Pepsin (Gastric Enzyme) — Hidden Processing Agent — Is It Vegan?
Also known as: Porcine pepsin, Gastric protease, E1101
Not Vegan
This processing agent is derived from animals or their byproducts.
Not required on labels
Rarely required on labels. Listed as 'pepsin' or 'enzyme' where declared.
Source
Extracted from the stomach lining of pigs (predominantly) or cattle. An acid protease enzyme naturally produced by the gastric glands.
Used In
Some cheese making (particularly traditional Italian cheeses in combination with rennet), gelatin production (acid hydrolysis), pharmaceutical applications, research use.
How to Avoid
Difficult to identify without manufacturer confirmation. Traditional Italian cheese production using rennet-pepsin combinations is a minority of production — most commercial cheese uses FPC rennet.
Editorial Notes
Pepsin has been partially covered in the processing agents section already (see main Pepsin entry). In the context of cheese production, pepsin is often combined with rennet to produce specific proteolytic (protein-breaking) activity that contributes to cheese flavour development. Its use is more common in traditional than in industrial cheesemaking.