After a century of speculation, scientists have finally figured out why Swiss cheese is adorned with its signature holes (and, no, contrary to popular belief, there are no mischievous mice involved).
A new report from Swiss research institution Agroscope fingers small bits of hay as the culprit. However, as modern technology has vastly improved the sanitation behind cheesemaking, the amount of hay finding its way into milk has decreased. As such, the size and amount of holes in cheese has also gone down over the past two decades.
"It's the disappearance of the traditional bucket" that is making a difference, according to Agroscope spokesman Regis Nyffeler.
A 1917 study published by William Clark originally attributed the holes to carbon dioxide released by bacteria in milk.
After about a century of research, scientists in Switzerland have finally solved the mystery of the holes in Swiss cheese.
Despite what you may have been told as a child, the holes are not caused by mice nibbling away inside cheese wheels.
Experts from Agroscope, a state centre for agricultural research, said the phenomenon – which marks famous Swiss cheeses such as emmental and appenzell – was caused by tiny bits of hay present in the milk and not bacteria as previously thought.
They found that the mystery holes became smaller or disappeared when milk used for cheesemaking was extracted using modern methods.
“It’s the disappearance of the traditional bucket” used during milking that caused the difference, said Agroscope spokesman Regis Nyffeler, adding that bits of hay fell into the milk and then eventually caused the holes.
Agroscope said the mystery had been studied since at least 1917 when American William Clark published a detailed research and came to the conclusion that it was caused by carbon dioxide released by bacteria present in the milk.
Agroscope scientists noted that Swiss cheeses had fewer holes over the past 10 to 15 years as open buckets were replaced by sealed milking machines that “completely did away with the presence of tiny hay particles in the milk”.
