Is L-Cysteine vegan?
Short answer
L-Cysteine is depends. L-cysteine is often made from human hair, duck feathers or pig bristles — but a synthetic vegan version exists.
Key takeaways
- Verdict: L-Cysteine is depends.
- Commonly found in: Commercial bread, Bagels (notably Einstein Bros, some Subway breads historically), Pizza dough, Pre-packaged pastries.
- Vegan alternatives: Breads made with ascorbic acid as a dough conditioner instead, Home-baked or bakery sourdough.
- Also listed as: cysteine, E920.
- Scan any barcode with VeggieOS (100% free) for an instant vegan verdict.
Also known as: cysteine, E920
What it is
An amino acid used as a dough conditioner in bread and bagels.
Why depends
Conventional L-cysteine is rendered from hair and feathers. A bacterial-fermentation version (Ajinomoto's process) is vegan, but labels rarely specify the source.
Where you'll find it
- Commercial bread
- Bagels (notably Einstein Bros, some Subway breads historically)
- Pizza dough
- Pre-packaged pastries
Vegan alternatives
- Breads made with ascorbic acid as a dough conditioner instead
- Home-baked or bakery sourdough
FAQ
- How do I know if a bread's L-cysteine is vegan?
- Contact the manufacturer. Brands like Dave's Killer Bread state they use synthetic L-cysteine; many do not disclose.