cutting the stomach into strips, scraping the lining to remove surface fat, stretching it onto racks where moisture is removed, grinding it and then finally mixing it with a salt solution until the rennin is extracted. Today the use of animal rennin is controversial to a variety of cheese consumers. The main positions are subdivided below.

Animal rights. Animal rights activists argue that it is inhumane to kill calves for their stomach enzymes, especially when there are several alternative coagulants available to make cheese. These activists would argue that if you eat cheese, then purchase one that is made using cloned or microbial enzymes.

Vegetarianism. Vegetarians can have a confusing time trying to figure out what type of coagulant is acceptable in their cheese. While some vegetarians would strictly adhere to a non-dairy diet, others who eat dairy are content to allow microbial coagulants and some can accept cloned chymosin as a reasonable alternative to using calf rennet. Several vegetarian organizations accept the use of cloned animal enzymes as a reasonable alternative to the animal rennet derived from the killing of calves.

Bioengineering. Genetic engineering has brought new ways to create chymosin for use in cheese making. Originally, a prochymosin gene was injected into a host strain of E Coli K-12, creating a tiny enzyme factory that produced an extremely pure and recoverable chymosin for use in cheese production. Current technology cuts genes from a calf cell and injects it into the genomes of bacteria and yeast. This produces high quality chymosin that is not subject to the volatile market for animal derived rennet. It is estimated that 70% of domestic cheese is produced with bioengineered chymosin. For a consumer who does not want bioengineered foods, animal or microbial rennet should be their choice.

Religion. Some orthodox religions (Jewish and Islam) have specific requirements and prohibitions for the consumption of meat products that can preclude the use of animal rennet. For example, information received from Dr. Chaudry of the Islamic Food and Nutrition Council of America (IFNCA), stated that for a food to be "Halal" (permitted for consumption by Muslims), it must be void of certain animal products and processing procedures. In this case, cheeses that are made from animal rennet are only excluded if the calf is slaughtered improperly or is contaminated with other prohibited ingredients or procedures. The IFNCA recommends the use of microbial or bioengineered chymosin for cheese making.