This results in an approximately 10-fold concentration of fat and casein. Cheese contains almost all of the essential vitamins, minerals, and other nutrients found in milk. Manufacturing is, essentially, the first 24 hours of cheesemaking, from pasteurization to final salting. Ripening is the process of aging. The following steps are the basic method for making cheese.
Pasteurization is a heat treatment of milk to destroy pathogenic bacteria that cause human disease.
Pasteurization does not sterilize the milk. Some pathogenic bacteria can survive pasteurization. Many nonpathogenic bacteria and bacterial spores will remain in the milk. Milk left standing will eventually sour because of these bacteria. Classically, this process is performed by bacteria.