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.

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.

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 the final product. Cheesemakers can control the size of the holes by changing the acidity, temperature, and curing time of the mixture. Incidentally, those holes are technically called "eyes".

A number of cheeses are marketed under the name of Swiss cheese. The true Swiss cheese is Swiss Emmental or Emmentaler, produced in a particular part of Switzerland. Emmental has a protected origin designation, which means that only cheese prepared in that area of Switzerland, and in a certain way, can be labeled Emmental. Swiss Emmental has the creamy texture and large holes most consumers associate with “Swiss cheese.”

Other holey cheese is made in various parts of the world and labeled as Swiss cheese because it uses the same bacteria and a similar fermentation practice. Some dairies also specialize in the manufacture of Lorraine Swiss, also known as baby or lacy Swiss. Baby Swiss has much smaller holes than Emmentaler, because the cheese is not allowed to age as long. The longer the cheese cures, the larger the holes will be.

But the air/cheese ratio will be changing soon. It seems Swiss cheese with big holes fouls up modern slicing machinery. So the industry is now asking that the regulations for Grade A Swiss be revised to make the average hole only three-eighths of an inch in diameter--one-quarter the area it is today. (Small-hole Swiss is now classified as Grade B, which commands a lesser price. Libertarians, needless to say, are frothing at the very idea of the government regulating Swiss cheese hole size.)

For many it just won't be the same. One nudnick on the Internet, showing the effects of too much consumer brainwashing, claims the best part of Swiss cheese is the holes: "If only there were more holes and they were bigger"! Come over to my house, bud, and I'll sell you some cheese that's all holes. The rest of you can console yourselves with the thought that you'll be getting more cheese and less thin air..

From ... AskYahoo.com