Cheese May Not Be As Vegetarian-Safe As You Thought

Cheese is one of the most versatile — and popular — foodstuffs out there, even if it might not be best to eat it every day. Whether on pizza, with crackers, in a sandwich, part of a pasta dish, or simply on its own, there are so many ways to eat it. What's more, it's meat-free, so even if you're a vegetarian, you can enjoy it — right?

Not so. While there are plenty of vegetarian-friendly cheese options, and even some vegan cheese made with no animal milk whatsoever, you might be surprised that some cheese isn't actually suitable for those following a vegetarian diet (via The Vegetarian Society).

It all comes down to something used during the process of making cheese — this little ingredient will determine whether or not your favorite cheese is okay for vegetarians to eat. The ingredient in question is the enzyme rennet, which plays a vital part in the making of one of our favorite foods.

Rennet is used to set cheese. Of course, cheese starts out life as milk, and when rennet is stirred into it, it makes it separate into curds (which are solid) and whey (which is liquid). The curds are what get turned into cheese.

While rennet can be produced from vegetables and fungi, or made using genetic modification (via LoveToKnow), it's traditionally sourced from the stomach lining of calves — often a byproduct of the meat industry. When a calf is slaughtered, the lining of its stomach is washed, dried, and softened. From here, rennet can be extracted, ready for use in cheese (via The Vegetarian Society).

As a result, certain cheeses — including more than a few moldy varieties — are never vegetarian, as animal rennet is required. These types of cheese include Parmigiano-Reggiano, gorgonzola, Roquefort and Grana Padano — if you're a vegetarian, you'll have to give these cheeses a miss. However, vegetarian rennet is used in the production of a lot of cheese today, so you won't have to give up your favorite dairy products completely — you might just have to do a little more research than you thought. Why not give halloumi a try, for example?