Which ingredients are vegetarian

Whey is a milk product, so it fits a vegetarian diet on the face of it. The complication sits upstream. Whey is what drains off when milk is curdled for cheese, and traditional cheesemaking curdles milk with rennet from a slaughtered calf's stomach. Vegetarians who avoid animal rennet look for whey from cheese set with microbial or fermentation-produced coagulant, which most large manufacturers now use.

No. Gelatin is boiled out of the skin, bones, and connective tissue of pigs, cattle, or fish, which makes it a slaughter product and places it outside both diets. EU rules treat gelatine as a food ingredient instead of an additive, so it is listed by name and never as an E-number.

Carmine comes from cochineal insects that are killed and crushed for the dye, so it sits outside a vegan diet without argument. Vegetarians divide on it, and most vegetarian certification schemes exclude it. The same reasoning applies to shellac.

It settles the harder half. A vegetarian mark rules out the slaughter-derived additives, which are the ones hardest to spot. What remains is the dairy and egg group plus the source-dependent emulsifiers, and those are exactly the ones that turn up most often in bread, chocolate, and baked goods.