What Kinds of Cheese Are Not Vegetarian?

While many assume all cheese is vegetarian, a surprisingly large number of traditional varieties are not vegetarian due to a key ingredient. The reason lies in the use of animal-derived rennet, an enzyme sourced from the stomach of young ruminants, during the cheesemaking process, particularly for hard, aged cheeses.

Quick Summary

Traditional cheeses like Parmesan, Pecorino Romano, and Gruyère use animal rennet and are not vegetarian. Vegetarians must learn to read labels and seek microbial or plant-based alternatives.

Key Points

• Animal Rennet is the Cause: Many cheeses are not vegetarian because they contain animal rennet, an enzyme from the stomachs of young ruminant animals.

• Not All Cheeses Are Equal: While soft cheeses like ricotta and paneer are typically rennet-free, hard and aged cheeses are often made with animal rennet.

• Authentic Parmesan is Never Vegetarian: To be certified Parmigiano-Reggiano, the cheese must be made using animal rennet.

• Check Labels for Clues: Look for terms like 'microbial enzymes,' 'vegetarian rennet,' or a Kosher symbol to identify vegetarian-friendly cheese.

• PDO Status Indicates Caution: Cheeses with a Protected Designation of Origin (PDO) certification, common in Europe, are likely made with animal rennet as part of their traditional recipe.

• Alternatives are Common: Due to high demand, most mass-produced cheeses today use non-animal coagulants like microbial or fermentation-produced chymosin.

What is Animal Rennet?

At the heart of why some cheeses are not vegetarian is an ingredient called rennet. Rennet is a complex of enzymes, primarily chymosin, that causes milk to coagulate and separate into solid curds and liquid whey. Traditionally, and for centuries, cheesemakers obtained this enzyme by extracting it from the inner lining of the fourth stomach of young, unweaned ruminant animals like calves, lambs, and kids. The young animals were not typically slaughtered solely for rennet, but it was a byproduct of the meat industry. Since this process requires the use of a slaughtered animal's stomach, any cheese made using animal rennet is not considered vegetarian.

Alternatives to Animal Rennet

In response to ethical concerns and the growing demand for vegetarian-friendly products, cheese manufacturers have developed several effective alternatives to animal rennet.

• Microbial Rennet: Derived from molds or fungi (like Rhizomucor miehei), microbial rennet is a cost-effective and widespread alternative. It is commonly used in many mass-produced cheeses in the United States and Europe.
• Fermentation-Produced Chymosin (FPC): This advanced form of microbial rennet is created using genetically engineered microorganisms that produce chymosin, an enzyme identical to the one found in animal rennet. FPC is highly efficient and is now the most common coagulant in commercial cheesemaking worldwide.
• Vegetable/Plant-Based Rennet: Sourced from plants like cardoon thistles, nettles, or figs, these enzymes are used in some traditional cheeses, particularly in parts of Spain and Portugal. However, they can sometimes impart a slightly bitter flavor, especially in aged cheeses.

Cheeses That Are Often Not Vegetarian

For vegetarians, the best practice is to always check the ingredient label, as even common cheeses can be made with either animal or non-animal rennet. However, certain traditional cheeses are almost always made with animal rennet, and some have legal requirements that mandate it.

Protected Designation of Origin (PDO) Cheeses

Many European cheeses are protected by a PDO status, which means their production must follow a strict, traditional process that often includes the use of animal rennet. These are some of the most common cheeses to watch out for:

• Parmigiano-Reggiano: Authentic Parmigiano-Reggiano, often referred to as 'parmesan,' is a hard, aged cheese from Italy that must be made with animal rennet to receive its official certification. Any product labeled vegetarian 'parmesan' is a substitute, sometimes labeled as 'Italian hard cheese'.
• Grana Padano: Similar to Parmesan, this hard Italian cheese is also a PDO product that legally requires the use of animal rennet.
• Pecorino Romano: This hard sheep's milk cheese from Italy uses lamb rennet in its traditional recipe and is not vegetarian.
• Gorgonzola: Traditional Gorgonzola is a blue cheese that uses animal rennet, though vegetarian alternatives exist.
• Gruyère: This hard Swiss cheese, when produced traditionally, uses animal rennet.
• Manchego: Spanish Manchego cheese also traditionally uses animal rennet.
• Roquefort: Another blue cheese, Roquefort, is typically made with animal rennet.

How to Identify Vegetarian Cheese

Becoming a savvy cheese shopper is essential for vegetarians. Since labeling requirements for rennet source can be inconsistent, a few strategies can help you make an informed choice.

• Check the Label: Look for specific phrasing in the ingredients list. Keywords like 'microbial enzymes,' 'vegetarian rennet,' or 'non-animal enzymes' indicate a vegetarian product. If the label only says 'enzymes' or 'rennet,' it is most likely animal-derived.
• Search for Certifications: Some cheeses carry certification logos that can quickly identify them as vegetarian. The official Vegetarian V-label or a Kosher certification (look for the 'K' or 'OU' symbol) is a reliable indicator that the cheese is rennet-free.
• Opt for Acid-Set Cheeses: Many fresh, soft cheeses do not require rennet at all and are coagulated using an acid like lemon juice or vinegar. These are almost always vegetarian and include ricotta, paneer, cottage cheese, and cream cheese.

Comparison: Animal vs. Non-Animal Rennet

Feature	Animal Rennet (Traditional)	Non-Animal Rennet (Modern)
Source	Stomach lining of young ruminant mammals (calves, lambs)	Microbial (fungi/molds) or plant-based
Availability	Limited; supply tied to veal industry	Widely available and abundant
Cost	More expensive due to limited supply	More economical to produce
Flavor Profile	Integral to traditional, complex flavor development in some aged cheeses	Generally produces consistent flavor, but can sometimes result in bitterness in aged cheeses
Usage	Required by law for certain PDO cheeses	Used in most large-scale commercial cheese production

The Verdict on Your Favorite Cheese

For vegetarians, the journey to a rennet-free diet requires careful label reading and a bit of knowledge about traditional cheesemaking practices. While artisanal and aged European cheeses are more likely to contain animal rennet, the good news is that most commercially produced American cheeses now use vegetarian alternatives. Many brands are also transparent about their rennet source, so a quick check of the packaging is often all it takes.

In conclusion, the simple pleasure of cheese can be enjoyed by vegetarians, but with some diligence. By understanding the role of rennet and knowing which specific varieties and certifications to look for, you can navigate the cheese aisle with confidence. For a deeper scientific dive into cheesemaking, consider exploring resources like the article on Rennet from ScienceDirect.

Safe Vegetarian Cheeses

• Ricotta
• Paneer
• Cottage Cheese
• Cream Cheese
• Swiss (many varieties, but check labels)
• Provolone (many varieties, but check labels)
• Most commercially produced blue cheeses, especially Stilton

Cheeses to Approach with Caution (Check Labels)

• Cheddar (especially artisanal varieties)
• Feta
• Mozzarella (especially traditional European types)
• Goat's Cheese (traditional French varieties often use animal rennet)
• Brie (some use animal rennet)
• Camembert (some use animal rennet)

Frequently Asked Questions

Why is some cheese not vegetarian?

Some cheese is not vegetarian because it is made using animal rennet, a coagulating enzyme traditionally extracted from the stomach lining of young calves, lambs, or kids. This process makes the cheese unsuitable for a vegetarian diet.

Is authentic Parmesan cheese vegetarian?

No, authentic Parmigiano-Reggiano is never vegetarian. It is a Protected Designation of Origin (PDO) product that, by law, must be made using animal rennet.

What is animal rennet?

Animal rennet is a complex of enzymes, primarily chymosin, that causes milk to curdle. It is traditionally sourced from the fourth stomach of young ruminant animals and is crucial for making many hard cheeses.

How can I tell if a cheese is vegetarian?

To tell if a cheese is vegetarian, check the ingredients list for 'microbial enzymes,' 'vegetarian rennet,' or similar phrases. A Kosher certification symbol can also indicate the cheese is vegetarian.

Are there vegetarian alternatives to non-vegetarian cheeses?

Yes, many brands produce vegetarian versions of popular cheeses by using microbial or plant-based rennet. For Parmesan, these are often labeled 'Italian hard cheese'.

Is Gorgonzola vegetarian?

No, traditional Gorgonzola is not vegetarian because it is a PDO product that uses animal rennet. However, some brands sell vegetarian-friendly blue cheese alternatives like Dolcelatte.

Are all hard cheeses non-vegetarian?

Not all hard cheeses are non-vegetarian. While many traditional hard cheeses use animal rennet, numerous commercially produced hard cheeses, including many cheddars and Swiss cheeses, are made with microbial rennet and are vegetarian.