Swiss Cheese

Swiss cheese is made by heating cow's milk at high temperatures and then lifting the curd from the whey in one mass in a fine-mesh net. This mass is then shaped into blocks, salted with strong brine, wrapped to prevent drying, and stored for six to eight weeks to ferment at 80º Fahrenheit. During the weeks of curing, the cultures begin to grow causing the body of the cheese to break down, the holes to form and that great Swiss cheese flavor to develop. The famous "holes" in Swiss cheese develop because of the gas that occurs naturally from the breakdown of milk sugar in the cheese. The cheese maker takes periodic samples to determine that the holes of the cheese are properly developed. According to Marcia (p3) Switzerland has been making great cheese since the 15th century, when monks who lived in the mountain passes made large amounts of it to feed travelers.

A search on "swiss cheese holes" revealed that gassy bacteria are behind all that holey cheese. In order to make cheese, you need the help of bacteria. Starter cultures containing bacteria are added to milk, where they create lactic acid, essential for producing cheese. Various types of bacteria can be used to make cheese, and some cheeses require several different bacteria to give them a particular flavor. Smith (p 21) says that Swiss cheese is made by adding Propionibacter shermani and other cultures to milk after it has been warmed. If the cheese in question is Swiss Emmental, the milk is not pasteurized.

Propionibacter shermani is one of the three types of bacteria used to make Swiss cheese, and it's responsible for the cheese's distinctive holes. Once P. shermani is added to the cheese mixture and warmed, bubbles of carbon dioxide form. These bubbles become holes in ...