Why Does Swiss Cheese Have Holes?

(Last Updated On: March 3, 2020)

Why Does Swiss Cheese Have Holes?

Be it at the market, on TV, or a in comic (or maybe something else entirely), you’ve probably seen the iconic image of a cheese triangle dotted with holes. You probably now recognize that specifically as Swiss cheese, where once as a child you may have thought it to be simply all cheese. So let’s investigate this age-old image, and get to the heart of Swiss cheese; or rather, fill the hole in it. Let’s explore why Swiss cheese has holes in the first place.

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The Cheese Has Eyes

Before we get into what makes the Swiss holes happen, we should get into the terminology. Because yes, there are designations for your favorite cheese.

So Swiss cheeses are made of cow milk, originating from Switzerland. These are all things we should know from the get-go because it’s cheese and has “Swiss” in its name. Anyway, the cheese we’re looking at specifically is Emmental cheese, which is also a Swiss cheese (it started popping about in 1292). This cheese is named after the Emmental, which is a river valley. But do take note that not all cheeses from Switzerland have holes.

Oh, and speaking of holes–the holes in cheese are actually called eyes. Cheeses without the holes are referred to as blind. Go figure.

Why Does Swiss Cheese Have Holes?

Original Theory

Traditionally, there has been one theory that people tend to agree on when it comes to the holes in Swiss cheese. But it turns out there are other competing theories that came about more recently, but we’ll explain.

Way back in 1917, William Mansfield Clark coined a theory that lasted for a good while. Basically, the theory held that while the cheese was fermenting, bacteria would eat at it (this is true, it gives cheese its flavor thanks to lactic acid). While the bacteria were feasting, they would produce carbon dioxide. This gas would expand and displace the cheese, therefore creating our cheese eyes.

The New Theory

Relatively recently, however, Agroscope came forth with new research and a new theory about cheese development. By using CT scanners while the cheese was developing, it turns out Swiss cheese eyes are caused by little (microscopic) flecks of hay that get into the milk as it becomes cheese. These naturally create cavities and eventually you end up with the large eyes in your Swiss cheese.

But wait, there’s more–because there’s always more. Because the process by which we make cheese is becoming more and more automated, we’re getting fewer imperfections in the cheese making process. So there are fewer little hay flecks getting into the fermenting milk and fewer eyes being made in your Swiss cheese. Yes, eventually as we perfect the cheese making process, Swiss cheese will probably go blind. Take that for what you will.

Think you eat the most cheese? See how your dairy consuming habits stack up to the rest of the world here.

About the Author:

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Kyler is a content writer at Sporcle living in Seattle, and is currently studying at the University of Washington School of Law. He's been writing for Sporcle since 2019; sometimes the blog is an excellent platform to answer random personal questions he has about the world. Most of his free time is spent drinking black coffee like water.