how are the holes made 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 step-by-step explanation of how they’re made:
- Cheese production: Swiss cheese is made from cow’s milk, which is heated and mixed with rennet (an enzyme) to separate the curds (solid parts) from the whey (liquid parts).
- Fermentation: The curds are then transferred to a cheese mold, where they undergo fermentation. During this process, bacteria like Propionibacterium freudenreichii, which are naturally present in the cheese or added during production, start to break down the lactose (milk sugar) in the curds.
- Carbon dioxide production: As the bacteria ferment the lactose, they produce carbon dioxide gas as a byproduct. This CO2 gets trapped in the cheese, forming bubbles.
- Bubble growth: The bubbles grow in size as more CO2 is produced, and they start to move upward through the cheese. As they rise, they create channels and holes in the cheese.
- Eye formation: The bubbles eventually reach the surface of the cheese and pop, leaving behind a hole or "eye." The size of the holes can vary depending on factors like the type of cheese, the aging process, and the bacteria used.
- Aging process: The cheese is then aged, which allows the holes to develop further and the flavor to mature. During this time, the cheese may be turned and rubbed with salt or brine to prevent mold from growing.
It’s worth noting that not all Swiss cheeses have holes. The size and frequency of the holes can vary depending on the specific type of cheese, such as:
- Emmental: Known for its large holes, which can be up to 1 inch (2.5 cm) in diameter.
- Gruyère: Has smaller holes, typically around 0.2 inches (5 mm) in diameter.
- Sbrinz: A Swiss cheese with very small holes or no holes at all.
The holes in Swiss cheese are not only a characteristic feature but also contribute to the cheese’s flavor and texture. They allow oxygen to enter the cheese, which helps to develop the flavor and aroma during the aging process.
