This is the story you’ll often hear about how humans discovered cheese: one hot day nine thousand years ago, a nomad was on his travels, and brought along some milk in an animal stomach—a sort of proto-thermos—to have something to drink at the end of the day. But when he arrived, he discovered that the rennet in the stomach lining had curdled the milk, creating the first cheese. But there’s a major problem with that story, as University of Vermont cheese scientist and historian Paul Kindstedt told Gastropod: The nomads living in the Fertile Crescent of the Middle East in 7000 B.C. would have been lactose-intolerant. A nomad on the road wouldn’t have wanted to drink milk; it would have left him in severe gastro-intestinal distress.

Kindstedt, author of the book Cheese and Culture, explained that about a thousand years before traces of cheese-making show up in the archaeological record, humans began growing crops. Those early fields of wheat and other grains attracted local wild sheep and goats, which provide milk for their young. Human babies are also perfectly adapted for milk. Early humans quickly made the connection and began dairying—but for the first thousand years, toddlers and babies were the only ones consuming the milk. Human adults were uniformly lactose-intolerant, says Kindstedt. What’s more, he told us that “we know from some exciting archaeo-genetic and genomic modeling that the capacity to tolerate lactose into adulthood didn’t develop until about 5500 BC”—which is at least a thousand years after the development of cheese.

The real dawn of cheese came about 8,500 years ago, with two simultaneous developments in human history. First, by then, over-intensive agricultural practices had depleted the soil, leading to the first human-created environmental disaster. As a result, Neolithic humans began herding goats and sheep more intensely, as those animals could survive on marginal lands unfit for crops. And secondly, humans invented pottery: the original practical milk-collection containers.

In the warm environment of the Fertile Crescent region, Kinstedt explained, any milk not used immediately and instead left to stand in those newly invented containers “would have very quickly, in a matter of hours, coagulated [due to the heat and the natural lactic acid bacteria in the milk]. And at some point, probably some adventurous adult tried some of the solid material and found that they could tolerate it a lot more of it than they could milk.” That’s because about 80 percent of the lactose drains off with the whey, leaving a digestible and, likely, rather delicious fresh cheese.

Cheese Changed the Course of Western Civilization

With the discovery of cheese, suddenly those early humans could add dairy to their diets. Cheese made an entirely new source of nutrients and calories available for adults, and, as a result, dairying took off in a major way. What this meant, says Kindstedt, is that “children and newborns would be exposed to milk frequently, which ultimately through random mutations selected for children who could tolerate lactose later into adulthood.”

In a very short time, at least in terms of human evolution—perhaps only a few thousand years—that mutation spread throughout the population of the Fertile Crescent. As those herders migrated to Europe and beyond, they carried this genetic mutation with them. According to Kindstedt, “It’s an absolutely stunning example of a genetic selection occurring in an unbelievably short period of time in human development. It’s really a wonder of the world, and it changed Western civilization forever.”

Tasting the First Cheeses Today

In lieu of an actual time machine, Gastropod has another trick for listeners who want to know what cheese tasted like 9,000 years ago: head to the local grocery store and pick up some ricotta or goat’s milk chevre. These cheeses are coagulated using heat and acid, rather than rennet, in much the same way as the very first cheeses. Based on the archaeological evidence of Neolithic pottery containers found in the Fertile Crescent, those early cheeses would have been made from goat’s or sheep’s milk, meaning that they likely would have been somewhat funkier than cow’s milk ricotta, and perhaps of a looser, wetter consistency, more like cottage cheese.

“It would have had a tart, clean flavor,” says Kindstedt, “and it would have been even softer than the cheese you buy at the cheese shop. It would have been a tart, clean, acidic, very moist cheese.”

So, the next time you’re eating a ricotta lasagne or cheesecake, just think: you’re tasting something very similar to the cheese that gave ancient humans a dietary edge, nearly 9,000 years ago.

Camembert Used to be Green

Those early cheese-making peoples spread to Europe, but it wasn’t until the Middle Ages that the wild diversity of cheeses we see today started to emerge. In the episode, we trace the emergence of Swiss cheese and French bloomy rind cheeses, like Brie. But here’s a curious fact that didn’t make it into the show: When Gastropod visited Tufts microbiologist Benjamin Wolfe in his cheese lab, he showed us a petri dish in which he was culturing the microbe used to make Camembert, Penicillium camemberti. And it was a gorgeous blue-green color.

Wolfe explained that according to Camembert: A National Myth, a history of the iconic French cheese written by Pierre Boisard, the original Camembert cheeses in Normandy would have been that same color, their rinds entirely colonized by Wolfe’s “green, minty, crazy” microbe. Indeed, in nineteenth-century newspapers, letters, and advertisements, Camembert cheeses are routinely described as green, green-blue, or greenish-grey. The pure white Camembert we know and love today did not become the norm until the 1920s and 30s. What happened, according to Wolfe, is that if you grow the wild microbe “in a very lush environment, like cheese is, it eventually starts to mutate. And along the way, these white mutants that look like the thing we think of as Camembert popped up.”

In his book, Boisard attributes the rapid rise of the white mutant to human selection, arguing that Louis Pasteur’s discoveries in germ theory at the start of the twentieth-century led to a prejudice against the original “moldy”-looking green Camembert rinds, and a preference for the more hygienic-seeming pure white ones. Camembert’s green origins have since been almost entirely forgotten, even by the most traditional cheese-makers.

Listen to the latest episode of Gastropod for much more on the secret history and science of cheese:

Penicillium camemberti growing in a petri dish in Ben Wolfe’s lab. Photograph by Nicola Twilley.