Tasty (9 page)

Ancient drinks are McGovern's specialty. The work is challenging because alcohol doesn't leave traces: it evaporates quickly, and stray molecules are likely to be consumed by microbes. Most of his evidence is circumstantial, based on other ingredients he can decipher. Chemically analyzing the remains of the drink, McGovern found tartaric acid, which comes from fruit. The signature of beeswax pointed to honey as another ingredient. Finally, a test for carbon isotopes showed that rice had been present. Traces of tree resins (often used by ancient vintners as a preservative, and conferring a lemony tang) and herbs also appeared. The beverage would have been a cross between mead and wine, made from fermented honey, grapes, hawthorn berries, and rice. It was probably used in religious ceremonies. But it was also ordinary: drink-infused pottery shards were found both in graves and in homes. This was Jiahu's equivalent of a six-pack.

McGovern wasn't satisfied with knowing which chemical ingredients were used to make the Jiahu grog. He wanted to taste it. A sip, he felt, could help summon to life previously lost and inaccessible moments. It could help explain how civilization had changed humanity, reaching beyond the usual musty clues into an ancient people's lived experience—not just
what
they tasted but
how
they tasted, and felt.

In 1999, McGovern had teamed with Sam Calagione, founder of the Dogfish Head Craft Brewery in Milton, Delaware, to re-create an ancient brew from ingredients found in the 2,700-year-old tomb of King Midas, in Turkey. Calagione was motivated by naysayers who had denounced his early craft beers and their unexpected ingredients, such as juniper berries, chicory, and licorice root. “A lot of so-called purists, I'd say elitists, would say, ‘You're screwing with the history of brewing!'” he said. Researching that history, Calagione found that modern beer recipes dated to a 1516 Bavarian law called the
Reinheitsgebot
, or “beer purity act,” which mandated that the only ingredients of beer be water, barley, and hops (plus yeast, which wasn't known in the sixteenth century). The law is still in force in Germany, though imported beers are exempt.

Calagione set out to recover some lost pre–purity act brewing traditions. When he met McGovern, he said, “I could tell we were kindred spirits.” Together, they tried to approximate ancient ingredients for the King Midas brew. To prepare a three-thousand-year-old Egyptian ale named Ta Henket, Calagione placed petri dishes laced with sugar at an Egyptian date farm to capture airborne yeasts, mapped their DNA to assure their provenance, and grew strains that were likely descendants of those used by the pharaohs. To make an ancient Peruvian corn ale, he spent four days chewing corn kernels so his spit would break down their starches into sugars.

For the Jiahu brew, McGovern and Calagione had only a list of likely ingredients from the original chemical analysis, with no quantities or instructions. The Jiahu people had gathered their ingredients from nearby forests and hillsides, as well as their own rice stores. Nine thousand years later, McGovern and Calagione would have to improvise. Chinese
grapes that would have been a good match weren't readily available in the United States. Nor were the small, tart hawthorn fruits. The pair settled on canned muscat grapes, which are genetically similar to the wild Eurasian grapes the Jiahu artisans used. They were able to import hawthorn berry powder from China in fifty-pound bags.

The Jiahu people had grown and processed rice. This meant that neither brown rice (unprocessed) nor white rice (processed with modern technology) would do for the re-­created brew. So McGovern and the Dogfish Head team used a kind of precooked rice with some bran and hulls still present. Finally, to set the stage for fermentation, the starches in the rice had to be broken down into sugars that yeasts could metabolize. For that, they turned to a concoction used in Asian cuisine known as
koji
, rice inoculated with a fungus,
Aspergillus oryzae
, that did the job. This was also a cheat, as villagers would have used more primitive means—spit, which contains the necessary enzymes. After a three-week brewing process, they had a beverage they called “Chateau Jiahu.” McGovern found it delicious: effervescent, rich, brooding. (He also concluded it was an ideal complement to Chinese food.) I tried it myself. The honey gave it a smoothness, before a bitter aftertaste kicked in. It was not hard to imagine a summer evening, the sun going down, the rice and pigs tended to, a small fire burning, and perhaps the sound of a flute.

• • •

Throughout history, hungry microbes have fermented not only ripening fruits and honey but many edibles, launching a stream of culinary experiments. One began a few thousand years before Jiahu was founded, about four thousand miles away in a mountain range that spans present-day Turkey and
Iran, when a scene something like this must have occurred: A herdsman arose from the shadow of a lean-to. The morning light revealed a small herd of goats flecking the hillside below. He walked to a nearby pen made with woven branches for the female aurochs—a now-extinct wild ox—and her calf that he had captured. Aurochs were ornery, but this one was the calmest animal he had ever seen, and so with some effort he had managed to tame and breed her. He tugged on the aurochs's udder, filling a clay jar with milk. Milk made him sick to his stomach. But when he set it aside for a day or two, the lumpy curds—the simplest form of cheese—made a satisfying meal.

Aurochs were huge bundles of muscle, an irresistible food source, and herdsmen by this point had long experience handling flocks of goats and sheep. But both of those were docile creatures. Wild goats even sheltered in mountain caves; they were used to being penned. Aurochs were wild, mean, and unpredictable. Capturing and breeding them was nearly impossible.

Scientists led by Ruth Bollongino of the French National Centre for Scientific Research in Paris analyzed the DNA of modern cows and compared it with ancient DNA from fossils. They concluded that all cattle alive today are descended from about eighty wild animals, and that the original domestication probably happened in a single place in the Eurasian mountains—perhaps two—in an ambitious, or maybe just stubborn, project spanning generations. By comparing the DNA evidence with archaeological evidence of cattle herding, the scientists estimated that success took almost two thousand years. Dairy cheeses, the predominant type of cheese in the world, emerged during this arduous process, which changed human genes, biology, and tastes.

Before cattle were domesticated, almost all human adults lacked the ability to digest lactose, a sugar plentiful in the milk of all mammals. Children's bodies produced lactase, an enzyme that breaks down lactose, but they lost that ability as they matured. This is common among mammals after weaning: it eliminates the temptation to return to mother's milk. For the lactose-intolerant, drinking milk causes unpleasant side effects such as gas and diarrhea. Prehistoric herders would have found it maddening to have a huge nutritional resource at their fingertips that only children could drink.

But as milk ages, rod-shaped microbes start to break down its lactose. The Lactobacillales are an order of bacteria entwined with both the human body and the food we eat.
Lactobacillus acidophilus
, which is used to make yogurt, is found in the mouth and throat, small intestine, and vagina. Several species of
Streptococcus
, members of the same order, cause strep throat and pneumonia; others are used in making cheese. Spoiled milk is essentially partially digested, its lactose already broken down. This discovery was a nutritional bounty for our ancestors: adults who couldn't drink milk could tolerate dollops of bacteria-processed curds.

Cattle produce milk in vastly greater quantities than goats or sheep. As domestication efforts finally started paying off about ten thousand years ago—some generations after the lonely aurochs breeder's experiment—herdsmen began to swap their sheep and goats for cattle. Herding swept west and north across Europe, and with it genes enabling people to digest lactose. A positive feedback loop was under way: people able to consume milk and cheese fared better in dairying societies; dairying expanded as more people consumed milk and cheese. Today, only about 5 percent of northern Europeans are lactose intolerant. In parts of West Africa and Asia,
where dairying never caught on, most people remain lactose intolerant.

A craft developed as dairyers made vessels to store milk and tools to handle it. Scientists have found the carbon signatures of milk fat on pottery shards from northwestern Anatolia, Turkey, dating from about 8,500 to 7,000 years ago, and clay strainers used to separate curds and whey in Kuyavia, Poland, about 1,500 miles away, dating from about the same period.

To temper their sour, lumpy cheeses, ancient herdsmen might have applied lemon juice or vinegar to hasten fermentation, or salt water, to brine the cheese. They could also have suspended a vessel of soured milk over a fire, letting heat condense the curds. Altering the balance of time, heat, and moisture in these processes made some cheeses sour, others mild and creamy, some dense and sharp. Some smelled like ripe sweat.

Prehistoric herders using animal stomachs as canteens likely found the milk they carried already congealed. The catalyst was rennet, a powerful, enzyme-rich coagulant found in the digestive systems of sheep and goats; it helps them digest milk by slowing its entry into the small intestine. Rennet attacks milk proteins called caseins, long, twisty molecules held together in loose, water-repellent globes. When broken, the globes begin to clump together. In cheeses, rennet creates a solid consistency. Cheese made with lactic acid bacteria alone tends to be mushy or crumbly, while rennet cheeses, including ubiquitous cheddar, Swiss, and gouda, are firm. It also provides a secondary dose of broken-down caseins for the
Lactobacillus
bacteria to metabolize and turn into flavor. Over the last two thousand years or so, still more microbes were added to the mix, most by accident at first. Molds grow on
cheeses naturally; people found some tasty, and found ways to use them. One of them,
Penicillium roqueforti
, used to make blue cheeses, generates lipases, enzymes that break down fats as the cheese ripens, producing pungent tastes and blue-green marbling.

Recruiting these new microorganisms was, in essence, an ancient form of bioengineering. Unlike baker's yeast, some weren't naturally suited to the job; they had to be tamed. “We select for sheep that have lots of wool, cows that have lots of muscles, and plants that have larger fruits. If you start thinking about food, wine, cheese, and yogurt all involve the use of microbes that have been domesticated by humans. But whereas we know a lot about plants and animals, we don't know as much about what we did with the microbes,” said biologist Antonis Rokas of Vanderbilt University.

Aspergillus oryzae
, the
koji
fungus employed in making Chateau Jiahu, produces fine yellow-green filaments called hyphae, invisible to the naked eye, but sometimes coated with spores that give it the appearance of fuzz. It breaks down starches to sugars, which baker's yeast then converts to alcohol. Variations of this one-two combination are present today in all beverages made from grains, including beer, sake, and whiskey.
Aspergillus
-infused rice is used on soybeans to make soy sauce, miso, and other dishes. Japanese supermarkets sell it in sealed plastic bags. Rokas and his lab team compared the
Aspergillus
oryzae
genome (sequenced by Japanese scientists in 2005) to that of its closest wild relative,
Aspergillus flavus
, as one might compare the genes, anatomy, and behavior of a cocker spaniel with those of a wolf to understand how dogs became dogs.

Aspergillus flavus
is a scourge of agriculture and the source of a potent poison called aflatoxin, which causes liver cancer,
acute hepatitis, and immune system damage. The two fungi share 99.5 percent of their genes; DNA evidence suggests
Aspergillus oryzae
probably originated from a single domestication of an
Aspergillus flavus
culture by some East Asian perhaps four thousand years ago.

Just as dogs were bred for friendliness and loyalty, the
koji
fungus was bred to make flavor. The first clue was its consistency. The
flavus
DNA varied a lot from batch to batch. Some of the
flavus
fungi were even nontoxic; that ancient brewing pioneer probably chose those (and made people ill if he chose others). But the
koji
fungi were genetically alike, all highly efficient at breaking down starches and producing flavorful by-products. One of their genes carried instructions for making glutaminase, an enzyme that helps produce the active ingredient in umami. A cluster of nine genes produced sesquiterpenes, compounds found in ginger, jasmine, and lemongrass that heighten aromatic sensations. Several of these molecules are manufactured and used by food companies today.

• • •

The torrent of new flavor molecules unleashed by fermentation galvanized ancient humans' senses of taste and smell. Flavor's great power derives from the synergies it creates between senses, different systems of the body and brain uniting to form something greater than the sum of their parts. Fermented foods, in particular, amplify this effect. “I am tempted to believe that smell and taste are in fact but a single sense, whose laboratory is in the mouth and whose chimney is the nose,” gourmand and former French revolutionary Jean Anthelme Brillat-Savarin wrote in his 1825 book,
The Physiology of Taste: Or, Meditations on Transcendental Gastronomy
. A journey through the worlds of cooking and the senses, the
book founded an enduring genre: the culinary essay. (Brillat-­Savarin also penned the aphorism “you are what you eat.”) In it, Brillat-Savarin suggested flavor was properly viewed not as a static phenomenon but as a process. As it unfolded, senses were activated—sometimes separately, sometimes together—before ultimately merging: