Yes, most Brie contains rennet. Traditional French Brie is made with animal rennet, and this remains the standard for the majority of Brie sold worldwide. However, some commercial brands use microbial or plant-based alternatives, so the answer depends on which Brie you’re buying.
Why Brie Needs Rennet
Rennet is an enzyme that causes milk to separate into solid curds and liquid whey. In Brie, this coagulation step is essential. The enzyme doesn’t just form the initial curd; residual rennet continues working during the weeks of ripening, breaking down proteins in a process that gives Brie its characteristic creamy, almost liquid texture near the rind. Without this ongoing protein breakdown, Brie would stay firm and chalky rather than developing that soft, oozy interior.
Some styles of Brie rely more heavily on acid from bacteria to set the curd rather than rennet. Brie de Melun, considered the ancestor of all Bries, is a lactic-set cheese that uses only a small amount of rennet and coagulates slowly over a long period. But even these lactic recipes are typically “rennet-assisted,” meaning a small dose of rennet still plays a role.
Traditional Brie Requires Animal Rennet
Brie de Meaux, the most famous protected-designation Brie, must be made with raw cow’s milk and animal rennet to carry its PDO label. This isn’t optional. The designation legally requires animal rennet, sourced from the stomach lining of young calves. The same applies to most artisan and French-made Bries, where animal rennet remains the standard ingredient.
Across mainland Europe, animal rennet is still the norm in cheesemaking. In the United States and England, microbial (non-animal) rennet is more commonly used across many cheese types, which means American-made Brie is more likely to use a vegetarian-friendly enzyme. But “more likely” is not a guarantee, and you’ll need to check the label.
How to Tell Which Rennet Your Brie Uses
Cheese labels don’t always make this easy. The word “enzymes” in an ingredient list tells you almost nothing, since it could refer to animal, microbial, or genetically engineered sources. Here’s what to look for:
- Rennet or animal enzymes: This means animal-derived rennet, typically from calf stomach lining.
- Vegetable rennet: Derived from a plant source, such as thistle flowers. Vegetarian-friendly.
- Microbial rennet or microbial enzymes: Produced by fungi or bacteria. Also vegetarian-friendly.
- Fermentation-produced chymosin (FPC): Sometimes labeled as “vegetarian rennet.” This is made by genetically modified microbes that produce the same enzyme found in calf rennet but without any animal involvement.
- Non-animal enzymes: A catch-all term confirming the rennet isn’t animal-derived.
If the label simply says “enzymes” with no qualifier, assume animal rennet unless the packaging explicitly states “suitable for vegetarians.” Some brands list different ingredient details depending on the country of sale, so even the same product can be labeled differently in different markets.
Vegetarian Brie Options
Vegetarian Brie exists but takes more effort to find. Budget retailers like Aldi have carried vegetarian Brie, and some specialty brands market themselves specifically to vegetarian consumers. The key is that any Brie using microbial, plant-based, or fermentation-produced rennet qualifies.
Fresh cheeses (cream cheese, ricotta, mozzarella in some cases) generally don’t use rennet at all, relying on acid to coagulate the milk. But Brie is a ripened cheese, and ripened cheeses almost always require some form of rennet to develop their texture. If a Brie doesn’t specify “vegetable rennet” or “microbial enzymes” on the label, it very likely contains animal rennet.
Rennet and Kosher or Halal Certification
For kosher cheese, the rennet source is only part of the equation. Even if a Brie uses microbial or plant-based rennet, it may still not qualify as kosher. Jewish dietary law historically prohibited cheese made by non-Jewish producers, a rule that many certification agencies still enforce. In practice, this means a kosher-certified cheese requires not just acceptable rennet but also the physical presence of a kosher supervisor during production, who personally adds or activates the rennet for each batch.
The amount of rennet in cheese is tiny, far less than one part in sixty. But because rennet is the ingredient that gives cheese its form, it cannot be considered negligible under kosher law regardless of how little is used. This makes kosher-certified Brie relatively rare and typically more expensive.
For halal certification, the concern is similar: animal rennet from a calf that wasn’t slaughtered according to Islamic guidelines would make the cheese non-halal. Brie made with microbial or plant-based rennet avoids this issue entirely, making those versions suitable for halal diets even without formal certification.