Strictly speaking, vegetarians would also have to avoid cheese. Fundamentally, cheese making has not changed over the centuries, apart from technological advances that have changed the workflow enormously. Cheese is particularly popular among people who don’t eat meat. Vegetarians, for example, only eat products that come from living animals and therefore avoid foods such as fish and meat. But classic cheese production uses milk from live animals, but an animal enzyme is needed to coagulate it.

Traditionally, rennet is used for this purpose, which is obtained from the stomachs of young calves of milk-drinking age. For this purpose, the animal is slaughtered and its parts such as meat and bones are used. The rennet is a mixture of the enzymes chymosin and pepsin, which is needed to precipitate milk protein in the production of cheese. However, this can also be produced microbially or added together with lactic acid bacteria. However, rennet is needed for almost all known types of hard and semi-hard cheese. Cream cheese can also contain animal rennet. Normally it is made with lactic acid bacteria from quark or yoghurt.

However, the amount of animal rennet needed to make cheese is rather limited. Only around 35 percent of global cheese production can be produced with natural rennet. The rest is made with alternatives.

Mainly with microbial rennet. This is based on cultured mold cultures whose metabolism produces a coagulation enzyme. Its advantages: It can be multiplied indefinitely and is many times cheaper than natural rennet. Cheese with microbial rennet is particularly popular with vegetarians. The disadvantage: Bitter peptides can develop when cheese matures for a longer period of time.

An alternative to natural enzymes is chymosin, which is produced using genetically modified microorganisms. The substance is banned for the production of organic food.

There are also plant species that have protein-splitting properties such as bedstraws, papayas or figs. The plant rennet brings unusual taste results to cheese and is therefore rarely used.

Internationally, rennet is classified as a production aid and not as a food additive. This means the substance does not require declaration and is usually not listed on the packaging. Things are now different in organic supermarkets: it is almost always stated whether animal rennet or one of the substitutes was used. If you want to be on the safe side as to whether a cheese contains animal rennet, you have to ask the manufacturer. A few years ago, the Vegetarian Association published a list of which types of cheese use which type of rennet. You can view them here.