Raising a Glass to Chemistry

Source: By GREGORY COWLES, New York TIMES • Posted: Tuesday, July 22, 2014

One of the great things about “Breaking Bad” was that it emphasized just how much the magic of intoxication depends on science. Walter White may have been a meth dealer and a criminal mastermind, but he was, above all, a really good chemist.

Alcohol also relies on chemistry — and a whole lot of other science, as Adam Rogers, an editor at Wired, makes clear in his lively new survey of the subject, “Proof: The Science of Booze.” When you take a sip of Scotch on the rocks, you’re probably not thinking about the processes of fermentation, distillation and aging that went into producing it. After reading this book, you will be, assuming the chapter on hangovers doesn’t stop you from ordering a drink in the first place.

Mr. Rogers starts with the basics. Alcohol (the kind we drink, anyway) is a byproduct of fermentation, created when yeast spores consume sugar and convert it to ethanol and carbon dioxide. This happens on its own in nature — left to rot, some fruit inevitably turns to booze — which means humans have probably been getting drunk far longer than they’ve understood how alcohol is made.

CreditAlessandra Montalto/The New York Times

He recounts the gradual discovery of yeast’s role by 19th-century biologists, including Louis Pasteur, and the scorn they initially faced from their chemist counterparts: “Early microscopists,” he writes, “had a reputation for seeing things that weren’t really there.” The effort to understand fermentation, to harness and standardize it, led to new fields of science, including organic chemistry and molecular paleontology.

How important is yeast? In 1996, it became the first living organism to have its DNA sequenced. As one modern alehouse puts it in a dubious ad: “Yeast — not just for infections anymore.”

There are many strains of yeast and many sources of sugar, leading to many kinds of alcohol. “In early America, colonists fermented just about everything they could find,” Mr. Rogers writes: “pumpkins, maple, persimmons and especially apples.” Fermented barley, which is to say beer, didn’t replace hard cider as the drink of choice in America until the arrival of German and Dutch immigrants in the 1800s.

This leads Mr. Rogers to a discussion of malting — essentially, coaxing barley to convert its starch to sugar — which in turn leads to a discussion of whiskey and distillation. (Other cultures have used other tricks to turn starch into sugar, including gnawing on grain and spitting it out so the enzymes in saliva can break it down. Talk about small-batch brewing.)

He illustrates his lessons with a series of field trips to labs and industrial production facilities, barhopping from factory to factory. He introduces us to the man with “quite possibly the single greatest title in all of academia” — Charlie Bamforth, the Anheuser-Busch endowed professor of brewing science at the University of California, Davis, who teaches Mr. Rogers about foam and effervescence in beer. He discusses the potential of gas chromatography to detect alcoholic forgeries trying to be passed off off as premium brands. He visits a small distillery in New York that has played loud dance music overnight, in hopes the deep bass would agitate the molecules in the liquid and help develop a fuller flavor.

Just as drinkers vary in their responses to liquor, so readers will vary in their tolerance for Mr. Rogers’s pert, gee-whiz tone. He acknowledges the problem: “The word ‘actually,’ ” he writes, “is why people don’t have drinks with me anymore.” But his descriptions of the science behind familiar drinks exert a seductive pull. In the name of research, I drank a lot more than usual while reading this book, just to connect the text with the complex flavors Mr. Rogers was writing about.

To a surprising degree, those flavors come from aging. When you store wine or spirits in oak barrels, the wood leaches tannins and other chemicals into the mix, turning the barrel itself into an essential ingredient in the finished product — as if all of your cookware were carved out of garlic. What’s more, oak has its own terroir, with different regions and different climates producing different flavor profiles. American oak-aged whiskeys are more perfumed, the book says, while French oak tastes more of vanilla and butterscotch.

After walking us through the making of alcohol, Mr. Rogers turns to the science of its consumption. That means psychology, mostly, because it turns out our experience of alcohol has a lot to do with our expectations. French researchers, for instance, served subjects a white wine dyed red and then watched them describe it with all the adjectives they had just attributed to a real red wine. Similarly, a Seattle psychologist found that given the right social cues, subjects showed signs of intoxication — flushed faces, slurred words, relaxed inhibitions — even when they were drinking a nonalcoholic placebo.

Other researchers have found that people don’t actually like the taste of alcohol, which is why they try to doctor it with all kinds of other things. What they do like, sometimes too much, is the way it makes them feel. (Mr. Rogers cites evidence that people with a sweet tooth and people unaffected by hangovers are more likely to become alcoholics.)

For all that we have discovered in the last 150 years about the science of alcohol, there’s still much to learn: Why does it affect our brains the way it does? What causes hangovers? Scientists aren’t sure.

“Ethanol is one of the few legal drugs of abuse,” Mr. Rogers writes, “and the only one that nobody really understands at the functional level.”

You can drink to that.