Most hard cheeses are made with one (or both) of two kinds of cultures. These cultures promote the formation of lactic acid in the milk, creating the acidity required for curd formation as well as adding flavor.

Cultures are added to the milk at a specific temperature, stirred in well, then allowed to set for some period of time according to the cheese recipe.

Mesophilic culture is used in lower temperature recipes. It works best at temperatures between 86