The culinary science behind the perfect, unctuous melt of American cheese
Ever wonder why American cheese melts into a silky pool while natural varieties turn into a greasy, lumpy mess? The secret lies in a precise chemical transformation that turns traditional dairy into a stable, homogeneous, and incredibly versatile plastic-like substance.
To understand American cheese, one must first understand the challenge of heating dairy. In natural cheeses, heat causes fats to separate from the solid structures, leaving behind a pool of oil and a stringy residue. American cheese avoids this through a process of pulverizing, heating, and mixing real cheese with specific additives to create a substance that is physically plastic—meaning it can be easily molded or shaped.
The magic happens via emulsifiers. These are chemical agents that allow two normally incompatible liquids, such as oil and water, to remain blended. In cheese, which consists of oil-soluble substances and water-soluble proteins and minerals, emulsifiers work by grabbing fat globules and suspending them evenly throughout the watery solution. This prevents the separation that usually occurs during melting. Common emulsifying agents used in this process include various phosphates, such as monosodium phosphate or trisodium phosphate, as well as citrates like sodium citrate.
Beyond emulsifiers, the composition can include acidifying agents like vinegar or lactic acid, mold inhibitors such as sorbic acid, and additional fats like anhydrous milkfat. While the FDA allows for various additives, the legal definition of 'pasteurized process cheese' requires that the final product maintains moisture, fat, and pH levels similar to the original cheese ingredients. If the base is cheddar or Colby, it is labeled American cheese. However, if the cheese content is diluted by other ingredients, the label may shift to more vague terms like 'cheese food' or 'cheese product,' though these must still contain at least 51% actual cheese.
Source: What Is American Cheese Really Made Of?
