Why Does Swiss Cheese Have Holes?

There is a scientific reason why Swiss cheese has holes and it has nothing to do with rats nibbling on it.

Why Does Swiss Cheese Have Holes?
Swiss cheese has holes. (Photo by NastyaSense Sens via Pexels)

Some people think Swiss cheese is produced only in Switzerland because of its name. In spite of the name, the Swiss cheese that Americans eat is produced primarily in the United States and Canada. Over 297.8 million pounds are produced in the United States every year.

If you ask for Swiss cheese in countries such as Australia, Canada, New Zealand, and the United States, you will get the holey cheese you are familiar with. However, if you want Swiss cheese in the United Kingdom and Europe, you should ask for Emmental cheese that is named after the river valley in Switzerland where it was first produced in 1292.

You might have heard the joke that the holes in Swiss cheese are from rats nibbling on a block of cheese. This is not true at all. There is a scientific reason why holes appear in Swiss cheese.

The holes in Swiss cheese come from bacteria that turn milk into cheese. In fact, all cheese contains bacteria which aid in the process of the edible product that it turns out to be. Bacteria help produce curds that are pressed and soaked in brine inside of cheese molds. Then the cheese is left to ripen while it is stored between 72 and 80 degrees Fahrenheit. While the ripening process is taking place, bacteria release lactic acid. The bacteria also release carbon dioxide and form bubbles. The bubbles turn into air pockets that end up as the holes that we see.

Eyes in Swiss Cheese

Holes in Swiss Cheese (Photo by CCO Public Domain)

Holes in Swiss cheese are called "eyes." The cheese with the bigger holes or eyes have a more pronounced flavor. That's an indication that the bacteria had a longer time to act during fermentation. Swiss cheese with larger holes pose a problem for slicing machines because the slices fall apart. For that reason, officials in the cheese industry only give blocks of Swiss cheese with smaller eyes a Grade A stamp of approval.

Because bigger is not better in all situations, the size of the holes is controlled by cheese makers. Over the years, they have learned a lot about making Swiss cheese. Therefore, they know how to control the size of the holes by adjusting the acidity, temperature, and the length of ripening time.

When manufacturers first began making Swiss cheese, they thought the holes were imperfections until they discovered that it was the bacteria that contributed to the holes being in the cheese. They also discovered that not all Swiss cheese have eyes. Those without eyes are described as "blind."

Not the Most Popular Cheese

Even though Swiss cheese is healthy and delicious, it is not the most popular cheese in the United States. According to the United States Department of Agriculture (USDA), each American eats over 30 pounds of cheese a year. About 11.5 pounds of that is mozzarella and 9.6 of that number is cheddar. That's because those two types have more uses than Swiss cheese. Swiss cheese is not usually used to make macaroni and cheese which has become everybody's favorite comfort food. Swiss cheese is used primarily on sandwiches, on crackers, and in soups.

When you visit a sandwich shop such as Subway, you are usually asked which cheese you want on your sandwich. The restaurant has several kinds of cheese available, including Swiss cheese.

Varieties of Swiss Cheese

In the United States, there are two varieties of Swiss cheese:

  1. Baby Swiss cheese is made from whole milk and has small holes with a mild flavor.
  2. Lacy Swiss is made from low-fat milk. It also has small holes with a mild flavor.


  1. Do you like Swiss cheese?
  2. Have you ever seen Swiss cheese without holes or eyes? If so, the cheese is considered to be blind.

  3. Did you know that eating cheese can be as addictive as drugs?
fact or fiction
Margaret Minnicks
Margaret Minnicks
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Margaret Minnicks

Margaret Minnicks shares articles with readers all over the world. Topics include celebrities, royal family, movies, television, foods, drinks, health issues, and other interesting things. Thanks in advance for TIPS that are sent my way.

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