Studies This is how the holes in Swiss cheese are made

Swiss researchers solve the mystery around the holes in the Emmentaler
How do the holes get into the cheese? This question has occupied researchers for decades. Dominik Guggisberg from the agricultural research institute Agroscope in Bern and his team were able to solve the puzzle recently. As they report in the journal "International Dairy Journal", the finest hay products in the milk are responsible for the holes. In addition, the researchers came to the secret of the "hole shrinkage" in cheese on the track.

Hay particles in the milk are responsible for the holes in the cheese
The Emmentaler puzzle is solved. After decades of research, Swiss scientists have succeeded in elucidating this great national mystery. According to this, the smallest hay particles in the milk cause the holes in cheeses such as Appenzeller or Emmentaler.

The mystery of the holes in the cheese is revealed. (Image: Xavier / fotolia.com)

As part of their study, Guggisberg and his team produced eight different Emmentalers from filtered, clean milk, which the researchers mixed with lactic acid bacteria and varying amounts of hay powder. During maturation, they documented the growth of the holes in the cheese by computer tomograph between day 30 and until the end on day 130. They also took measurements of fat, water, acid and gas content at the end of ripening. As it turned out, there were more holes in the Emmentaler, the more hay was contained in the milk.

Carbon dioxide can not escape from the cheese due to hay products
"The hay serves as a starting point for the carbon dioxide that is formed during the maturation of the cheese by the bacteria," Guggisberg said in an interview with the news magazine "Spiegel Online". Decisive are the capillaries, tiny tubes, in the hay products, which are only a few microns in size. The gas penetrate into these cavities and push the holes in the cheese. "The resistance for the gas is smaller there than in the rest of the cheese," explains study leader Daniel Wechsler to the magazine. Without the hay particles, the carbon dioxide evaporates, so that no holes can be formed. "You can imagine that, like a balloon: In the beginning, the inflation is particularly difficult. When the beginning is made, it's easier. "

The secret to "hole shrinkage" in the cheese is revealed
The researchers revealed another secret about Swiss cheese. For years, a "hole shrinkage" has been observed in the cheese. So far, however, it was unclear how it comes to this development. "While in the Emmentaler, for example, there used to be too many holes earlier in the winter, in the last 10-15 years cheese has increasingly been showing too economical perforation, what has been called" hole shrinkage "," Agroscope reports. "This phenomenon has been attributed to improved milking techniques and the associated, ever cleaner milk."

Guggisberg and his team have now found out that it's mainly the hay products that determine the number of holes in the cheese. Hay dust, especially during traditional milking in the barn, gets into the milk. By contrast, modern milking machines drain the milk so cleanly that it is barely exposed to external influences. "These technical improvements in milking technology have reduced the risk of unwanted microbial contamination while also reducing the entry of microscopic hay particles into the milk," the statement said. "As a result, fewer" hole attachment points "have been formed in the cheese."

According to the researchers, with the help of these new findings, the number of holes in the cheese can be controlled "almost at will" in the future.