Starter Culture

Also called a "friendly" culture, starter cultures are added to milk at the start of the cheesemaking process. The cultures change the lactose or milk sugar, the carbohydrate in milk, into lactic acid. This equalizes the pH so the milk protein will form curds when the rennet is added. The cultures used by the cheesemaker are a closely guarded secret as they contribute to the distinct qualities of each cheese.

The California Milk Advisory Board