Real Cheese Product—The Miracle of Milk Protein Concentrate | culture: the word on cheese
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Real Cheese Product—The Miracle of Milk Protein Concentrate

milk protein concentrate

Hold on to your blue boxes and your viscous yellow liquids! This blog series will take you on a wild ride through the history, politics, science, and culture of processed cheese, including the origins of factory cheese, the rise of James L. Kraft, and the miracle of milk protein concentrate. I hope you didn’t miss last week’s thrilling conclusion to the Kraft Keepsakes two-parter, but if you did, you can read all about Kraft’s Macaroni & Cheese Dinner here.

Here we are, ladies and fellas, at the penultimate post of this excellent adventure deep into the historic and scientific nooks and crannies of the process cheese world. I bet you’re feeling pretty sure of yourselves—you know all about Jesse Williams and the first cheese factoriesthe deadly specter of filled cheese, and the coronation of Kraft as premier cheese king. But brace yourself, readers, because your minds are going to expand so significantly with new and crazy knowledge it will feel like a cheese explosion. Let me introduce to you the wünderproduct of the late twentieth century process cheese industry: milk protein concentrate, made possible by the miracle of ultrafiltration technology.


Ultra-filtra-whatsit? Lemme explain: The inexorable march of capitalist progress (to which process cheese pretty much owes its entire existence) stepped in once again in the form of Koch Membrane Systems, a company owned by none other than the Koch brothers, of political conservative activism fame. In its constant research to make plastics better, stronger, and faster (okay, maybe not faster), Koch Membrane Systems came up with a very sophisticated, complex membrane known as polyethersulfone. This membrane was so fine it could separate molecules. Finally, at this moment, scientists working for the Koch brothers achieved a feat cheesemakers had been aiming at since they first started skimming cream from milk and replacing the fat with lard: Koch separated milk into its component molecular parts.

Access to these individual milk components opened up a whole new world in the dairy industry. For instance, whey protein and caseinate allowed food scientists to completely remove the fat from milk, giving rise to low-fat and fat-free products for the first time. But the innovation most important to the process cheese industry was milk protein concentrate, or MPC.

MPC is essentially milk stripped of all superfluities. Gone are fats, liquids, bacteria, sugars, and minerals—all that is left is protein, plus whatever managed to get through the polyethersulfone membrane. The result is a dry, powdery, protein-packed substance that has some very attractive qualities for process cheesemakers. For one, it can act as a thickening agent, allowing a thinner yogurt product, for example, to take on the appearance of the real deal with just a sprinkling of the stuff. But what is even more amazing about MPC is that it is cheap (any kind of milk can be used to arrive at more or less the same product) and it is consistent (always the same high level of protein). It was toward these two qualities that the Kraft corporate behemoth turned its profiteering eyes.


In the mid-’90s, Kraft realized that it could cut a whole lot of costs and maintain a more consistent product if they phased milk protein concentrate into their ingredient list for some of their cheese products, American Singles being the most notable. In non-process cheese and even the process cheese of the time, protein levels could vary extraordinarily from batch to batch. But with MPC, Kraft food engineers can tailor the protein levels to be the same in every batch, so every package of American Singles had the same taste and same golden sheen. Plus, MPC was easy to store and could last for over two years.

Kraft began introducing MPC into its products, and, the American cheese-eating public being the undiscerning consumers that they are, nobody noticed. It was not until 2002, during a routine inspection of Kraft cheese factories in the Midwest, that the FDA just happened to notice there was an extra ingredient on those process cheese packages: milk protein concentrate.

Now, going back to the very first post of this series, the FDA has strict rules for what qualifies as an official cheese food. The standard for “pasteurized process cheese food,” which was the category American Singles fell under, did not allow for any ingredients along the lines of MPC. In the rabble-rousing words of the FDA, the cheese foods Kraft had been peddling were being “represented as foods for which standards of identity have been prescribed by regulation, and the use of milk protein concentrate in these products does not conform to the standards.”

What could Kraft do? The company could have stopped using milk protein concentrate. It could have lobbied the US government to change FDA regulations on what exactly constituted a cheese food. But instead, Kraft made a historic decision that reflects the growth of the process cheese world and American consumers’ opinion of process cheese: Kraft just changed the product description. American Singles were no longer a pasteurized process cheese food, which had a number of regulations tacked to it; they became a pasteurized prepared cheese product, which was completely undefined by the FDA.


American consumers remained unfazed, and most probably noticed nothing different about their American Singles besides a minor typographical change in the small type beneath the impressive and engaging graphic of a slice of wholesome cheese and a big glass of milk.

The dairy-consumption wheel o’ life made another turn, and America stood gleefully watching the dawn of a new process cheese world. Consumers had enabled Kraft’s cheese innovations for almost a century, and now they could smother themselves in the gooey process cheese of their own making.

Is there any bright, shining hope at the end of this tunnel? Tune in for next week’s installment of real cheese product: Annie’s Mac & Cheese and the rise of “natural” foods!

Grant Bradley

Grant Bradley is culture's former web editor and never ceases to thank his nameless human ancestor who figured that leaving some milk around for a while and then eating it was probably a great idea. Raised on California’s Central Coast, educated in the Pacific Northwest, and transplanted to New England, Grant likes to write, edit, and code things.

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