Shopping and labels
Which sauces are often not vegan?
Short answer
Worcestershire (anchovy), fish and oyster sauce, some barbecue sauces with honey, pesto with cheese, Caesar with anchovy and egg, mayonnaise with egg. Soy sauce and sriracha are often fine — still check.
Anchovy and fish sauce are classic hidden animals in Asian and British cooking.
Vegan versions exist (Worcestershire without fish, for example).