Cheese purists the world over exalt their mummified milk. Their silken Goudas and savory Emmentalers. Their fetid fetas and squeaky queso frescos. Their moldy Roqueforts and runny Camemberts. These disks of rotted dairy are the pinnacle of thousands of years of experimentation that began when a herdsman carrying a ruminant’s stomach brimming with milk found that by journey’s end, he had a bag full of curds and whey.

Modern cheese making is a little more complicated, but the same principles apply. Fresh milk is allowed to ferment, with either wild or cultured bacteria. Then, when they have raised the acidity enough, rennet—enzymes from calves’ stomachs (these have now been replaced with laboratory‑produced enzymes)—is added. This coagulates the caseins, which make up about 80 percent of the total milk protein, so that they form a gel.

Then there’s a lot of manipulation—cutting, stirring, and heating—that removes fluid, or whey, leaving behind solid curds. The curds are put into molds, salted or brined, and pressed, which expels more whey and turns the cheese into a solid mass. Mold may be added, either at the beginning or later in the process. Then, depending on the variety, the cheeses are matured for anywhere from two weeks to two years, allowing enzymes, both those from microbes and those from the rennet, to turn fats and proteins into tasty new substances.

Excerpted from Combat-Ready Kitchen: How the U.S. Military Shapes the Way You Eat*, by Anastacia Marx de Salcedo.*

Cheese is one of the bedrocks on which the Western diet is founded—a long‑term storage method for excess milk, especially when cool storerooms and caves were available. But the food didn’t fare so well during summer or in hot climates. With heat, animal fat softens or even liquefies, oozing out and creating an oily and unappealing mess.

In the early twentieth century, dairymen on either side of the Atlantic—the Swiss duo Walter Gerber and Fritz Stettler in 1911 and James Kraft in 1916—hit on and patented a solution to the seasonal sweats: emulsifying salts. The chemical disperses water‑phobic caseins by exchanging sodium for calcium; this permits the now smaller particles to be diffused and suspended in liquid. Melting traditional cheeses and mixing them with the emulsifying salts resulted in a cheese‑like product that withstands high temperatures and protracted storage.

Even better, this new food could be made and sold very cheaply, because it could be produced, at least in part, from the rinds and irregular bits left over from cutting wheels of cheese into bricks. Melting the ingredients also pasteurized them, inactivating the live bacteria and enzymes and contributing to a longer shelf life.

The army placed its first order for processed cheese–which at the beginning, came in only one flavor: white—during World War I, buying twenty‑five million quarter‑pound tins from Kraft. This single act probably established Kraft’s century‑long (and still going strong) food industry hegemony. By the time World War II rolled around, the military was a raving cheeseaholic, consuming the dairy product by itself, on sandwiches, or as sauces for vegetables, potatoes, and pasta.

In 1944 alone, the Quartermaster Corps bought more than one hundred million pounds from Kraft’s parent company, National Dairy Products Corporation (which finally itself took the Kraft name in 1969), as well as five hundred thousand pounds of cheese spread (bacon bits optional) to accompany the K and some of the C rations. During the war, the company’s sales almost doubled. But it still wasn’t enough. The military was hungry for new ways to store, ship, and eat cheese.

A 1943 war bond ad unveiled the product to the public with a picture of a bare‑chested soldier feeding a second soldier a cheese cake on a pointy stick.

At the beginning of the war, the army had embarked on a dehydration‑ and‑compression spree—by removing heavy water and reducing its volume, more food could be packed into a single shipment, always an advantage when there are millions of mouths to feed. All foodstuffs except meat were run through the drying chambers and squashed into bricks—fruits and vegetables, flour, potatoes, eggs, and cheese.

As would become its historic pattern, the military funded or supported a variety of efforts, some of which were destined to die a quiet death and others that would garner glory, becoming wartime staples and the basis for future consumer products. Cheese dehydration research was conducted by the Quartermaster Corps’ Subsistence Research Laboratory, through the USDA laboratories, at various universities, including the University of California at Davis, and by industry, notably Kraft.

Unless a food has a strong and flexible internal structure—think cellulose, the long chains of sugar molecules that give plant cells their rigidity—it crumbles when it dries out, something food technologists call fines. One can imagine the first experiment in drying and pressing a proud block of Wisconsin cheddar: cheese dust. This ruled out eating reconstituted cheese out of hand in slices or chunks. But for cooking, the granular form would be an advantage.

The first real cheese powder was developed in 1943 by George Sanders, a USDA dairy scientist. (Even before the war began, USDA’s research facilities had been enlisted to work toward military goals, exhorted by Secretary of Agriculture Henry Wallace “to consider their possible contributions to national needs as the defense program approaches the stage of ‘maximum effort.” This relationship continues to this day; the USDA has collaborated with the Quartermaster Corps and later the Natick Center on topics as varied as chemical testing, fungi collection and classification, potatoes, dairy, and, from 1980 on, operation of the army’s radiation food sterilization program.)

Until then, it had been “considered impossible to dehydrate natural, fat‑containing cheese,” because the heat melted the fat, which then separated out. Sanders’s innovation was to divide the process into two steps. In the first, the cheese, shredded or grated, was dried at a low temperature; this hardened the surface proteins of the particles, forming a protective barrier around the lipids. Once sufficient water had been evaporated, the cheese was ground and dehydrated at a higher temperature. The final step was to form it into what the patent describes as cakes. A 1943 war bond ad unveiled the product to the public with a picture of a bare‑chested solider feeding a second soldier bundled up in a parka with a cheese cake on a pointy stick:

For jungle or ski troops—a new kind of cheese! . . . But they should taste the same—and taste good—wherever they’re eaten. That has meant many headaches for the Army Quartermaster Corps and the food processors who supply them. . . . For emergency use in arctic and tropics, National Dairy laboratories developed a dehydrated, compressed cheese that keeps well anywhere and takes less shipping weight and space.

In the summer of 1945, Little Boy and Fat Man were detonated in Japan, ending the war and leaving the Quartermaster Corps with warehouses full of food as well as an elaborate manufacturing and distribution system still churning out goods for millions of troops. This would take years to redirect or dismantle. Fearful of the effect of the sudden withdrawal of its huge wartime contracts, the government propped up the dairy business first by buying their excess product and then, in some cases, by selling it back to them at lower prices. (The Commodity Credit Corporation, created during the Great Depression and still in existence, would later distribute these surpluses to welfare recipients and the elderly—the storied “government cheese.”) A temporary federal agency, the Surplus Property Administration, sold off at bargain‑basement prices the food the Quartermaster Corps had amassed.

Who doesn’t love something they get for free or at a third of the original cost? But what could one do with football fields full of potato flakes, a cave stuffed with dried eggs (the army’s strange storage location for one hundred million pounds of the stuff), or a mountain of dehydrated cheese?

Well, there was one group always interested in lowering the cost of finicky fresh ingredients: the grocery manufacturers, businesses such as Swift, Quaker Oats, General Foods, General Mills, Libby’s, Borden, McCormick, Colgate‑Palmolive, Gerber, Scott Paper, Kellogg’s, Pillsbury, and Kraft. (The strength of the companies that produced the packaged goods that lined the nation’s nascent supermarkets, many with deep military ties, only grew over the next century, as did that of their trade group, the Grocery Manufacturers Association, today the food industry’s most powerful lobbying organization.)

Perhaps instead of real cheese, the food corporations could mix in the cheap powder to add flavor. Not only would they save outright on the cost of ingredients, they’d pay a lot less to ship and store it—after all, that was the army’s primary purpose in developing dehydrated cheese in the first place. These ration conversions inspired a flood of fledgling products, particularly in the new and growing categories of convenience and snack foods.

In 1948 the Frito Company (it merged with H. W. Lay & Company in 1961 to become Frito‑Lay, Inc.) debuted the country’s first cheesy snack food, made with the same Wisconsin cheddar the army used for its dehydrated products. Frito Company founder Charles Doolin had been a military supplier, even building a facility in San Diego, where there is a naval base, to service his contracts.

According to his daughter Kaleta Doolin, “During the war, tins of chips were sent overseas to be served in mess halls and sold in PXs. This venture helped put the company over the top as a nationwide business.” Afterward, new plants were opened in Dallas, Los Angeles, and Salt Lake City, where soon cornmeal and water were being extruded, puffed, fried in oil, and coated with finger‑licking, orange dehydrated cheese. Cheetos!

Excerpted from Combat-Ready Kitchen: How the U.S. Military Shapes the Way You Eat, in agreement with Current, an imprint of Penguin Publishing Group, a division of Penguin Random House LLC. Copyright © Anastacia Marx de Salcedo, 2015.