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. Acid is essential to the production of good cheese. However, if there is too much acid in the milk the cheese will be crumbly.