Are All Types of Cheese Suitable for a Vegetarian Diet?

Parmigiano-Reggiano hard cheese on cutting board
Parmigiano-Reggiano hard cheese on cutting board

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Vegetarian cheese lovers, we hope you're sitting down. You likely assumed that cheese—all cheese—was green lighted for vegetarians, but your favorite snack may actually contain animal products. We caught up with Josh Windsor, caves manager at Murray's Cheese, to learn which cheeses are suitable for vegetarians and which ones aren't. "Often when we talk about whether a cheese is vegetarian, or not, we are referring to the type of rennet used in making the cheese," says Windsor. "Rennet is an enzyme that helps coagulate milk. This is the big step in cheese making that binds the proteins in milk together. There are a few different kinds of rennet that cheese makers can use, some of which are vegetarian and others that are not."

Related: Our Guide to Cheese Tools

Let's Review Rennet

As Windsor explains, traditionally, rennet is extracted from the abomasum (fourth chamber of the stomach) of a ruminant, usually a calf, lamb, or kid. "This rennet is a complex blend of enzymes that is very good at coagulating milk. It is this form of rennet that is not vegetarian-friendly. When listed on a cheese label, it can be called several names: animal rennet, traditional rennet, calf rennet, and so on. Traditional rennet is found in most name protected European cheeses (such as Parmigiano-Reggiano, Gruyère, Manchego) and is often preferred for making hard, longer aged cheese," he says.

On the other hand, purely vegetarian cheese—that is, one that's suitable for vegetarians to consume—has a rennet derived from one of three sources. "The oldest and most traditional is generally labeled vegetable rennet. These are enzymes extracted from plant sources. For example, the thistle rennet Tortas of the Iberian Peninsula use a rennet that comes from the cardoon thistle and produce a creamy, spoonable cheese," says Windsor. "Modern vegetarian rennet, which is often labeled vegetarian or microbial rennet, is derived from various microbes. Some versions are the same chemical compounds as found in traditional rennet but are produced by bacteria or yeasts in a lab."

How Can You Tell If a Cheese Is Vegetarian?

Now that you're all up to speed on the rennet situation, let's consider this all on a practical level. You're at the grocery store or specialty cheese shop buying cheese or scouting out dairy dreams online. How can you tell if a cheese is vegetarian or not? Windsor says the best way to determine if a cheese is vegetarian is to look at the label or (if available) ask the cheesemonger at the counter. "The FDA only requires the word rennet or enzymes appear on a cheese label. There is no requirement for a cheese maker to disclose what kind of rennet is used for a particular cheese," says Windsor. If you only see "rennet" or "enzymes" on an ingredient list, you may be out of luck unless an employee has additional info.

In some cases, ingredient lists give more information. "If an ingredient list contains traditional rennet, animal rennet, kid rennet or lamb rennet, it is not suitable for vegetarians," summarizes Windsor. "If an ingredient list contains vegetable rennet, vegetarian rennet, vegetable rennet, thistle rennet, fermentation produced rennet, or FPC Chymosin, the cheese is suitable for vegetarians." If a cheese has a Kosher or Halal certification, it will be suitable for vegetarians, too, by default.

When you find yourself on a quest for otherworldly vegetarian cheese and are met with "rennet" or "enzymes" on the cheese label, follow Windsor's rule of thumb: "In general, traditional cheese styles, European cheeses, hard cheeses, and cheeses aged more than six months are more likely use animal rennet," says Windsor. "A Wisconsin produced mild cheddar is more likely to be vegetarian than an imported, 18-month-old Comté. Most soft cheeses are made with vegetarian rennet," he continues.

What About Parmigiano-Reggiano?

Thankfully, Windsor is ready to guide us through this conundrum. "Many cheese makers prefer animal rennet for long-aged, hard cheeses. So, for a one- to five-year-old cheese like Parmigiano-Reggiano, the list of available substitutions becomes smaller. However, Parmigiano-Reggiano is an Italian PDO (Protected Designation of Origin) cheese," says Windsor, noting that this cheese can only be made in a specific region of Italy using techniques specified by the Consorzio del Formaggio Parmigiano-Reggiano, one of which requires the use of animal rennet. "Much of the parm purchased in the U.S. is more generally termed 'Parmesan.' Parmesan is made similarly to Parmigiano-Reggiano but does not meet all the requirements of the consortium, mainly the geographic boundaries. American Parmesan makers can use whatever rennet they like, and many produce a vegetarian Parmesan cheese, which is labeled as such," he shares, much to the relief of vegetarians nationwide.

If you can't find a vegetarian Parmesan cheese and don't want to eat animal rennet found in Parmigiano-Reggiano, Windsor recommends a Dry Jack cheese as a substitute. "Dry Jack is an aged version of Monterey Jack that originated in California during World War I. At the time, imports of hard Italian cheeses had become exceedingly rare," he comments. "Jack cheese was aged for longer periods of time and became a popular substitute for a grateable Italian cheese. Luckily, both producers of Dry Jack, Vella Cheese Company and Rumiano Cheese Company, make their cheese using vegetarian rennet."

Any Other Cheeses Vegetarians Should Avoid?

Before we part, it's important to note that clothbound or bandage-wrapped cheddar might not be suitable for vegetarians. "Many of the cheddar cheeses we eat are aged in wax or sealed bags. These cheddars never produce a rind and are often found in blocks, loafs, slices, and shreds at the grocery store," says Windsor. He explains that another way to age cheddar is to wrap the cheese in cheesecloth and allow it to grow a rind in a cave. "This style of cheddar aging is much more labor-intensive, but produces a more dry, crumbly texture and complex flavor profile," says Windsor, elaborating that to seal the cheesecloth to the surface of the cheese, the young cheddar is often painted with a melted fat, in some cases butter, but in other cases lard, which comes from pigs. "There is no requirement in the U.S. to list either on the label, so it can be very difficult to determine which is being used. Often this will require some internet sleuthing or access to an informed cheesemonger to assess," he adds. The more you know, friends.