There was no recipe to be followed, so it was up to McGovern and Gerhart to apply quantities to the ingredients. Striving for maximum authenticity, McGovern suggested that the brew contain 50 percent brown rice (the technology for grinding off the outer layers of bran did not exist 9,000 years ago). He e-mailed Gerhart a list of modern rice strains closely related to those of Neolithic China. "Some of these rice species haven't been grown in 5,000 years," Gerhart said. He chose the pregelatinized rice favored by brewers: precooked to burst its starch cells and less likely to leave a mass of goop in the bottom of the vat.

McGovern wasn't sure whether the original fruit was a grape or a hawthorn, so he suggested they add a little of both. Each presented its own challenges. Hawthorn is the English name for the family of plants of the genus Crataegus, of which there are

THE FERMENT BEGINS

Brewer Mike Gerhart loads bags of malt—a modern concession to federal law—into the mash tun (below) and periodically checks its progress (right).

several hundred worldwide. It produces a small tart fruit that the Chinese use in both confectionery and medicine. It is possible to track down wild hawthorn fruit in season in this country, but no one sells it. Gerhart settled for a dried, powdered version—50 pounds of it, ordered online from an Asian herb company.

Likewise grapes. The Eurasian species, Vitis vinifera vinifera, probably did not reach the Far East until 2,200 years ago. Forty or 50 grape species still grow wild in China today—17 in Henan Province alone—but acquiring them proved impossible. So McGovern settled for a canned concentrate of muscat grapes, considered to be the closest kin genetically to wild Eurasian grapes. To drive fermentation, he bought a five-gallon bucket of honey.

Then there was a factor with which no Neolithic brewer would have had to contend: the Bureau of Alcohol, Tobacco, and Firearms. A federally licensed brewery is authorized only to make beer, and that beer must contain at least 25 percent barley malt. Alas, barley did not appear in China until about 5,000 years ago. Gerhart chose the lightest malt he could find, to interfere with the taste as little as possible.

Gerhart began the morning's brew by dumping the grains into the mash tun, a 200-gallon stainless-steel vat with a strainer in the bottom. He let them stew at 152 degrees Fahrenheit for an hour, to allow the enzymes in the barley malt to convert all the available starches to fermentable sugars. The resulting wort was pumped into the kettle, to be boiled with the hawthorn. Gerhart dumped bag after bag of orange hawthorn powder into the pot, his bemused shrug suggesting that he had only a loose idea of what effect it would have on the finished product.

The wort was slow to heat up, so Calagione and Gerhart took turns leaning over the cauldron with shovels, trying to keep the solids from sticking to the bottom. "I've never seen so much muck in the bottom of a tank," Calagione said. At last the mixture came to a boil. Gerhart ran the hot liquid through a heat exchanger and into the fermentation tank, where it was sweetened with the addition of the honey and muscat extract. In late afternoon, Gerhart inoculated it with a liter of liquid sake yeast, chosen because of its affinity for rice.

Three weeks of fermentation and the concoction would be ready for tasting. "Château Jiahu," as they dubbed it, will make its debut at the Waldorf-Astoria, at a party for Calagione's new book, Brewing Up a Business. I couldn't help asking Calagione how he planned to label the beer, given how far the project—with its barley and muscat grapes—had wandered from its Stone Age roots. He didn't blink: "We'll call it 'The Closest Approximation of the Oldest Alcoholic Beverage Ever Discovered.' "

McGovern, Calagione, and Gerhart seemed satisfied with the day's brew. I was not. Archaeology draws its authority from the science that underlies it, but its true

STIRRED, NOT SHAKEN

Neolithic brewers may have lacked sediment filters (above) and brewing hoses (below left), but like Gerhart, they doubtless sampled their brew as it fermented.
power derives from its ability to spark the imagination, to transport scientist and nonscientist alike back in time to another place, another culture, another frame of human mind. To make that trip we must shed at least some of our modern baggage. Château Jiahu, it seemed to me, was still too burdened by the present. Later, in my motel room, I expressed disappointment in a phone call to my fiancée. She came up with the obvious solution: "Well, you'll just have to make it yourself."

Start bandying about a word like authentic and you're setting yourself up for trouble. You might think you're as Neolithic as the next guy, but there's always somebody out there even more hard core than you, more willing to reenact the history of ceramics or the quest for fire to prove his point.

Still, how tough could this be? If I simply took the basic ingredients (or their modern descendants, anyway), threw them into a jar, and let them rot for a while, wouldn't that be authentic enough? I ran my theory past McGovern, who left me with a sobering thought: "One goal of the Neolithic beverage maker would be to make a drinkable beverage."

Two technological hurdles stood between me and quality. One was starch conversion; starches are long chains of sugars and can't be consumed by humans until first broken down. The second challenge was attracting enough wild yeast to ferment those sugars quickly, before marauding hordes of bacteria and fungi turned the brew into a frightful and possibly hazardous libation.

These riddles festered until the day I stumbled across the book Wild Fermentation by Sandor Ellix Katz, a fermentation fetishist. It was full of formulas for making pickled nasturtium capers, fruit kimchi, and other unusual dishes, as well as alcoholic drinks like chicha, the chewed-corn brew of the Andes, and chang, a mild, homemade rice beer still brewed in Nepal.

Katz laid out my starch conversion options: molding, malting, and chewing. Asia has a long tradition of inoculating cooked rice with the fungal culture of Aspergillus oryzae, a wild yeast that generates the enzyme amylase as it digests the grain. But the protective layer of bran on brown rice evolved to thwart this kind of parasitism, and my attempts to catch wild aspergillus ended badly.

Another option was to employ the rice grain's own enzymes, initiating them with the right combination of heat and moisture. That's how malting works. Compared with barley, however, brown rice generates too little amylase, and white rice won't sprout, which may explain why there is no strong tradition of malted beverages in the East.

I was down to my last option: chewing the grain and spitting it out. Horrifying, perhaps, to our fussy 21st-century sensibilities, this Neolithic technology is still very much alive today. In Africa they do it with manioc roots; in the South Pacific they do it with kava. The idea is simple: Digestion begins in the mouth. Saliva contains, among other things, ptyalin, a form of amylase. By chewing the grain, I myself would initiate the starch conversion.