What type of culture is a starter used in making cheese?

The type of culture used as a starter in making cheese is a bacterial culture. This is because the fermentation process that occurs in cheese-making primarily relies on specific strains of bacteria, such as Lactococcus lactis or Streptococcus thermophilus. These bacteria are responsible for converting lactose (the sugar found in milk) into lactic acid. The production of lactic acid is crucial because it lowers the pH of the milk, causing the proteins (casein) to coagulate, which leads to the formation of curds. The use of bacterial cultures not only helps in the initial coagulation of milk but also contributes to the development of flavor, texture, and preservation of the cheese throughout its aging process.

While yeast cultures are predominantly associated with processes like bread-making and fermentation of alcoholic beverages, and fungal cultures play a crucial role in certain types of cheeses (for example, blue cheese), the starter cultures for most cheese varieties are specifically bacterial. Viral cultures are not used in cheese-making as they do not play a role in fermentation or the production of dairy products.