Swiss researchers solve the puzzle about the holes in the Emmental
Do you know how the holes in the cheese are made? There are many theories about it, but no precise proof has ever been found. Dominik Guggisberg from the agricultural research institute Agroscope in Bern and his team were able to solve the riddle. They reported in the specialist journal "International Dairy Journal". Tiny hay particles in the milk are responsible. The scientists also uncovered the secret of "hole loss" in cheese.
Hay particles in the milk are responsible for the holes in the cheese
The Emmental riddle has been solved. After decades of research, Swiss scientists succeeded in solving this great national mystery. The smallest hay particles in the milk cause the holes in cheeses such as Appenzeller or Emmentaler.
As part of their study, Guggisberg and his team produced eight different Emmentals from filtered, clean milk, which the researchers mixed with lactic acid bacteria and different amounts of hay powder. During ripening, they documented the growth of the holes in the cheese using a computer tomograph between day 30 and until the end of day 130. They also carried out measurements of the fat, water, acid and gas content at the end of ripening. As it turned out, the more hay there was in the milk, the more holes there were in the Emmental.
Carbon dioxide cannot escape from the cheese through hay particles
"The hay serves as a starting point for the carbon dioxide that is formed by the bacteria when the cheese matures," said Guggisberg. The decisive factors are the capillaries, tiny tubes in the hay particles, which are only a few micrometers in size. The gas penetrates these cavities and presses the holes in the cheese. “The resistance to the gas is lower there than in the rest of the cheese,” explains study director Daniel Wechsler. Without the hay particles, the carbon dioxide evaporates so that no holes can be formed. “You can imagine it like a balloon: In the beginning it is particularly difficult to inflate. Once the start is made, it is easier. "
The secret of “hole loss” in cheese has been revealed
The researchers revealed another secret about Swiss cheese. A "hole loss" in cheese has been observed for years. So far, however, it has been unclear how this development will come about. "While, for example, there were previously too many holes in the Emmental valley in winter, cheese had increasingly been perforated too sparingly in the past 10-15 years, which was referred to as" hole loss ", reports Agroscope in a message. "This phenomenon has been attributed to improved milking technology and the associated, ever cleaner milk."
Guggisberg and his team have now found that it is mainly the hay particles that determine the number of holes in the cheese. Hay dust gets into the milk especially during traditional milking in the barn. Modern milking machines, on the other hand, draw the milk so cleanly that it is hardly exposed to external influences. "These technical improvements in milking technology have reduced the risk of undesirable microbiological contamination, but at the same time also reduced the entry of microscopic hay particles into the milk," the statement continues. "As a result, fewer" holes "in the cheese were formed."
According to the researchers, this new knowledge can be used to control the number of holes in the cheese “almost at will” in the future. (sb)