Animal rennet is found in many foods where you wouldn’t expect it – always a challenge for vegetarians. We tell you what rennet has to do with cheese and what alternatives there are.
If you eat vegetarian or vegan, it is particularly interesting for you to know which foods contain animal products – and whether they come from dead or living animals.
What is animal rennet?
Animal rennet is a mixture of different enzymes that occurs naturally in the gastric mucosa of young calves and other ruminants. The special enzymes break down the milk protein so that the milk thickens. This is the only way the calves can digest their mother’s milk. Since this is also true for humans, animal rennet is often added to dairy products to make them easier for us to digest.
If you eat vegan and completely avoid dairy products, animal rennet is not a problem for you, as it is only used in dairy products. If you follow a vegetarian diet, you must decide for yourself whether obtaining animal rennet is compatible with your lifestyle.
How is animal rennet obtained?
In order for animal rennet to be processed into food, it must be extracted from the stomachs of ruminants.
Since rennet is naturally there to make breast milk digestible, each mammal has a special rennet enzyme that is tailored to its own breast milk. In Europe, most dairy products come from cows, which is why rennet from young calves is often used in our food, but also from sheep or goats. The rennet quality is better the younger the animal was. This is because young animals drink a lot of breast milk and produce more rennet.
In order to use animal rennet for food, the animal stomachs are placed in a special solution – this is how the enzyme is released from the mucous membrane. It is then cleaned and preserved in several steps. All that remains is the enzyme and no stomach or other meat parts – the stomachs themselves, however, can only be taken from dead animals. The calves are not killed specifically for rennet – instead, the stomachs of animals slaughtered for meat production are used.
Animal rennet in cheese
Animal rennet breaks down milk proteins and allows milk to thicken without turning sour. It is precisely this property that is needed to produce sweet milk cheese – this includes most types of hard and semi-hard cheese. Many types of cheese only get their typical consistency with the help of rennet – without rennet they probably would not exist.
Are there alternatives to animal rennet?
There are some plant enzymes that work in a similar way to animal rennet. They are found in so-called rennet herbs, but also in the juice of papaya, pineapple or fig trees. However, they are only used for a few types of cheese because they affect the taste too much.
Rennet substitutes are often used in cheese production. These substances are often obtained by fermenting certain molds with microorganisms. In addition to moulds, however, these microorganisms also feed on other nutrient media that are not always vegetable.
Another alternative to animal rennet is an enzyme produced by genetically modified microorganisms. The genetic information from the mammalian stomach is implanted in the microorganisms so that they produce enzymes that are as similar as possible to animal rennet. However, there are currently no long-term studies on how GM foods affect our bodies – so GM foods should be treated with caution. This rennet alternative is not approved for organic food.
