Rennet: Meat and Milk?


I’ve always understood that a lot of cheese is not kosher because it contains animal rennet, which constitutes a mixture of milk and meat. Kosher cheese substitutes enzymes. But in recent years, I have found a lot of certified kosher cheese on the market that lists “rennet” as an ingredient. In fact, some of it even says “animal rennet.” This is all while these products are certified by some of the most recognized hechsherim. How is it possible that cheese containing animal rennet is really kosher?



  1. Rennet is made from the lining membrane of a stomach or one of its compartments (as the fourth of a ruminant) used for curdling milk. In order for Rennet to be Kosher it must be made from either a synthetic material (vegetarian cheese) or from the stomach of a Kosher animal. Once the rennet has been manufactured it is no longer considered to be meat and it can be used in the manufacture of cheese. Many Kashrut organizations prefer to use synthetic material but some do use rennet sourced from a Kosher animal.

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