Think all cheese is vegetarian? Think again.

If you’ve ever dabbled in vegetarianism, the cheese platter has probably saved you from a meat-filled spread. Or, at a meat-laden restaurant, while your dining partners might go for the steak or roast chicken, you opt for the cheese-covered pasta. Rich and satisfying, cheese easily rivals carnivorous options. But if you think cheese is automatically the vegetarian alternative, think again.

Grab some cheese and read the ingredients and you might see, right there after milk, rennet. Rennet is a mixture of enzymes that act as a coagulant. It clumps the milk’s casein proteins together so that curds and whey can separate, an essential step in the cheesemaking process. Your cheese label might specify animal rennet or microbial rennet—and it’s specifically the animal rennet that doesn’t quite qualify as vegetarian.

Animal Rennet

Animal rennet comes from the fourth stomach of a ruminant animal. After a young calf, for example, drinks milk, enzymes like chymosin and pepsin in the fourth stomach work to separate the lactose, whey, and minerals from the curd. Those nutrients can then be digested more quickly than the casein and fat. Traditionally, animal rennet comes from washing and drying the fourth stomach obtained from calves. It’s then turned into a solution that can be added to milk.

Procuring the organ is a byproduct of meat production; the animal generally isn’t killed for its stomach alone. While making use of it can be seen as resourceful from a nose-to-tail standpoint, that sourcing can violate the ethics of eaters distancing themselves from the meat industry.

Using animal rennet has the draw of following traditional practices, and, according to some cheesemakers, it avoids the bitterness that can come from alternative coagulants, especially in the case of aged cheeses.

Animal rennet remains the coagulant of choice for many Old World cheeses, including Comté, Époisses, Manchego, Parmigiano Reggiano, and Roquefort. It also finds a use in many American cheeses. That means that if you’re a staunch vegetarian, or if you’re making a spread for a group of mixed eaters, you’ll do well to read the label.

But never fear, there’s no need to swear off cheese forever.

Évora PDO, a cheese made with thistle rennet

Alternative Rennet

Thanks to coagulants like microbial rennet and vegetable rennet, your cheese obsession can continue.

Made in a lab, microbial rennet is made from mold strains that contain chymosin. It’s commonly found in soft, young cheeses, since it can develop a bitterness with age. Alternately, vegetable rennet is derived from plants like nettles, fig leaves, and thistle, which are steeped into a liquid extract that can be added to milk. Thistle-rennet in particular lends a distinct flavor: It’s traditionally used in Spain’s Torta Del Casar, a spoonable sheep’s milk cheese to which it adds a sour, bitter bite.

Cornish Kern

How to Shop

If you’re unsure as to whether a cheese contains sneaky, unwanted animal ingredients, follow the trusty adage: Ask your monger. They’ll be able to guide you through your options and advise you on cheeses that will fit your, or your guests’, dietary needs.

Shopping online? While you won’t necessarily get a chance to converse with an expert, it’s easy to figure out your options. Online retailers like Murray’s and DiBruno Brothers allow you to filter cheeses by rennet type. Simply unclick animal rennet from your search results and there’s a world of vegetarian-friendly cheese still at your fingertips.

Point Reyes Original Blue

Try These

In a pinch? Try these vegetarian-friendly cheese recommendations to make selecting your spread a little easier.

Blue: Point Reyes Original Blue
Chèvre: Goat Lady Dairy Smokey Mt. Round
Washed-Rind: Cricket Creek Tobasi
Bloomy-Rind: Fromager D’Affinois
Hard: Sartori SarVecchio

Bettina Makalintal

Bettina Makalintal is culture's former editorial assistant. With a background in the food industry and as a bike mechanic, she can often be found biking in search of new donut shops.