What Enzymes Are Used As Catalysts in Making Cheese?

Enzymes are what make milk curdle or coagulate. So milk requires enzymes if it is to become some form of cheese whether it is made from the milk of sheep, goats, cows or buffalo. If it is natural enzymes then the rennet comes from one of a calf stomachs, they have four. Calves have this enzyme because they require it in order to be able to digest their mother’s milk.
When using the natural or animal rennet it is best from calves who have not yet been weaned. If they are older calves there will be no Chymosin but they will have more pepsin. This can’t be used in all types of cheeses. Of course just as there is calf rennet there is also kid goat and lamb rennet.

There are alternatives to natural rennet. One technical name for rennet is Chymosin. But rennet actually contains two enzymes one is Chymosin the other is Pepsin. The alternatives to the animal rennet are enzymes created from microbes or vegetable enzymes for the vegetarian cheese consumer. Microbial rennet is laboratory grown for vegetarians from mold, fungus or yeast.

Then there is the genetically modified rennet or GMO. A GMO is made in a laboratory from a derivative of animal rennet which means a chemical substance from a parent substance which may be animal. There are some European countries that ban GMO rennet for sale in their country but allow its use for cheeses shipped to countries that allow it in cheeses.

Many European countries continue to use natural enzymes in making their traditional cheeses. These are more expensive than man or laboratory created enzymes. Microbial rennet is from Mucor Miehei or also known as a microbial coagulant which is accepted and is actually an extract of a type of mold that is nontoxic and nonpathogenic to humans. So it is safe to consume products using this form of enzyme.

Besides animal rennet there are other sources of rennet. It can be from certain plants and called vegetable rennet but it is rare to find it in North America. Vegetable rennet comes from very specific plants which have certain enzymes that can curdle milk.

Then there is FPC or Fermentation Produced Chymosin rennet introduced in 1990. It is very inexpensive to produce and is used almost extensively in mass cheese production in the US. This particular rennet comes under a cloud as it may be considered a generically altered product.