The reason why Swiss cheese doesn’t have holes anymore | New York Post
Now you know.
The mystery of Swiss cheese and its disappearing holes has been solved: The milk’s too clean.
A Swiss agricultural institute discovered that tiny specks of hay are responsible for the famous holes in cheeses like Emmentaler or Appenzeller. As milk matures into cheese these “microscopically small hay particles” help create the holes in the traditional Swiss cheese varieties.
Now you know.