American cheese was not invented in America. The technology behind it originated in Switzerland in 1911, when two scientists figured out how to melt cheese into a smooth, stable mass. A Canadian-born entrepreneur living in Chicago then adapted and patented the process, and two World Wars turned the product into a household staple across the United States.
The Swiss Invention
In 1911, Walter Gerber and Fritz Stettler discovered that heating shredded Emmentaler cheese with sodium citrate (a salt derived from citric acid) produced something remarkable: the cheese melted into a uniform, creamy mass instead of separating into greasy clumps. This was the first processed cheese. The sodium citrate worked by pulling calcium away from the protein structure in the cheese, which freed the proteins to spread out and coat tiny fat droplets evenly. The result was a smooth, stable product that behaved nothing like the stringy, oily mess you’d normally get from melting natural cheese.
James L. Kraft’s Patent
James L. Kraft, a Canadian who had moved to Chicago to sell cheese from a horse-drawn wagon, took the concept further. In 1916, he received a U.S. patent for a process that solved a different but related problem: making cheddar cheese last indefinitely without spoiling.
The challenge was that cheddar falls apart when heated much above its melting point. The fats and proteins separate, and the cheese loses what Kraft’s patent called its “true cheesy character.” His breakthrough was continuous stirring. By cutting cheese into small pieces, placing them in a steam-jacketed kettle, and agitating the mass constantly while raising the temperature to about 175°F for fifteen minutes, Kraft could sterilize the cheese without destroying its texture. The result could be sealed in cans and shipped anywhere without refrigeration.
This wasn’t the same as Gerber and Stettler’s emulsified cheese. Kraft’s original process relied on mechanical agitation rather than chemical salts. But the two approaches eventually merged as manufacturers adopted emulsifying salts alongside Kraft’s heating and mixing techniques to produce the processed cheese we know today.
How Two Wars Made It Famous
Processed cheese had one quality the military loved: it traveled well. Cheese was a convenient, compact way to ship dairy nutrition to soldiers, and Kraft became a major supplier to the U.S. government during both World Wars. During World War II, Kraft sold 50 million boxes of its macaroni and cheese alone, a product introduced in 1937 during the Depression but perfectly suited to wartime rationing.
The war effort also pushed the science forward. In 1943, a USDA scientist named George Sanders developed the first real cheese powder. When the war ended in 1945, the military sat on enormous stockpiles of powdered and processed cheese. The government sold these surplus supplies to private companies for almost nothing. Kraft, Frito, and others found creative uses for the cheap ingredients. In 1948, the Frito company coated puffed cornmeal pieces with dehydrated cheese and created Cheetos.
Millions of returning soldiers had eaten processed cheese overseas and kept buying it at home. By the late 1940s, processed cheese was embedded in American kitchens.
The Individually Wrapped Slice
The product most people picture when they hear “American cheese” is the individually wrapped single slice. That packaging innovation didn’t come from Kraft. An engineer named Arnold Nawrocki, working for the Clearfield Cheese Company, developed a machine to wrap individual slices in August 1956. Kraft didn’t introduce its own individually wrapped slices until 1965, but the brand became so dominant that Kraft Singles became nearly synonymous with the product.
What’s Actually in It
Modern American cheese starts with real cheese, typically cheddar or colby, which is cut up and combined with emulsifying salts, additional dairy ingredients like cream, butter, whey protein, or milk powder, and then heated and mixed into a uniform mass. The emulsifying salts do the same job sodium citrate did back in 1911: they pull calcium out of the protein network in the cheese, allowing the proteins to spread out and wrap around fat droplets. This creates the signature meltability, that perfectly even, glossy melt on a burger that natural cheese can’t quite replicate.
Industrial production typically involves blending all ingredients in a cooker, mixing at high speed for about three minutes, then heating under vacuum to around 170°F before raising the temperature to 185°F and holding it there for two minutes. The hot product is packaged immediately.
Why the Label Matters
Not everything sold as “American cheese” is the same product. U.S. federal regulations define three distinct categories based on composition, and the differences are significant.
- Pasteurized process cheese is the real deal. It must contain no more than 43% moisture and at least 47% fat in its solid portion. It’s made entirely from comminuted and blended natural cheeses plus emulsifying agents.
- Pasteurized process cheese food allows additional dairy ingredients like whey and milk powder. Moisture can reach 44%, and the fat minimum drops to 23%. At least 51% of the finished product by weight must come from actual cheese.
- Pasteurized process cheese product falls outside both of those standards. It contains more moisture, more additives, and less actual cheese. This is the category many individually wrapped singles fall into, which is why some brands can’t legally use the word “cheese” on the front of their packaging.
If a package says “cheese product” rather than “cheese,” you’re getting something with considerably less cheese and more filler ingredients.
American Cheese Today
American cheese is losing ground. U.S. cheese consumption overall hit record levels in 2023, with the average person eating more than 42 pounds per year. But American cheese sales have dropped nearly 5% in early 2025, while mozzarella, colby jack, cheddar, and European-style varieties like Gouda and Havarti are all growing. The same convenience that made processed cheese revolutionary in 1916, its long shelf life and easy melting, matters less in an era of widespread refrigeration and a consumer preference for less processed foods.
Still, for a product invented by Swiss scientists, perfected by a Canadian immigrant, and popularized by two World Wars, American cheese earned its name the same way many American things do: not by being born here, but by becoming inseparable from the culture that adopted it.