Why does Swiss cheese have holes?

+72 votes
asked Dec 19, 2018 in Food & Drink by Justine (890 points)
edited Jan 2, 2019 by Kris
Is it mice nibbling through the big wheel of cheese? I grew up watching “Tom & Jerry”. I had that impression since I was young that a mouse like Jerry would munch into the cheese and makes these tiny rooms. All that somehow helps to develop the flavor and gives the signature look. I know that sounds dumb, so I would like to know what actually form these holes in Swiss cheese?

2 Answers

+26 votes
answered Apr 17, 2019 by Tanneal (830 points)
edited Apr 22, 2019
Like all cheese, milk is cultivated with bacteria and turns into cheese. But unlike all cheese, they don’t tend to have holes in them. It was initially thought that these bacteria create these air holes. The bacteria give off enough carbon dioxide and form these bubble in the cheese, once fermented, these holes would stay as part of the hole of the Swiss cheese.

The new theory, however, comes from tiny specks of hay that was accidentally collected while milking a cow. These hay particles weaken the cheese structure and allow air to accumulate into it. With the modern milking method, less flecks of hay is found in the milk that later made into the cheese, and these cheese end up with less holes. So there is a correlation of higher numbers of little hay particles to a higher number of holes in Swiss cheese, or “eyes” as the cheese farmers call it. It could also be the combination of both bacteria and the hays theory. Whatever the case is, they still taste delicious!
commented Jul 16, 2015 by Pualehua (710 points)
An interesting reason why does swiss cheese have holes
+8 votes
answered Aug 2, 2019 by Christy (970 points)
edited Aug 12, 2019
Here’s an interesting fact about the holes in cheese you may not know. In the past, some cheese slicers met quite a number of troubles that are caused by the holes in Swiss cheese, so in 2000 FDA came out with a regulation that holes in Swiss cheese need to be between 3/8 and 13/16 of an inch in diameter.
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