For centuries, the holes in Swiss cheeses like Jarlsberg were a mystery. That is, until about 1917 when a study concluded that they were the natural result of the carbon dioxide emitted by cheese bacteria fermenting. Essentially, gas was getting trapped in cheese, expanding, and making the holes “Swiss” cheese is known for. Humanity accepted this as fact and we went on our way enjoying copious amounts of Swiss cheese without concern for the past 100 years. Things were going fine.
Until the holes started disappearing.
Sure, a lot has changed about the way cheese has been made since the first Swiss cheese wheel, but bacteria hasn’t suddenly decided to stop producing carbon dioxide. So what could explain the recent phenomenon of smaller, more infrequent cheese holes?
It turns out the aforementioned study wasn’t quite correct, and it took some of the changes in the way we make cheese to reveal that. As you can imagine, modern advancements in milk production have allowed for cleaner mass production and delivery of cheese. Our modern machines have replaced the traditional farmer on a stool with a metal bucket, which has removed a lot of the natural environment from milk. And when we say “natural environment,” we mean hay.
Swiss researchers have concluded that the holes in cheese were actually the result of hay particles, naturally introduced to the sourced milk via the barnyard environment. It turns out the cost of our cleaner, safer methods of cheese production includes some of the charming quirks of Swiss cheese. Of course, if consumers demand holes in their cheese, cheesemakers can start adding hay particles to the cheese.
Whether that will become necessary can be the new mystery we obsess over.