Swiss cheese gets its name simply from its country of origin: Switzerland. The cheese was originally developed in the Emmental valley of central Switzerland, where it’s known as Emmentaler (or Emmental). When it was exported to English-speaking countries like the United States, Canada, Australia, and New Zealand, people started calling it “Swiss cheese” as a shorthand reference to where it came from. In Europe, you’d still ask for Emmental at the cheese counter. “Swiss” just refers to the geography, not any official cheese name.
How Emmental Became “Swiss Cheese”
Cheesemaking in the Emmental valley goes back centuries. As dairies in the region grew, they began producing the cheese in large quantities and marketing it beyond Switzerland’s borders. English-speaking countries adopted “Swiss cheese” as a generic label for this style of pale, hole-filled, mild-tasting cheese. Over time, that label stuck so firmly that it became the default name in grocery stores across North America and the Pacific.
The shift from a specific regional product to a generic category is the key distinction. In Switzerland and across Europe, Emmentaler AOP is a protected designation that refers to cheese made in the Emmental region using traditional methods. In the United States, “Swiss cheese” is a broad category that can be made anywhere, by anyone, as long as it meets certain standards. The USDA even grades it: Grade A Swiss cheese must have well-developed, round or slightly oval eyes that are relatively uniform in size, with most holes measuring 3/8 to 13/16 of an inch in diameter.
What Makes the Holes (and Why They Matter)
The famous holes are central to the cheese’s identity and its name recognition. They form during a ripening stage that’s unique to Swiss-type cheeses. Early in production, starter bacteria convert the milk’s sugars into lactic acid. Then a second type of bacteria takes over, consuming that lactic acid and releasing carbon dioxide gas as a byproduct. Those CO2 bubbles get trapped inside the cheese as it firms up, leaving behind the characteristic round openings that cheesemakers call “eyes.”
This process also creates the cheese’s flavor. The same bacterial fermentation that produces gas also generates propionic acid and acetic acid, which contribute to the mild tanginess. The nutty, slightly sweet taste comes from a combination of small peptides, amino acids, and free fatty acids that develop as the cheese ages. Calcium and magnesium ions interacting with those peptides are specifically responsible for the sweetness, while the nuttiness traces back to compounds in the cheese’s fat.
Why the Holes Are Shrinking
Here’s something surprising: Swiss cheese holes have been getting smaller over the past few decades, and scientists finally figured out why in 2015. Researchers at Switzerland’s Agroscope institute discovered that the holes aren’t triggered by bacteria alone. Tiny particles of hay dust that naturally fall into raw milk during traditional farming act as “seeds” for bubble formation. Each microscopic particle gives the CO2 gas a starting point to collect around, eventually forming an eye.
Modern milking systems are far cleaner than they used to be. Techniques like microfiltration and centrifugation remove nearly all particulate matter from the milk before cheesemaking begins. This makes for more hygienic cheese, but it also strips out the hay particles that nucleate hole formation. The result is cheese with drastically fewer and smaller eyes. The researchers confirmed this by adding trace amounts of hay powder back into microfiltrated milk and watching the holes return in a dose-dependent pattern: more hay particles meant more eyes.
This finding explained a mystery that had puzzled Swiss cheesemakers for years. Their cheese was becoming denser and more uniform, which sounds like an improvement but actually counted as a quality downgrade in the traditional grading system, where well-formed eyes are a mark of proper ripening.
Swiss Cheese vs. Emmentaler
If you buy “Swiss cheese” in an American grocery store, you’re getting a domestically produced cheese inspired by the original but not bound by any of the traditional production rules. It’s typically younger, milder, and made with pasteurized milk. The holes tend to be smaller and more uniform because producers carefully control the bacterial cultures and aging conditions.
True Emmentaler AOP from Switzerland is aged longer, uses raw milk, and has a more complex, nuttier flavor profile. The wheels are enormous, sometimes weighing over 200 pounds, and the eyes are generally larger. The protected designation means the cheese must be produced in specific Swiss regions following established methods. You’ll pay more for it, but the difference in flavor is significant.
Other countries produce their own Swiss-type cheeses too. France makes Emmental de Savoie, and various European regions have their own versions. All share the same basic technique of using gas-producing bacteria during ripening, but differences in milk quality, bacterial strains, aging time, and local conditions give each version a distinct character. The American version that most people know as “Swiss cheese” sits at the milder, more approachable end of this spectrum.