Holey Swiss cheese? These days, not so much. If you’ve been wondering why your Swiss cheese — your Emmentaler or Appenzeller — has fewer of its iconic “eyes,” agricultural researchers in Switzerland have finally brought you your answer: Blame cleanliness.
As far back as 1917, scientists were considering the holes in Swiss cheese and concluding that they were formed by bacteria that produced carbon dioxide, according to Agroscope, the Swiss government’s agricultural research institute. Researchers didn’t know much, however, about what the bacteria were and how they got there in the first place.