Is animal rennet used in making mozzarella?

Yes, animal rennet is traditionally used in making mozzarella. Rennet is an enzyme that is obtained from the stomachs of young mammals, usually calves, and it helps to coagulate the milk proteins into curds. This process is essential in the production of cheese.

However, there are also vegetarian and vegan alternatives to animal rennet available, which are made using microbial or plant-based enzymes. These alternatives are often used in the production of mozzarella that is suitable for vegetarians and vegans.