Processed cheese is natural cheese that has been melted, blended with emulsifying salts and other ingredients, and reformed into a smooth, uniform product designed to melt easily and last longer on the shelf. It was first patented by James L. Kraft in 1916, and the U.S. government began purchasing it in tins for soldiers during World War I the following year. That military demand helped launch what became one of the most widely consumed cheese products in the world.
How It Differs From Natural Cheese
Natural cheese is made by curdling milk, draining the whey, and aging the result. Processed cheese starts where natural cheese ends. Manufacturers take one or more varieties of finished natural cheese, grind them into small uniform pieces, then melt and blend them with added ingredients to create something with a completely different texture and melting behavior. The result is smoother, more consistent, and far more shelf-stable than any natural cheese it was made from.
Beyond the cheese base, a typical processed cheese product contains emulsifying agents, water, salt, acidifying agents, artificial coloring, and sometimes artificial flavors or spices. The emulsifying salts are the key ingredient that makes the whole thing work, and they deserve their own explanation.
Why It Melts So Well
In natural cheese, the protein (casein) is bound tightly to calcium, forming a rigid gel structure. Fat sits trapped within that structure, but when you heat natural cheese too aggressively, the fat separates and pools into a greasy puddle. This is why a slice of cheddar on a burger can turn oily instead of creamy.
Emulsifying salts, typically sodium phosphate or sodium citrate, solve this problem through a simple ion swap. They pull calcium away from the casein and replace it with sodium. This transforms the rigid protein gel into a flexible, soluble form that disperses evenly through the mixture. Once freed, the casein proteins coat the surface of fat droplets, keeping them suspended in a stable emulsion rather than letting them separate. The result is a cheese that melts into a smooth, creamy liquid every time, which is exactly why it became the default for cheeseburgers, grilled cheese sandwiches, and cheese sauces.
How It’s Made
Production begins with quality inspection. Incoming natural cheese is evaluated for moisture, acidity, and overall quality. Workers trim off rinds and any damaged areas, then grind the cheese into small, uniform pieces. Consistent size matters here because it ensures even heat transfer and better blending.
The ground cheese goes into a steam-jacketed cooker or continuous processing system. Ingredients are added in a specific sequence: emulsifying salts first, then liquids like water or milk, then dry ingredients last to prevent clumping. The mixture is heated to between 70 and 85°C (158 to 185°F) while being continuously stirred. This heating melts the cheese, activates the emulsifying salts, and kills harmful bacteria.
Constant agitation during heating prevents hot spots and creates the smooth, glossy texture that defines the product. The entire cooking process typically takes just 4 to 8 minutes. Operators watch for visual cues: a glossy surface and the complete disappearance of visible cheese particles signal that the batch is ready. From there, the hot mixture is poured into molds, sliced into individual portions, or packaged in jars or squeeze tubes depending on the product format.
What the Label Actually Means
The FDA regulates what can be called “pasteurized process cheese” under strict standards. To earn that label, the product must contain at least 47% fat by dry weight and no more than 43% moisture in most cases. These thresholds ensure a minimum amount of real cheese in the product.
Products that don’t meet these standards get downgraded to different legal names. “Pasteurized process cheese food” contains less cheese and more added ingredients. “Pasteurized process cheese product” has even less cheese and can’t legally use the word “cheese” without qualifiers. If you’ve ever noticed that some packages say “cheese product” or “cheese slices” instead of just “cheese,” this is why. Reading the exact wording on the label tells you roughly how much real cheese is inside.
Sodium: The Biggest Nutritional Gap
The most significant nutritional difference between processed and natural cheese is sodium. A study published in the Journal of Dairy Science measured sodium levels across retail cheese products in the United States and found that processed cheese averaged 1,242 mg of sodium per 100 grams. Natural cheddar averaged 615 mg per 100 grams. That means processed cheese contains roughly twice the sodium of the natural cheese it was made from.
The range is wide, too. Some processed cheese brands tested as high as 1,590 mg per 100 grams, while others came in around 936 mg. For context, a single standard slice of processed American cheese (about 21 grams) typically delivers 250 to 350 mg of sodium, which is 10 to 15% of the recommended daily limit in one slice. If you’re stacking two or three slices on a sandwich, the sodium adds up quickly.
The Phosphate Question
The emulsifying salts in processed cheese are phosphate-based, and the type of phosphorus they contain behaves differently in your body than the phosphorus naturally present in food. Phosphorus bound to animal proteins is absorbed at a rate of about 40 to 60%. Plant-based phosphorus, locked up in compounds called phytates, is absorbed even less efficiently.
Inorganic phosphorus, the kind added to processed foods including processed cheese, can be absorbed at rates approaching 100%. For most healthy people, the kidneys handle this extra phosphorus without trouble. But for anyone with reduced kidney function, the body struggles to clear excess phosphorus from the blood, which can contribute to serious complications over time. This is one reason dietitians often flag processed cheese specifically when counseling people with kidney disease.
Where Processed Cheese Works Best
Processed cheese exists because it solves practical problems that natural cheese cannot. It melts predictably at a wide range of temperatures, making it ideal for fast-food operations where consistency matters across thousands of locations. It resists separating when reheated, which is why it works in cheese sauces, dips, and casseroles that natural cheese would break down in. Its shelf life, measured in months rather than weeks, reduces waste for both retailers and consumers.
It also costs less. Because manufacturers can blend younger, less expensive cheeses together and extend them with added water and other ingredients, the final product hits a lower price point than aged natural cheese. For feeding large groups or stretching a grocery budget, this matters. The tradeoff is a milder flavor, higher sodium, and a list of added ingredients that natural cheese doesn’t need.