What Enzymes Are Not Vegan? A Guide to Hidden Animal Ingredients

Many people don't realize that some enzymes used to process food and supplements are derived from animal sources, posing a challenge for those on a plant-based diet. This guide will help you identify the specific animal-derived enzymes you need to be aware of and how to find vegan-friendly alternatives.

Quick Summary

An essential guide for vegans identifying enzymes derived from animal sources, such as rennet, pepsin, and isinglass, which are used in food, beverages, and supplements. Understand their origins and find out how to ensure products are vegan-friendly.

Key Points

• Rennet: Traditionally sourced from calf stomachs, rennet is used in cheesemaking, making many traditional cheeses non-vegan.

• Pepsin: Derived from the stomach lining of pigs, pepsin is a non-vegan protease found in some digestive supplements and cheese.

• Isinglass: This clarifying agent, made from fish swim bladders, is used to filter some beers and wines, rendering them non-vegan.

• Lysozyme: Commonly extracted from chicken egg whites, lysozyme acts as a preservative (E1105) in various foods, including cheese and wine.

• Digestive Enzymes: Some supplements contain pancreatin, trypsin, and chymotrypsin, which are typically derived from animal pancreases.

• Labeling: Simply seeing the word "enzymes" on an ingredients list is not enough; manufacturers must be contacted or a certified vegan logo must be present to be sure of the source.

• Vegan Alternatives: Modern biotechnology offers vegan versions of most enzymes, such as microbial rennet and fungal proteases, making many animal-free alternatives widely available.

Understanding Vegan and Non-Vegan Enzymes

Enzymes are complex proteins that act as catalysts for various chemical reactions in living organisms. In food production, they are used for everything from coagulation and clarification to flavor development. While many enzymes used today are produced from microbial or plant-based sources, historically, and sometimes currently, they are extracted directly from animal byproducts. For vegans, consuming these animal-derived enzymes is a concern, making it crucial to understand their origins and applications.

Non-Vegan Enzymes Derived from Animals

Several key enzymes are traditionally and sometimes currently sourced from animals. Recognizing these is the first step toward avoiding them.

Rennet (Chymosin)

Perhaps the most well-known non-vegan enzyme, traditional rennet is a complex mixture of enzymes, with chymosin being the key component.

• Source: It is extracted from the stomach lining of young, unweaned ruminant animals, such as calves, lambs, or kids, typically as a byproduct of the meat industry.
• Application: It is used in cheesemaking to curdle milk, separating it into solid curds and liquid whey. Cheeses requiring animal rennet for traditional certification, like true Parmigiano-Reggiano, are not vegan.

Pepsin

Pepsin is a digestive enzyme that breaks down proteins.

• Source: It is typically derived from the stomach lining of pigs (porcine pepsin).
• Application: It is sometimes used as a substitute for chymosin in cheesemaking and is also found in some digestive enzyme supplements.

Isinglass

Isinglass is not a classic enzyme but a protein-based substance used in processing that can contain active enzymatic components.

• Source: It is a type of collagen obtained from the dried swim bladders of fish.
• Application: It is used as a fining agent to clarify and clear impurities from beverages like beer and wine. While trace amounts remain, its use makes the final product non-vegan.

Lysozyme (E1105)

Lysozyme is an antimicrobial enzyme used as a preservative in certain foods.

• Source: The most common commercial source is chicken egg whites.
• Application: It is added to various products, including some semi-hard cheeses, wine, and certain pre-packaged foods, to prevent spoilage.

Pancreatin, Trypsin, and Chymotrypsin

These are a family of digestive enzymes often used in supplemental form.

• Source: They are derived from the pancreas of animals, primarily pigs or cows.
• Application: Found in digestive health supplements prescribed for individuals with pancreatic insufficiency and other digestive issues.

Comparison of Animal-Derived vs. Vegan-Friendly Enzymes

Enzyme Name	Non-Vegan Source	Common Applications	Vegan-Friendly Alternatives
Rennet (Chymosin)	Stomach lining of young ruminants (calves, lambs)	Cheesemaking	Microbial rennet (from molds/fungi), Fermentation-Produced Chymosin (FPC), plant-based coagulants
Pepsin	Stomach lining of pigs	Digestive supplements, cheesemaking	Fungal protease enzymes, plant-based alternatives
Isinglass	Fish swim bladders	Clarifying agent in beer, wine	Bentonite clay, pea protein, moss, seaweed, charcoal
Lysozyme (E1105)	Chicken egg whites	Preservative in cheese, wine, tofu	Alternative food preservation methods; check labels for source
Pancreatin, Trypsin, Chymotrypsin	Animal pancreas (pigs, cows)	Digestive enzyme supplements	Fungal or plant-derived enzyme supplements (e.g., bromelain, papain)

How to Check for Hidden Non-Vegan Enzymes

Being vigilant about food labels is essential, as manufacturers are not always required to specify the source of an enzyme. Here are some strategies to help you avoid non-vegan enzymes:

• Read Ingredient Lists Carefully: Look for specific terms like "animal rennet," "porcine pepsin," or E-numbers like E1105. However, if the label simply states "enzymes," it might be derived from an animal source without being specified.
• Search for Vegan Certifications: The most reliable method is to look for a certified vegan logo on the packaging. This guarantees that no animal-derived ingredients or processing aids were used.
• Contact the Manufacturer: If in doubt, reach out to the food producer directly. Many companies now have clear information on their websites regarding vegan status and ingredient sourcing.
• Consult Vegan Databases: Online resources like Barnivore for alcoholic beverages or dedicated vegan ingredient checker apps can be invaluable for confirming the status of a product.
• Be Wary of Cheese Labels: Unless specified as "microbial rennet" or "vegetable rennet," assume rennet in cheese is from an animal source. Many traditional European cheeses, especially aged ones, use animal rennet.

Vegan Alternatives to Look For

Fortunately, a wide range of vegan-friendly alternatives exists for most non-vegan enzymes in the food industry. These are often produced via microbial fermentation or extracted from plants.

• Microbial Rennet and FPC: Most commercially produced cheese today, especially in North America, uses microbial rennet derived from fungi or Fermentation-Produced Chymosin (FPC).
• Plant-Based Coagulants: Certain plants, like cardoon thistle or artichoke, contain enzymes that can curdle milk and are used in some artisanal cheesemaking.
• Vegan Fining Agents: Vegan beer and wine are clarified using agents like bentonite clay, activated charcoal, or certain seaweed products instead of isinglass.
• Vegan Digestive Supplements: Many health food stores offer a wide selection of vegan digestive enzymes, such as bromelain from pineapple or papain from papaya.

Conclusion

While the presence of hidden animal-derived enzymes like rennet, pepsin, and isinglass presents a challenge for vegans, awareness and diligence make navigating ingredient lists much easier. By understanding which enzymes are not vegan, seeking certified products, and contacting manufacturers when necessary, you can make informed choices that align with your plant-based values. As the demand for vegan products grows, the industry continues to innovate, providing more transparent and cruelty-free options for food processing and supplements.

References

• Anti Additive Clean Label Organization. (2023, June 9). Watch Out: These 7 Common Food Additives Are Not Vegan. Retrieved October 12, 2025, from https://www.anti-a.org/news/en/these-7-common-food-additives-are-not-vegan
• Utopia.org. (2022, July 18). Is Rennet Vegan? The Answer Might Surprise You. Retrieved October 12, 2025, from https://utopia.org/guide/is-rennet-vegan-the-answer-might-surprise-you/
• Biolaxi Enzymes Pvt Ltd. (2025, June 10). The Importance of Animal-Derived Enzymes in Digestion. Retrieved October 12, 2025, from https://www.biolaxienzymes.com/the-importance-of-animal-derived-enzymes-in-digestion/
• Creative Enzymes. (n.d.). Lysozyme in Everyday Life: Its Presence in Foods and Beyond. Retrieved October 12, 2025, from https://www.creative-enzymes.com/resource/lysozyme-in-everyday-life-its-presence-in-foods-and-beyond_253.html
• Wikipedia. (n.d.). Rennet. Retrieved October 12, 2025, from https://en.wikipedia.org/wiki/Rennet
• Fermentaholics. (n.d.). Rennet: Quality Enzyme for Cheese's Flavors and Textures. Retrieved October 12, 2025, from https://fermentaholics.com/what-is-rennet/
• The Vegan Society. (2015, August 7). How to avoid buying non-vegan products. Retrieved October 12, 2025, from https://www.vegansociety.com/news/blog/how-avoid-buying-non-vegan-products
• Wikipedia. (n.d.). Isinglass. Retrieved October 12, 2025, from https://en.wikipedia.org/wiki/Isinglass

Frequently Asked Questions

Is all cheese made with animal rennet?

No, not all cheese is made with animal rennet. Many manufacturers use vegetarian-friendly alternatives like microbial rennet (from molds and fungi) or fermentation-produced chymosin. You must check the label for specific language or a vegan certification.

What is the difference between animal rennet and microbial rennet?

Animal rennet is extracted from the stomach of young ruminants, such as calves. Microbial rennet is produced via fermentation using molds or fungi, making it a vegetarian and vegan-friendly alternative for cheesemaking.

Are digestive enzyme supplements vegan?

Not all digestive enzyme supplements are vegan. Pancreatin, trypsin, and chymotrypsin are often derived from animal pancreases. However, many vegan alternatives use enzymes from plants like pineapple (bromelain) or papaya (papain).

Is all wine vegan?

No, not all wine is vegan. Some winemakers use animal-derived fining agents, such as isinglass (from fish bladders) or egg albumen, to clarify the wine and remove impurities. Many vegan-friendly alternatives are used, but checking for a vegan label or using resources like Barnivore is recommended.

How can I tell if a food product uses animal-derived enzymes if not explicitly stated?

The most reliable way is to look for a specific vegan certification logo. If not available, contact the manufacturer directly to inquire about the sourcing of their enzymes. Generic labeling like "enzymes" does not guarantee a vegan product.

Are there vegan-friendly alternatives for isinglass in brewing?

Yes, common vegan-friendly fining agents used in brewing include bentonite clay, pea protein, and Irish moss (a seaweed). Many craft breweries now label their products as vegan due to these alternatives.

Is lysozyme always from eggs?

The lysozyme used commercially, identified by the E-number E1105, is most commonly obtained from chicken egg whites. However, research is ongoing for alternative microbial or plant-based sources, so confirming the source is necessary if not explicitly vegan-certified.