Did you know why Swiss cheese have holes?

A Swiss agricultural institute determined that the famed holes in cheeses like Emmentaler and Appenzeller are caused by microscopic bits of hay dust. These “microscopically minute hay particles” help generate the holes in traditional Swiss cheese kinds as milk matures into cheese.

According to the government-funded Agroscope institute, the switch from traditional milking procedures in barns to fully-automated, industrial milking systems has resulted in a decrease in holes over the previous 15 years.