Say "Cheese"!

Have you ever wondered why or how Swiss cheese has holes?

Propionibacter shermani is one of the three types of bacteria used to make Swiss cheese. It is what is responsible for the cheese's distinctive holes. Once this bacteria is added to the warm cheese mixture, bubbles of carbon dioxide form and are what will eventually to become the holes or "eyes" in the cheese. Cheesemakers can control the size of the holes by changing the acidity, temperature, and curing time of the mixture.

The larger the eyes in a Swiss cheese the more pronounced its flavor. This is because the same conditions that lead to large holes (longer aging or higher temperatures) also give the acting bacteria and enzymes more time to produce flavor.

Larger holes do not slice well and come apart in mechanical slicers. Leave it to the U.S. Department of Agriculture (USDA) to create guidelines that regulate the hole size of domestically produced Swiss cheese! All of this to help the cheese have less problems in slicing.