Free beer. And thus I found my way to a lecture in late February at the New York Academy of Sciences by renowned beer maven Charlie Bamforth. A man for whom the word "avuncular" was coined, the British Bamforth has three decades of brewing expertise under his belt. Over his belt is what he insists is "a sausage belly, not a beer belly."

"Beer is the basis of modern static civilization," began Bamforth, Anheuser-Busch Endowed Professor of Brewing Science at the University of California, Davis. "Because before beer was discovered, people used to wander around and follow goats from place to place. And then they realized that this grain [barley] could be grown and sprouted and made into a bread and crumbled and converted into a liquid which gave a nice, warm, cozy feeling. So gone were the days that they followed goats around. They stayed put while the grain grew and while the beer was brewed. And they made villages out of their tents. And those villages became towns, and those towns became cities. And so here we are in New York, thanks to beer." Another syllogism ended his address: "He who drinks beer sleeps well. He who sleeps well cannot sin. He who does not sin goes to heaven. The logic is impeccable."

In between came numerous nuggets about what Bamforth insists is "the world's favorite beverage," some of which were at the expense of another popular adult drink. While discussing the simple chemical equation of fermentation, by which a molecule of sugar is converted to two molecules of ethanol and two of carbon dioxide (along with some energy), Bamforth noted that "if the sugars are from grapes, you produce a fine beverage called wine. If the sugars are from grain, it's a superior beverage called beer."

Bamforth decried beer's sometimes dicey image: "Beer is perceived as a bad-boy drink, and beer has been too often marketed in all sorts of strange ways--flatulent horses [an infamous ad during the 2005 Super Bowl, overshadowed by the even more infamous Janet Jackson "wardrobe malfunction"] and men behaving badly. And wine is perceived some?how as being superior and speaking to a higher quality of life. Really, it's unfair. Beer is more consistent; it's produced with more devotion and care; it's at least as healthy." Plus, human feet are conspicuously absent from beer making.

But fetid feet pale when an ale becomes stale: tinted bottles or talented chemists must be employed to keep beer from becoming "sunstruck." Light converts certain beer bitter acids to the dreaded 3-methyl-2-butene-1-thiol (MBT) compound, a close relative of the malodorous thiols produced by Mephitis mephitis, the striped skunk. In his book Beer: Tap into the Art and Science of Brewing (Oxford University Press, 2003), Bamforth notes that some people can smell MBT at levels as low as 0.4 part per trillion. "These poor people," he writes, "would have been able to detect a tenth of a gram of MBT distributed throughout the balloon of the airship Graf Zeppelin II." Eau, the humanity.

So, does the brewski master have a favorite beer? "It depends on where I am," Bamforth explains. "If I'm in an old pub with a ceiling about my height and there's a roaring log fire, cask ale from England is sublime. I wouldn't have an American-style lager. If I'm at a Sacramento River Cats AAA baseball game and it's 100 degrees outside, I could kill for a Bud. I'm not going to drink a Guinness. So it's horses for courses." As long as those horses aren't flatulent.

Answering the charge that beer is empty calories, Bamforth points out that beer is actually rich in B vitamins, except for thiamine. "A famous doctor came up to me," he remembers, "and said, 'Is it true that if we could just boost the levels of thiamine, beer would be a meal in itself?' I answered, 'Even I wouldn't say that. You need a few pretzels.'"