Rennet decides whether a cheese is vegetarian. Traditional rennet is extracted from the stomachs of slaughtered calves; microbial coagulants and fermentation-produced chymosin (FPC) do the same job with no slaughter. The finished cheese label often says only enzymes or rennet, so vegetarian certification traces the coagulant to its source for every cheese and whey ingredient.
What it means for each mark
- VegetarianAnimal rennet is excluded; microbial coagulants and FPC pass — the coagulant's identity is documented per cheese and whey ingredient.
- VeganAll cheese and whey ingredients are dairy-derived and outside vegan claims regardless of the coagulant used.
Where it typically hides
- Cheese labeled only with the word enzymes
- Whey and whey derivatives (the coagulant question travels upstream)
- Cheese powders in snacks, crackers and seasoning blends
- Protected-name cheeses whose specifications mandate animal rennet (e.g., Parmigiano Reggiano)
What a certification review asks for
- The coagulant identity for every cheese and whey ingredient — animal, microbial or FPC
- Attention to protected-designation cheeses whose published specifications require calf rennet
- Supplier statements for cheese powders and cheese-flavored seasonings
Alternatives
- Microbial coagulants (e.g., from Rhizomucor miehei)
- Fermentation-produced chymosin (FPC)
- Plant coagulants such as cardoon thistle, used in some traditional cheeses
Frequently asked questions
What does enzymes mean on a cheese label?
It usually refers to the coagulant, which may be animal rennet, a microbial coagulant or fermentation-produced chymosin. The label rarely distinguishes them; the cheesemaker's documentation does.
Is Parmesan vegetarian?
Parmigiano Reggiano is not: its protected specification requires calf rennet. Hard cheeses of a similar style made with microbial coagulants exist under other names.
Is fermentation-produced chymosin vegetarian?
Yes. FPC is made by microorganisms carrying the chymosin gene; no animal tissue is used in production, and vegetarian standards accept it.