Ingredients and products
Is L-cysteine (E920) vegan?
Short answer
Not always. It may come from keratin (feathers, hair) or from fermentation. In bread it improves dough. Ask the bakery or read the spec.
E920 is a permitted additive. The source is not visible on a standard roll label.
Fermentation versions are more common now — “more common” is not a guarantee.