Like beer? The proof is in the taste

WOULD YOU enjoy drinking beer as much if it didn't give you a buzz? Those bitter hops, that toasty malt - do we really need the alcohol to enjoy the flavor of a glass of ale?

It turns out, yes, we do.

In his new, utterly fascinating book, Tasty: The Art and Science of What We Eat (Scribner), Pulitzer Prize-winning author John McQuaid writes that ethanol - itself essentially flavorless - changes and improves the very chemistry of flavor.

First, the process of fermentation produces a host of byproducts that, although not themselves alcoholic, have flavors that are both "complex and provocative." These molecules may taste sugary or fruity or hot as a chili pepper.

Meanwhile, because alcohol alters brain chemistry, our perception of these flavors is fundamentally changed.

"You can drink pure alcohol and it will get you drunk," McQuaid told me in an interview. "But there's less pleasure or enjoyment involved. So, the flavor [of beer] is kind of a gateway to a broader experience."

McQuaid acknowledges that a lot about the mechanics and science of taste - the least understood of our senses - is still a mystery. Which is exactly why his book comes off as more of a provocative, entertaining inquiry than a final treatise.

Some of it is guesswork. For example, he acknowledges that we'll probably never know man's first alcoholic drink.

Nonetheless, he declares that the discovery of fermentation - basically, a natural breakdown of carbohydrates - rivals the very taming of fire. Once he learned how to ferment food, man could nourish himself with more than just animal meat and gruel. Suddenly, we could dine on a host of new foods: beer, wine, cheese, yogurt and even pickles.

"Just as the advent of cooking unleashed new flavors and nutrients that influenced the course of evolution, fermentation impressed itself on human biology," he writes.

This "torrent of new flavor molecules . . . 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."

Indeed, think of blue cheese or single malt whiskey or Belgian lambic. These are challenging flavors and aromas that almost seem designed to repel, like the odor of a skunk. From a pure survival of the fittest point of view, you'd think that humans wouldn't touch them with a 10-foot pole.

McQuaid told me: "We like things we shouldn't like - pungent or sour or strong flavors that are in contrast with each other. A lot of the stuff we eat seems objectively adverse. Our brain should be telling you to get the hell away from this. Yet, we embrace it.

"Nobody really understands why this is."

He theorizes that it's because mankind, in populating Earth, has lived in a lot of habitats, so we've learned to like a lot of different flavors.

But it doesn't explain why, in recent years, we've seen a trend toward pungency in our cuisine. Super hot peppers, Starbucks espresso, Greek yogurt, ultra-bitter double India pale ales - why are they all suddenly so popular?

"In the course of human history," McQuaid said, "the best we can say is that this sort of thing waxes and wanes."

Cultural and religious constraints notwithstanding, McQuaid says that we're evolutionarily designed to seek a balance between flavor and intoxication. As evidence, he points to the work of biologist Robert Dudley, who researched "monkey benders" in the Panama Canal. Dudley discovered that monkeys gobbling alcohol-laden palm fruit weren't out to simply "get hammered." Instead, they'd sample different pieces for the right balance of sweetness and alcohol, "as if at a wine tasting."

Dudley theorized that "a certain amount of alcohol in the diet is normal, and shaped human brains and metabolisms."

Yes, alcohol is ripe for abuse, and it turns out that too much of it can reduce our appreciation of flavor.

Recently, Spanish neuroscientists sought to measure alcohol's effects on taste by monitoring activity in the brain's "taste processing" area while subjects drank either weak or strong wine.

As reported by Discover magazine online, those who drank strong wine showed "weaker activation" compared with the light wine drinkers.

The researchers' theory: People tend to pay more attention to flavor when alcohol is low, allowing them to discern more.

Which is an argument, I suppose, for session beer - but not temperance.

"Joe Sixpack" is written by Don Russell. For more on the beer scene, sign up for his weekly email update at joesixpack.net. Email: joesixpack@phillynews.com.