Step Two:

Milk is then typically pasteurized by heating the milk to 160 degrees for 15 seconds. This eliminates any bacteria present in the milk. This process is non-selective and kills all bacteria that are present in the milk, whether favorable or harmful. Favorable bacteria will be added back to the milk later in the form of starter cultures used in the cheese making process. Some cheese are made from raw milk or milk that is not pasteurized. If cheese is made from raw milk, it must be held for aging by the cheese maker for at least 90 days after it is made. No pathogens or harmful bacteria would be able to live that long in cheese.