What is Rennet and Why Isn't it Vegetarian?
The primary reason some cheeses are not suitable for vegetarians is the use of animal rennet. Rennet is a complex set of enzymes, primarily chymosin, produced in the stomachs of young, unweaned ruminant mammals, such as calves, lambs, and goats. Its purpose in cheesemaking is to coagulate the milk, separating it into solid curds and liquid whey. Since the traditional extraction process involves slaughtering the animal to obtain the stomach lining, the resulting cheese is not considered vegetarian.
Historically, this was the only method available. However, modern cheesemaking has developed several vegetarian-friendly alternatives, including microbial rennet (from molds), vegetable rennet (from plants like thistle or fig leaves), and fermentation-produced chymosin (FPC), which is a genetically engineered version of chymosin produced by microorganisms. While these alternatives exist, many traditional or regionally protected cheeses are still required by law to use animal rennet to bear their authentic name.
Hard Cheeses That Are Traditionally Non-Vegetarian
Many of the world's most famous hard and aged cheeses are traditionally made with animal rennet. These include:
- Parmigiano-Reggiano: This is perhaps the most well-known example. Italian law dictates that to be called Parmigiano-Reggiano, the cheese must be made with calf rennet. While imitation "parmesan" is often vegetarian, the authentic version is not.
- Grana Padano: Similar to Parmesan, Grana Padano is also traditionally made with animal rennet.
- Pecorino Romano: This hard sheep's milk cheese traditionally uses lamb rennet.
- Gruyère: This classic Swiss cheese is another example of a product that traditionally relies on animal rennet.
- Manchego: The traditional Spanish sheep's milk cheese often uses animal rennet, though vegetarian versions exist.
- Gorgonzola: Many traditional varieties of this blue cheese use animal rennet.
When purchasing these cheeses, especially from Europe, it is safest for vegetarians to assume they are non-vegetarian unless the label explicitly states otherwise.
How to Read a Cheese Label for Rennet
Identifying vegetarian cheese requires careful attention to the ingredient list. The terminology can sometimes be vague, but there are clear clues to look for:
- Look for 'microbial enzymes' or 'vegetarian rennet': If the product is made with a non-animal coagulant, the manufacturer will usually highlight this. Look for phrases like "microbial enzymes," "vegetarian enzymes," "vegetable rennet," or "non-animal rennet".
- Avoid 'animal enzymes' or just 'enzymes': If the label lists "animal enzymes" or simply "enzymes" without further clarification, it's safer to assume that animal rennet was used.
- Check for Kosher certification: Certified Kosher cheese will never contain animal rennet due to Jewish dietary laws prohibiting the mixing of milk and meat products. Look for a "K" or "OU" symbol on the packaging.
- Be wary of traditional names: As mentioned, cheeses with protected designations like Parmigiano-Reggiano are almost certainly made with animal rennet, regardless of what the US-style label says.
Soft and Fresh Cheeses That are Often Vegetarian
Not all cheese-making relies on rennet. Many soft and fresh cheeses are coagulated using an acid, such as lemon juice or vinegar, making them naturally vegetarian-friendly. Common examples include:
- Paneer: A fresh cheese popular in South Asian cuisine, paneer is traditionally made by curdling milk with acid.
- Cottage Cheese: This soft, fresh cheese is typically made by curdling milk with acid.
- Ricotta: Italian ricotta is made from whey left over from other cheese production and coagulated with acid or heat, making it generally vegetarian.
- Cream Cheese: The soft, spreadable cheese is also made with an acid-based process.
- Mozzarella (young): While traditional mozzarella di bufala can use animal rennet, most mass-produced, younger mozzarella available in stores uses microbial enzymes.
Comparison of Vegetarian vs. Non-Vegetarian Cheeses
To simplify your shopping, here is a quick reference table.
| Cheese Type | Traditional Rennet Status | How to Identify a Vegetarian Version | Common Alternatives | |
|---|---|---|---|---|
| Parmigiano-Reggiano | Non-Vegetarian (Calf Rennet) | Only available as "Parmesan-style" or clearly labeled "Vegetarian Parmesan" | Nutritional Yeast: Sprinkled for a savory, nutty flavor. | Vegan Parmesan: Made from nuts. |
| Cheddar | Often Non-Vegetarian (Animal Rennet) | Look for "Microbial Enzymes" or "Vegetarian Rennet" on the label | Many large brands are vegetarian. Check the label carefully. | |
| Gruyère | Non-Vegetarian (Animal Rennet) | Seek out brands specifically advertising "vegetarian rennet" or consider Kosher varieties. | Vegan Alternatives: Nut-based artisan cheeses offer rich flavors. | |
| Gorgonzola | Often Non-Vegetarian (Animal Rennet) | Find brands that specify using microbial or vegetable rennet. | Dolcelatte: A milder blue cheese that is often vegetarian. | Vegan Blue Cheese: Artisan vegan options are now available. |
| Mozzarella | Can be Non-Vegetarian (Traditional) | Look for brands with "Microbial Enzymes" on the label, especially for fresh mozzarella. | Many common, fresh mozzarella balls sold in tubs are vegetarian. | |
| Ricotta & Cream Cheese | Vegetarian (Acid Coagulant) | These cheeses almost always use an acid-based coagulation process. | Safe bet for vegetarians without needing extensive label checking. |
The Rise of Vegetarian and Vegan Cheese Alternatives
The market for vegetarian and vegan cheese has exploded in recent years, offering more options than ever before. For those who prefer to avoid animal rennet, this is excellent news. Major brands and artisan producers alike are creating delicious cheeses using plant-based or microbial rennet. Furthermore, vegan cheese, which contains no dairy at all, has become increasingly sophisticated. Made from ingredients like cashews, almonds, and coconut oil, these products can replicate the taste and texture of their dairy counterparts for everything from parmesan to gooey mozzarella.
Conclusion
When navigating the world of cheese as a vegetarian, the key is awareness. The simple rule of assuming that most hard, traditional European cheeses are non-vegetarian is a good starting point. However, the most reliable method is to always check the ingredient label for terms like "microbial enzymes" or "vegetarian rennet." With the growth of the vegetarian and vegan food market, finding safe and delicious cheese options is easier than ever, allowing vegetarians to enjoy their diet without any hidden surprises. For further reading, an excellent resource on the intricacies of cheese production is the Wikipedia page on Rennet.
