Shocking truth: 90% of all traditional cheeses are animal-based!

By pharmacist, Dr. in Chemistry Alisa Palatronis | September 22, 2021 | 8:45 min read

Vegetarians and almost vegans use to cook and order meals with cheese. Pizzas, pastas, cheese-stuffed dumplings, cookies with cheese, cheese sticks, cheese&wine… the list may be endless. Who have ever knew that most of traditional cheeses are made with animal-based product – rennet?

In our previous articles, we have already talked about cheeses:

Are you fertile on keto?

Casein in dairy

Vegetarians and so-called almost vegans allow cheese in their daily food lead by the belief that it is a cruelty-free choise.

Lacto-vegetarians follow a diet that removes all animal flesh (meat and fish), but allow dairy products, while lacto-ovo vegetarians allow both dairy and eggs. Almost vegans (especially health vegans if comparing with ethical or environmental vegans) follow a diet which consists of plant-based ingredients, but may allow honey or dairy time to time, however, not on a daily basis.

What is rennet?

Rennet is made of a complex of enzymes. It produces naturally in a stomach of young ruminant animals (cow, sheep, goat, and pigs) to curdle mother’s milk for easier digestion. Rennet consists of a specific enzyme chymosin and other enzymes (pepsin, lipase). The amount of rennet secretion in young ruminant animals decreases with their age, as rennet produces naturally only during their feeding period.

Cow Triptych (Cow Going Abstract), 1982, Roy Lichtenstein, image source:

Is rennet vegetarian?

Rennet stands as an animal by-product after baby animals are killed for meat production. Rennet is obtained from the fourth stomach of unweaned baby calves, lambs, and goats. Rennet is not considered vegetarian, because it is obtained after slaughtering the animal.

What is rennet in cheese making?

animal rennet

In most cheese making recipes, rennet is a key component of the process.

Rennet is used for milk coagulation (in other words, to separate milk into solid curds and liquid whey).

image source: wikipedia

Rennet is added to milk after milk is ripened with special bacterial cultures like strains of Lactococcus, so-called “starters”. This is a basis of cheese making around the world, in Europe, US and many other countries.

The texture and flavor of different types of cheeses vary depending on milk type, bacterial cultures for starters, and technological steps used for cheese ripening.

For example, for Swiss and Italian cheeses, calf rennet is destroyed by high cooking temperatures during the cheese making process (anyway, it is used at the beginning of cheese making). However in Cheddar cheese, a significant amount of rennet survives and participates in further ripening stages to yield desirable texture and flavor.

What cheeses aren’t vegetarian?

Cheese types which consist animal rennet aren’t vegetarian. This includes variety of loved cheese types: mold and bacterial ripened cheeses. All of them are traditionally coagulated by rennet. Examples:

1. Mold ripened cheeses

  • Blue, Danablu, Gorgonzola, Roquefort, Stilton, Brie, Camembert, Carre del Est

2. Bacterial ripening

Extra hard cheeses

  • Grana Padano, Parmesan, Asiago, Sbrinz

Hard cheeses

  • Cheddar, Cheshire, Graviera, Ras

Semi-hard cheeses

  • Caerphilly, Mahon, Monterey Jack
  • Pasta filata
  • Mozzarella, Kashkaval, Provolone, Traditional goat cheeses

Highly salted cheeses

  • Domiati, Feta, Bryndza

Cheeses with eyes

  • Swiss Type – Emmental, Gruyer, Massadam, Dutch type – Edam, Gouda

3. Other bacterial ripened cheeses

  • Brick, Havarti, Limburger, Muenster, Port du Salut, Trappist, Teleggio, Tilsit

Vegetarian-friendly alternatives for rennet

Vegetarianism, veganism or kosher lifestyles call for alternatives to animal rennet. In cheese making, there are several alternatives for animal rennet, which allow to acquire “vegetable rennet”.

Vegetarian alternatives for rennet:

  • Natural coagulants like vinegar and lemon juice
  • Specific plants (thistle, artichoke, nettle and mallow). Image source:
  • Microbial rennet” acquired from mold. Examples:  Miehei coagulant (R. miehei proteinase), Pusillus coagulant (R. pusillus proteinase), and Parasitica coagulant (C. parasitica proteinase)
  • Enzymes which break down some proteins and amino acids. Examples: aspartyl (acid) proteinases
  • Genetically engineered rennet, for example, the gene for calf chymosin – rennet enzyme – has been cloned in several micro-organisms. To be precise, the origin of genetically engineered rennet is always animal rennet, though the obtained rennet was never in the stomach of an animal but rather produced in a lab.

What cheeses are vegetarian friendly?

Always look for cheeses marked “vegetarian” or “kosher” to ensure that you are avoiding rennet of animal origin.

Unripened, acid coagulated cheeses have no animal-based rennet. For unripened cheeses, milk coagulation is reached by using ambient, hot or condense/crystallize coagulation. Very fresh, fragile curd cheeses can be made without animal rennet. These cheese types are vegetarian friendly.

Rennet-free cheeses

  • Baker’s
  • Cottage cheese
  • Cream cheese
  • Neufchatel
  • Quark
  • Queso Blanco
  • Indian cheese Paneer which has a firm structure
  • Ricotta
  • Gjetost
  • Mysost
  • Labneh. It is a soft Middle Eastern cheese made from strained yogurt
  • Some British and other modern goat cheese could be vegetarian (check the label!)
  • Tofu cheese
  • Vegan cheeses
  • Provolone
  • Some young mozzarellas (check the label!)
  • Mascarpone (heated heavy cream thickened by lemon juice)

Check our delicious recipe with Paneer cheese Sautéed Brussels Sprouts with Paneer Cheese!

Sautéed Brussels Sprouts with Paneer Cheese

For detailed list of rennet-free cheese brands, check the list The 2021 List of Vegetarian Cheeses and Brands arranged by


  1. CHEESE | Cheese in the Marketplace. R.C. Chandan. Encyclopedia of Food Microbiology (Second Edition), 2014, Pages 384-394,
  2. Dairy – Fermented Products. R.C. Chandan. Global Technologies, Inc., Minneapolis, Minnesota, USA, Food Processing: Principles and Applications, Second Edition, 2014. Published by John Wiley & Sons, Ltd.
  3. P.F. Fox, T.M. Cogan, in Cheese: Chemistry, Physics and Microbiology, 2004, link:
  4. Diversity and Classification of Cheese Varieties: An Overview. Paul L.H. McSweeney, … Patrick F. Fox, in Cheese (Fourth Edition), 2017, link:
  5. Do Vegetarians Eat Cheese: The Ins + Outs of Vegetarianism by Meredith James  December 29, 2020 on TofuBud, link:


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