how do they put holes in swiss cheese
The characteristic holes in Swiss cheese, also known as "eyes," are formed during the fermentation process by carbon dioxide gas produced by bacteria. Here’s a simplified explanation:
- Microbial fermentation: Swiss cheese, such as Emmental or Gruyère, is made using a type of bacteria called Propionibacterium freudenreichii. These bacteria are naturally present on the cheese or added during the cheese-making process.
- Lactic acid production: As the bacteria feed on the lactose (milk sugar) in the cheese, they produce lactic acid. This process causes the cheese to acidify and creates an environment that favors the growth of more bacteria.
- Carbon dioxide production: The Propionibacterium bacteria also produce carbon dioxide gas as a byproduct of their metabolism. This CO2 gas gets trapped within the cheese.
- Gas bubbles form: As the CO2 gas accumulates, it forms small bubbles within the cheese. These bubbles can range in size from small pinholes to large, rounded holes (eyes).
- Hole formation: The bubbles continue to grow as more CO2 is produced, eventually causing the cheese to expand and create the characteristic holes. The size and distribution of the holes can vary depending on factors like the type of cheese, aging time, and bacterial cultures used.
- Aging process: The cheese is aged, which allows the holes to mature and develop their characteristic shape and size. The aging process can last from several months to several years.
It’s worth noting that the holes in Swiss cheese are not just a result of chance or intentional manipulation. They are a natural consequence of the cheese-making process and the interactions between the bacteria, enzymes, and other factors involved in the production of this iconic cheese.
