how do you get holes in swiss cheese

The characteristic holes in Swiss cheese, also known as "eyes," are formed by carbon dioxide gas bubbles produced during the fermentation process. Here’s a simplified explanation of how they are created:

1. Bacterial fermentation: Swiss cheese is made using a type of bacteria called Propionibacterium freudenreichii. These bacteria are added to the cheese milk and help to convert the lactose (milk sugar) into carbon dioxide gas.
2. CO2 production: As the bacteria ferment the lactose, they produce carbon dioxide gas as a byproduct. This CO2 gets trapped in the cheese.
3. Gas bubbles: The trapped CO2 forms small gas bubbles within the cheese. These bubbles are initially tiny, but they grow larger as the fermentation process continues.
4. Eye formation: As the cheese ages and ripens, the gas bubbles expand and merge, creating larger holes or "eyes" within the cheese. The eyes can range in size from a few millimeters to several centimeters in diameter.
5. Enzymatic activity: The enzymes present in the cheese, such as proteases and lipases, help to break down the cheese’s protein and fat molecules, creating a network of tunnels and channels that allow the CO2 to escape. This process contributes to the formation of the characteristic holes.

Factors that influence the formation of holes in Swiss cheese include:

• Type of bacteria: The specific type of bacteria used in the cheese-making process can affect the size and distribution of the holes.
• Aging time: The longer the cheese is aged, the more time the CO2 has to accumulate and form larger holes.
• Temperature and humidity: The temperature and humidity conditions during the aging process can influence the rate of CO2 production and the size of the holes.
• Cheese-making techniques: The cheese-maker’s techniques, such as the amount of bacteria added, the temperature of the cheese milk, and the frequency of turning the cheese, can also impact the formation of holes.

The unique combination of bacterial fermentation, CO2 production, and enzymatic activity creates the characteristic holes that make Swiss cheese so recognizable and delicious!