The reason behind the holes in Swiss cheese is the work of bacteria. To form cheese from milk, we supplement milk with bacteria. This bacteria added to milk generates lactic acid that is essential for synthesizing cheese. Different cheese types are created by various bacteria that gives them different flavors.
Propionibacter shermani is one of the types of bacteria that can form cheese. Swiss cheese, especially, has holes in it. If this bacteria is mixed into the cheese, and heated a little, carbon dioxide is released. The released gas creates holes in the cheese. The size of the holes can be altered by changing the acidity, temperature and time of its preservation. These holes are called ‘eyes’, and a Swiss name is allocated for this cheese – Emmentaler.
The US Department of Agriculture has released a new guideline regarding the making of Swiss cheese. The USDA, in its guidelines, has suggested decreasing the size of the holes in Swiss cheese by half. But many people were not satisfied by this rule. Cheese is also made in other parts of the world by using the same bacteria, and is named Swiss cheese. But the real ‘Swiss cheese’ or ‘Emmentaler’ is only made in that particular region of Switzerland
Some organizations in Switzerland are specialists in synthesizing Lorraine Swiss, known as Baby Swiss. This has smaller holes than Emmentaler, as it is not preserved for very long. If the cheese is cured for a long time, then it develops larger holes. In some cheeses, carbon dioxide moves through it and escapes at the skin’s edge. But in Swiss cheese, as it is made dense and thick, there is no possibility for the carbon dioxide to leave through the edge of the cheese.
Cheese with less age has smaller holes in it, while cheese with a greater age has larger holes, and a delicious flavor.