Cooked - A Natural History of Transformat Part 22

The alcohol itself probably contributed to the health, as well as the happiness, of ancient people. Alcohol is a rich source of calories as well as nutrients. People who drink in moderation (which a 5-percent mead pretty much guarantees) live longer and endure lower rates of many diseases than both people who don't drink at all and people who drink to excess. The exact mechanisms for these effects have yet to be identified, but the scientific consensus today is that drinking alcohol (of any kind) in moderation protects against heart attack, stroke, type 2 diabetes, arthritis, dementia, and several types of cancer. The teetotaler is at greater risk for disease and early death than the drinker.

Alcohol is a powerful and versatile drug, and for most of human history was the most important drug in the pharmacopeia-a panacea, literally. It reduces stress. It also m.u.f.fles pain, and for most of history served as humankind's princ.i.p.al a.n.a.lgesic and anesthetic. (Opium probably wasn't cultivated until 3400 B.C.) Also, many of the plant drugs, like opium, require alcohol as a solvent to unlock their powerful chemistries and make them available to us. In fact, it was once common practice to add various psychoactive plants (including opium and wormwood) to beer and wine; the addition of hops flowers to beer is all that remains of that venerable tradition.*

We humans owe a large debt to S. cerevisiae. Were it a creature that people could see, they might well decide this yeast has a stronger claim to the t.i.tle of man's best friend than the dog. Some evolutionary biologists contend that it was the world's very first domesticated species. Using DNA a.n.a.lysis, they've constructed an evolutionary tree for S. cerevisiae demonstrating that, more than ten thousand years ago, it diverged from a few, and possibly just one, wild ancestor into several distinct strains under the pressure of human selection. When humans began making mead and wine, brewing beer and sake, and baking bread, the yeast evolved and diversified to take maximum advantage of the rich new opportunities, or niches, humans presented it-whether a mash of grain, or diluted honey, or pressed grapes. Several thousand years later, the various strains of S. cerevisiae exhibit substantially different qualities, levels of alcohol production (and tolerance), and flavors. The process of "artificial selection" that shaped these yeasts is much like the one that transformed the wild wolf into a variety of different dogs, except that in the case of S. cerevisiae, the selection came earlier and was entirely unconscious.

In some cases, S. cerevisiae appears to have hybridized with other yeast species to acquire the genes it needed to make the most of a human fermentation opportunity. Consider lager, the cla.s.s of light, effervescent beers made by fermenting a mash of grain under cold conditions. Most strains of S. cerevisiae go dormant at temperatures below 55F. But when people in Bavaria began trying to ferment beers in caves during the winter, a novel strain of yeast that could thrive under those conditions soon appeared. (We now know it as Saccharomyces pastoria.n.u.s.) New tools of genetic a.n.a.lysis indicate that this hearty lager strain contains genes from a distantly related species of Saccharomyces, called Saccharomyces eubaya.n.u.s, that has been traced to Patagonia, where it is found on the bark of certain trees.* Researchers hypothesize that, shortly after Columbus's voyages, this cold-tolerant yeast found its way to Europe, perhaps in a shipment of lumber, or in a barrel that was then used to brew beer. So it appears that lager, like the tomato and the potato and the chili pepper, is yet another gift from the New World to the Old, tendered as part of the Columbian Exchange.

S. cerevisiae has demonstrated remarkable ingenuity in exploiting the human desire for alcohol, particularly in finding ways to transport itself from one batch of the stuff to another. Some strains get themselves pa.s.sed on by colonizing the vessels in which alcohol is fermented, or the wooden tools used to stir the pot. "Brewing sticks" are prized possessions in parts of Africa, believed to inaugurate the miracle of fermentation when used to stir a mash-and so they do, much like Sister Noella's wooden paddle. Other yeasts, like the ones that give us ale, evolved the trick of floating to the top of a fermented liquid, where they are much more likely to hitch a ride to the next sugary feast. That's because brewers typically scoop yeasts from the top of one batch to start the next. The most successful yeasts were the ones that learned to clump together and then float to the surface by attaching themselves to the rising bubbles of carbon dioxide-a conveyance that they of course created.

But surely the greatest evolutionary trick of all came when S. cerevisiae first figured out-unconsciously, of course-that the very same molecule it had originally devised to poison its enemies was also capable of making it a coevolutionary partner as powerful, ingenious, and well traveled as h.o.m.o sapiens. The human desire for alcohol has been a tremendous boon to Saccharomyces cerevisiae. To supply it with endless rivers of liquid substrate to ferment, we have reconfigured vast swaths of the earth's surface, planting tens of millions of acres of grain and fruit, in the process creating a paradise of fermentable sugars to sustain this supremely enterprising family of fungi.

In the 1980s, an anthropologist at the University of Pennsylvania by the name of Solomon Katz put forth the arresting theory that it was the human desire for a steady supply of alcohol, not food, that drove the shift from hunting and gathering to agriculture and settlement. Beer, in other words, came before bread, and as soon as people got a taste of it, Katz reasoned, they would have wanted more than could be produced by gathering seeds or fruits or honey. The hypothesis is difficult to prove, but plausible. It would certainly help explain why early humans would ever have traded the comparatively easy lifestyle of the hunter-gatherer, who typically devotes far less time and effort to obtaining food than the farmer, for the toil and inferior diet of the early agriculturist. A reliable supply of food is much easier to secure in the wild than fermentable sugars, which tend to be rare and hard to find. There is only so much honey in the forest, and what there is, is well defended by bees. The only way to guarantee an adequate year-round supply of fermentable sugars would be to take up agriculture. a.n.a.lysis of yeast DNA indicates that the domesticated strains go back at least as far as the domestication of grain, and perhaps further.

One suggestive new piece of evidence for the beer-before-bread hypothesis comes from the a.n.a.lysis of the carbon isotopes in the skeletons of ancient people in South America. Though corn had been domesticated by 6000 B.C., bones from the period immediately following give no evidence of corn proteins in the diet. This suggests that people were consuming the corn they were growing not as solid food but as an alcoholic beverage, since alcohol made from corn would contain little protein, hence leave little trace of it in bone. So it appears likely that Native Americans were drinking corn before they began eating it.

Yet it isn't at all self-evident how one would go about turning a pile of corn, or any other grain, into alcohol. To learn how to make beer is to marvel at the ingenuity of the people who first figured it out. The process is much more complicated, and involves many more steps, than making mead, or for that matter wine. Charlie Bamforth, the Anheuser-Busch Endowed Professor of Brewing Science at the University of California, Davis, likes to begin his lectures with a little joke. "Do you know why Jesus performed the miracle of turning water into wine? Because it's so much easier than making beer!"

Corn kernels, like the seeds of many other gra.s.ses, contain plenty of sugars, but they are not in a form that S. cerevisiae can make use of. The sugars are tightly bound together in long carbohydrate chains that the tiny yeasts can't break apart. This well serves the seed, which has an interest in keeping its precious cargo of sugars intact and safe from microbial attack until the germinating plant needs them. But certain enzymes can cleave those carbohydrate chains into simple, fermentable sugars, and, as the earliest beer makers discovered, one of those enzymes-ptyalin-is present in human saliva. The first beers were made by chewing kernels of corn and other seeds, mixing them with saliva, and then spitting the resulting slurry into a vessel, where it would readily begin to ferment. (The desire for an alcoholic drink must have been keen indeed.) To this day, there are indigenous groups in South America that rely on the chewing method to make an alcoholic beverage called chicha-a corn-and-saliva beer.

Surely there had to be a better way, and eventually it was discovered. Instead of chewing the grain to release its sugars, our ancestors figured out that if they briefly germinated the seeds before mashing them in water, the mash would become sweet enough to ferment. Malting, as this process is called, is essentially a way to trick the seed into releasing its own diastatic enzymes, to break down its carbohydrates into sugars to nourish the (supposed) new plant. In beer making, seeds of grain, most often barley (which contain high levels of both fermentable sugars and enzymes), are moistened and allowed to germinate for a few days before being dried in a kiln. The heat kills the embryonic barley plant, but not before the enzymes have been released and begun breaking down the seed's stash of carbohydrates.

In time, maltsters, as they were called, figured out that, by adjusting the cooking time and temperature in the kiln, they could take advantage of the browning reactions-Maillard and caramelization-to manipulate the flavor, aroma, and color of their beers. At the Oak Barrel, the long central aisle is lined with wooden bins with gla.s.s windows displaying more than a dozen different malts-cooked seeds of barley in colors ranging from pale gold to ebony, and giving off aromas as various and wonderful as raisin, coffee, chocolate, fresh bread, dark toast, biscuit, toffee, smoked peat, and caramel. It's a remarkably rich palette of flavors and aromas-sense metaphors, really-to tease out of a simple, and all but tasteless, seed of gra.s.s simply by cooking it.

But as I was about to discover, the choice of malt is only one of the daunting number of variables in brewing beer; there is also the type of hops that, depending on the strain, can impart completely different flavors (spicy, fruity, herbal, gra.s.sy, earthy, floral, citrus, or evergreen). Then there is the yeast, which helps determine exactly how sweet, bitter, fruity, or spicy your beer will be. Finally, there is the fermentation temperature and time, which can yield a crisp, light, bubbly lager at 45F (in forty-five days) or a softer, richer ale at room temperature (in fourteen days). The first time I set foot in the Oak Barrel, I was so daunted by the sheer number of decisions that went into brewing a beer-a beer!-that I turned around and left without buying a thing.

The second time, I bought one of the Oak Barrel's beer-brewing kits and, with the help of Isaac, brewed my first batch of beer. We opted for an English Pale Ale. The kit makes all the hard decisions, in effect, and contains everything you need: the malt (an English type called Crystal in our case), the hops (Magnum, Sterling, and Cascade), some flavoring grains (malted Carawheat), and a bag of priming sugars we would need when it came time to bottle. But when you buy a kit, the malted grain comes in the form of a liquid extract (made by grinding the malted barley, soaking it in hot water, and then evaporating the resulting "wort" down to a sweet, black syrup), and the hops come in little pale-green pellets. As Kel packed up our purchases, I wondered, were we somehow cheating by using a kit?

Brewing beer, even from a kit, turned out to be an enjoyable way for Isaac and me to spend a Sat.u.r.day afternoon together. Being an eighteen-year-old, Isaac had an acute interest in beer, and he approached the making of it in a spirit of high seriousness. It probably didn't hurt that fermenting alcohol was a grown-up enterprise that I knew no more about than he did, and which carried a faint whiff of outlawry. His mother wasn't entirely sure about the advisability of this particular father-son project, which also counted in its favor. The work itself called for four hands and at least one strong back (for lifting and pouring five-gallon kettles and heavy gla.s.s carboys), all of which combined to make for an agreeable collaboration of equals. Working side by side is always a good recipe for easy conversation with a teenager, and I learned more than I probably wanted to about various other beer exploits, involving consumption rather than production.

Following the Oak Barrel recipe, we began by boiling tap water in a five-gallon pot, poured in the malt extract, and then added the Magnum hops, a type used to bitter the beer. With a rolling pin, Isaac cracked the grains, which came in a muslin bag, and then suspended the bag in the rapidly boiling wort like a big tea bag. At the thirty-minute mark, we added the Sterling hops. After an hour, we took the kettle off the heat and added yet a third type of hops, Cascade, which is meant to contribute aroma. We cooled the liquid to room temperature, poured it through a strainer into a five-gallon gla.s.s carboy, and then "pitched" the yeast into it. The whole operation, which took slightly more than two hours from start to finish, felt a little like working from a cake mix, frankly. It might produce a decent cake, but would you be justified in calling the final product, however tasty, "homemade"?

And yet the following morning, when Isaac and I went down to the bas.e.m.e.nt to check on our carboy, we got pretty excited. Overnight, the big jug of honey-colored liquid had leapt dramatically to life. A thick layer of creamy foam had formed on the surface, like a great frothy head on a beer, and through the gla.s.s walls of the carboy we could see thick currents of brown wort circulating like powerful weather systems in time lapse. The little reservoir of water in the airlock was bubbling like crazy, releasing a damp, yeasty gas that smelled, agreeably, like an English pub. By now I knew all about yeasts and their appet.i.te for sugars, but it was hard not to feel there was some serious magic under way down here in our bas.e.m.e.nt.

After a few days, the fermentation settled into a less hectic rhythm, the bubbles now infrequent enough to count as they formed and, one by one, slid through the airlock to perfume the room. The currents in the wort slowed, too, and a whitish-gray ma.s.s of yeast and other detritus, called "trub," formed at the bottom of the carboy. (Only centuries of British devotion to beer making could produce such a superbly earthy vocabulary of Anglo-Saxon brewing terms: "trub," "wort," "pitch," "malt," "mash tun," and, my favorite, "sparge.") The instructions said we could bottle after two weeks, so, on a Sat.u.r.day morning, Isaac and I together hoisted the carboy out onto the back porch, and carefully siphoned the fermented liquid into bottles, which we then sealed with metal caps. We had already added the bag of priming sugar to the beer to stimulate a last climactic bout of fermentation in the bottles; trapped under the bottle cap, the carbon dioxide produced by the yeasts would disperse in the beer as bubbles. Two weeks later, it would be ready to drink.

Our English ale was pretty good, too. I mean, it tasted just like beer, which, at this point in my education, was good enough for me. Isaac was somewhat more discriminating. "The bubbles could definitely be livelier," he declared, "and I could do with less hoppiness." Befitting the English style, our ale was fairly bitter, with a p.r.o.nounced hops flavor and aroma. We had brewed two whole cases of the stuff, and I wondered if we would ever get through it all. But as the weeks went by, the beer got better and better, as the hops mellowed and the warm, malty flavors came to the fore. After a month of "conditioning" in the bottle, I felt good enough about Pollan's Pale Ale to bring a cold bottle down to Kel Alcala, at the Oak Barrel, for his professional evaluation. Kel, who is an earnest young brewer with a long blond ponytail and thick forearms tattooed with Goth-pagan imagery, poured himself a gla.s.s. He sniffed; he held it up to the light; he sipped. And then he stared at the beer for what seemed a very long time.

"For a first effort?" Kel's voice is a friendly growl. "I'd say this is really not bad at all." He brought the gla.s.s of beer to his nose a second time, inhaling deeply. "But I'm getting a slight off note in the finish. Do you get that? Fresh Band-Aid. Yep, that's it." I took a sip and had to admit he was right. There was a faint chemical scent reminiscent of first aid. "That comes from a compound called chlorophenol. I'm guessing your fermentation was a little warmer than you probably want. Even just a few degrees can do it."

It's funny how a well-chosen metaphor can, for better or worse, completely change the flavor of something. Never again could I drink Pollan's Pale without thinking about Band-Aids. Johnson & Johnson's Pale Ale would probably have been a better name for our first brew. But I was not discouraged. I wrote off the flaw to the fact that we had made this first batch in August; a second batch brewed over the winter turned out much better, with not even the slightest hint of hospital. Yet the Betty Crocker question still nagged at me, and when an opportunity presented itself to help brew a batch of beer truly from scratch, I grabbed it.

I had heard that a friend I hadn't seen in a few years, a psychiatrist whose son had gone to middle school with Isaac, had fallen deep into home brewing. I knew Shane MacKay to be an inveterate, if not obsessive, tinkerer and gear head (a serious guitarist, he also built his own amps and speakers from junkyard parts), and when I heard he had transformed part of his backyard into a brewery, I immediately gave him a call to see if I might a.s.sist on his next batch. I was certain Shane MacKay would not be using any kit.

There was the unmistakable hint of the mad scientist about Shane as he proudly showed me around his backyard setup early on a Sunday morning, his white thatch uncombed, his steel-blue eyes lit up by this latest DIY fire. Shane's teenage boys having long since lost interest in Dad's brewing project, the alchemist seemed delighted to have an eager new apprentice. In the shade of a lean-to he'd built behind the house, Shane had erected a tall structure of steel shelving to hold, at different heights, various kettles and kegs, each atop a propane burner, and all of them linked together by clear plastic tubing that pa.s.sed through various valves and spigots. Thermometers, hygrometers, jars of sanitizing chemicals, pumps, filters, funnels, carboys, bottles, airlocks, and propane tanks completed the scene. It occurred to me that, by learning to brew beer, Shane had found the perfect way to combine his engineering gifts with his professional interest in brain chemistry and how it might profitably be altered.

With the help of some incomprehensibly elaborate brewing software, Shane had concocted a recipe for a beer modeled on a traditional Irish ale; he was calling it, for obscure reasons, "Humboldt Spingo." As he typed into his laptop various parameters-types of malt, hops, and yeasts; temperatures and times-the software showed him exactly where the finished beer would fall along several different spectrums, including maltiness, sweetness, bitterness (measured in IBUs, or International Bittering Units), original and final "gravity" (dissolved solids), and alcohol level. Shane's whole approach-the software, the metrics, the scrupulous sanitation-was a world away from Sandor Katz's. Wild fermentation was the last thing Shane wanted going on in his carboys.

Shane had picked up the ingredients at the Oak Barrel the day before: a blend of malts, dominated by an English type called Maris Otter and supplemented with smaller amounts of Victory, Biscuit, Cara Red (for color), and a few ounces of roasted (i.e., unmalted) barley. For hops (which Shane proudly showed me he had planted along his back fence), we would use U.S. Golding to supply the bitterness (but not very much-the Irish ale style is considerably less bitter than the English) and Willamette for aroma. As for yeast, we were going to divide the batch in half and pitch two different strains: an English yeast and a Scottish. Shane proposed that I take one of the carboys home to ferment in my bas.e.m.e.nt, and later we could compare the effects on the beer of the different yeasts. A controlled experiment, or close to one.

Brewing from scratch, or "all-grain" brewing, begins with the soaking of the malt in hot (but not boiling) water. Before we added the crushed grain to the water, I sampled a few of the seeds. They tasted surprisingly good, sweet and nutty, but full of cellulose, like a ridiculously high-fiber breakfast cereal. The hour-long soak allowed the enzymes in the barley to break down the grain's carbohydrates into fermentable sugars. As we stood around the mash tun-a steel kettle with a screen at the bottom-watching the hot cereal steep, Shane asked about my brewing experiences to date. Being both a psychiatrist and a Canadian, he did a magnificent job politely masking his disdain for my Duncan Hines approach to beer making; he had started out the same way.

But though it added a couple of hours to the brewing process, steeping the grain seemed well within my capabilities. So did the next step, which was to sparge the cooked mash. After Shane opened a valve at the bottom of the mash tun to drain the sweet brown steep water into a second kettle, he directed a stream of boiling water from a third kettle overhead down onto the mash, in order to leach, or sparge, any remaining sugars from the nearly spent grains. After this water pa.s.sed through the mash, it emerged from the spigot below golden brown, warm, and fragrant. I tasted the grains again. They had been completely bleached of flavor.

Now we had our wort-thirteen gallons of sugary brown liquid. Shane poured a few ounces of it into a gla.s.s test tube into which he floated what looked like a big fat thermometer. In fact it was a hygrometer, which measures the density, or "gravity," of the wort: the amount of dissolved sugars in the liquid, which gives the brewer a good idea of just how much alcohol the final beer will contain. The scale on the side of the hygrometer indicated the wort had an "original gravity" of 10.50-precisely what the software had predicted. (When it dropped to 10.14, the software said, the fermentation would be complete.) Shane p.r.o.nounced himself pleased. Now he rigged up a system to cool the wort as quickly as possible by submerging a spiral of copper tubing that he then connected to a cold-water line. You want to cool the wort as rapidly as possible to minimize the risk of bacterial contamination. (The addition of hops, which contains antimicrobial compounds, also helps prevent contamination.)

Between steps, brewing beer consists mainly of hanging around watching pots boil, so there's plenty of time for talk. (Drinking, too, though, this being a Sunday morning, we stuck mainly to coffee.) Shane and I covered many bases, catching up on family and work and other fermentation projects. He asked about this book. I told him the premise, how the four elements corresponded to the princ.i.p.al methods humans have devised for transforming the stuff of nature into things good to eat and drink.

"So where does beer fit into your scheme?" Earth, I explained, since fermentation draws on the same microbial processes of destruction and creation at work in the soil. But then it occurred to me that, in fact, all four elements were represented in the beer-making process. The barley is first cooked over a fire; the grain is then boiled in water; and the beer, after fermentation, is carbonated with air. Beer is the complete four-element food. Which, I realized, is exactly the sort of insight you would expect beer to sponsor.

When, after forty-five minutes, the temperature of the wort had fallen to our target of 70F, we divided the liquid between two carboys and pitched the yeast, the English in one and the Scottish in the other. To aerate the yeasts, we vigorously shook and rolled the carboys till the wort began to froth. Then we plugged them with airlocks. Nearly five hours after putting the grain in to soak, we were done. Shane helped me hoist the carboy out to my car.

On the drive home, one hand on the steering wheel and the other steadying the neck of my carboy, I thought about S. cerevisiae, the invisible single-celled creature that had been the recipient of the morning's sustained and scrupulous attentions. "Man's best friend": By now, I had heard several brewers use the same phrase to describe it. But after devoting five hours of our weekend to the building of an idyllic environment for this species-a carboy full of sweet brown wort-it seemed to me it would be just as accurate to call Shane and me and all the other fermenters "Saccharomyces' best friend."

"Coevolution" is a strong term, implying that both partners have been changed by their relationship. It's not hard to demonstrate how the human desire for alcohol (bread, too) helped to redirect the evolutionary path of this particular fungus, as our species selected yeasts for their ability to ferment various substrates and produce varying amounts of alcohol or carbon dioxide. But for our relationship to this yeast to qualify as coevolution, the changes must be reciprocal. So can we make a case that S. cerevisiae changed us, too?

I think we can. While we were altering the genome of S. cerevisiae, it was altering ours: Our ancestors evolved the metabolic pathways to detoxify ethyl alcohol in order to make use of its prodigious energy (and, conceivably, some of its other benefits). Even today, not all humans possess the required genes, and some ethnic groups, lacking the ability to produce the necessary enzymes in their liver, have more trouble metabolizing alcohol than others. For them, alcohol remains more toxin than intoxicant. Yet the proportion of the human population that carries the genes to metabolize alcohol has almost certainly increased in the time since our species has been seriously drinking, in much the same way that the number of humans who can digest lactose as adults increased in places, such as Northern Europe, where cow's milk was widely available. In both instances, those who carried the genes needed to take advantage of the new food source produced more offspring than those who didn't.

Yet the changes that alcohol wrought in our species have not been confined to the human genome or the human liver. S. cerevisiae exerted what may be an even more profound, if somewhat harder to pinpoint, effect on the plane of human culture. Precisely where genes leave off and culture begins (or vice versa) is never an easy line to draw, since eventually useful cultural practices and values influence reproductive success, and so leave their mark on our genes. And though we don't yet know everything we would need to in order to write a comprehensive natural history of such important human traits as sociality, or religiosity, or the poetic imagination, when we do, there seems little doubt that S. cerevisiae (along with a few of the other species that produce important human intoxicants) will play a starring role. This little yeast has helped to make us who we are.

Alcohol is probably the most social drug we humans have. It takes cooperation to produce it, and it is commonly consumed in the company of others. In ancient Sumerian depictions of beer drinking, groups of people are shown sipping from the same gourd through straws. (Early beers would have been covered with a thick layer of dead yeast, foam, and floating debris, so were commonly sipped through straws.) In most cultures, anthropologists tell us, drinking alcohol has been a social ritual, and, much like hunting large animals and cooking them over fires, the practice helped foster social cohesion.

True, drunkenness can also lead to aggression and antisocial behavior, which is why drinking in many cultures is carefully regulated. But as paradoxical as this might sound, the very fact that alcohol inspired the need for such rules is another way in which it has contributed to our socialization.

This paradox points to one of the challenges of generalizing about alcohol's effect on us and our species: Almost anything you can say about it is true, and so is its opposite. This same molecule can make people violent or docile; amorous or indifferent; loquacious or silent; euphoric or depressed; stimulated or sedated; eloquent or idiotic.* Perhaps because it affects so many different neural pathways, alcohol is remarkably plastic in its effects, person to person, group to group, even culture to culture. As Griffith Edwards, the English author of Alcohol: The World's Favorite Drug, puts it, "Cultures can differ profoundly in their modes of drunken comportment." (A delicious phrase!)

Edwards suggests that this plasticity could explain why alcohol is so widely accepted as a recreational drug: "Intoxication with this particular substance is remarkably susceptible to cultural prescriptions and proscriptions, all the way from Bolivia to Tahiti." When you compare alcohol with other drugs-think of LSD or crack cocaine-it becomes clear that societies are better able to channel and regulate the response of individuals to alcohol, making the drug more socially useful and less threatening than some others.

So a natural history of human sociality would have to take account of the influence of alcohol in all its complexity. As would, I believe, a natural history of religion. "Wherever we look in the ancient or modern world," archaeologist Patrick McGovern has written, "we see that the princ.i.p.al way to communicate with the G.o.ds or the ancestors involves an alcoholic beverage, whether it is the wine of the Eucharist, the beer presented to the Sumerian G.o.ddess Ninkasi, the mead of the Vikings, or the elixir of an Amazonian or African tribe." Alcohol has served religion as a proof of G.o.ds' existence, a means of access to sacred realms, and a mode of observance, whether solemn (as in the Eucharist) or ecstatic (as in the worship of Dionysus or, in Judaism, the celebration of Purim). The decidedly peculiar belief that, behind or above or within the physical world available to our senses, there exists a second world of spirits, surely must owe at least a partial debt to the experience of intoxication. Even today, when we raise and clink gla.s.ses in a toast, what are we really doing if not invoking a supernatural power? That's why a gla.s.s of water or milk just doesn't do the trick.

In The Varieties of Religious Experience, William James placed alcohol at the very center of the religious experience. "The sway of alcohol over mankind is unquestionably due to its power to stimulate the mystical faculties of human nature," he writes, which are "usually crushed to earth by the cold facts and dry criticisms of the sober hour. Sobriety diminishes, discriminates, and says no; drunkenness expands, unites, and says yes. It is in fact the great exciter of the Yes function in man."

James is being perhaps a bit too unambiguously sunny here about alcohol, playing down the drug's potential for destructiveness. The ancient Greeks worshipped the wine G.o.d Dionysus, but always in the full knowledge of alcohol's paradoxical nature, how the same drug could make angels of us or beasts, confer blessings or bring down a curse. Indeed, that paradox goes to the very heart of the cult of Dionysus.* Wine "enters the world as a miracle," the cla.s.sicist Walter Otto wrote in Dionysus, but the drunken worship of Dionysus devolves into a kind of madness that is itself paradoxical. For it holds within it at the same time (here he quotes Nietzsche) "the power to generate and the power to destroy."

Otto's own sentences eventually fall under the Dionysian spell: "All earthly powers are united in the G.o.d: the generating, nourishing, intoxicating rapture; the life giving inexhaustibility; and the tearing pain, the deathly pallor, the speechless night of having been." (You'll recall that the Dionysian rapture ends badly, with the drunken revelers finally turning on the G.o.d to tear him limb from limb and then feast on his flesh.) "He is the mad ecstasy which hovers over every conception and birth and whose wildness is always ready to move on to destruction and death."

Have another?

To drink the wine of Dionysus is to dissolve the clear sunlit distinctions of Apollonian sobriety, muddying the bright lines between destruction and creation, matter and spirit, life and death-in fact, smearing the very idea of distinction itself. Commanding "the powers of earth," Dionysus' gravitational force pulls us back down into the primal mud. And yet: It is precisely here in the mud that creation begins, breeding the beauty of flowers-forms!-out of the dead ground, new life from death's rot.

"Just like fermentation," I scribble madly in the margins of my Otto. The Greeks had no scientific understanding of the process-that would await Louis Pasteur and the discovery of the responsible microbes-but it seems to me they deeply understood fermentation just the same. They had crushed grapes and watched great urns of blackish must begin to seethe and breathe and come to life, under the influence of a transformational power they ascribed to Dionysus. And they had felt what that same force did to their minds and bodies when they drank its creation, the way the liquid seemed to ferment them: shifting the mind's attention from the physical to the spiritual, italicizing everyday experience, proposing fresh ways of seeing the most familiar things-new metaphors. The Dionysian magic of fermentation was at once a property of nature and of the human soul, and one could unlock the other.

"Nature overpowering mind" is how Nietzsche described Dionysian intoxication, but for him, as for the Greeks, intoxication is no mere trifle or indulgence. Rather, it is the wellspring of a certain kind of creativity. Which brings me to the third natural history in which S. cerevisiae will surely loom large: the natural history of poetry.

That alcohol can inspire metaphor is something the poets themselves have been trying to tell us for centuries. "No poems can please long or live that are written by water drinkers," as Horace wrote two thousand years ago. So why don't we take the poets at their word on this? Perhaps because, as the heirs of Descartes, we're troubled by the idea that a molecule manufactured by a single-celled yeast could have anything to do with something as exalted as human consciousness and art. Matter should stay put over here; spirit over there.

"For art to exist," Nietzsche wrote, "for any sort of aesthetic activity or perception to exist, a certain physiological precondition is indispensable: intoxication." One could argue that he's speaking metaphorically here, that intoxication is a mental state that doesn't necessarily depend on a molecule. Let's grant that there are other, non-chemical ways to achieve an altered state of consciousness.* But, then, why is it we always use that particular metaphor-intoxication-to describe it? Probably because it is the model for the state of altered consciousness, or one of them. (Dreams would be another.) And because the fastest, most direct route to altered consciousness is an intoxicant, the most widely available one for most of human history being the molecule manufactured by S. cerevisiae.

The poet, wrote Ralph Waldo Emerson, speaks "not with intellect alone, but with the intellect inebriated with nectar." Put another way, new perceptions and metaphors arise when the spirit of Dionysus breaks Apollo's tight grip on the rational mind. "As the traveller who has lost his way throws the reins on his horse's neck and trusts to the instincts of the animal to find his road, so must we do with the divine animal who carries us through this world." Reins are useful, even necessary-like poetic meter-but the poet doesn't get very far without the animal instinct. "If in any manner we can stimulate this instinct, new pa.s.sages are opened for us into nature. ... This is the reason why bards love wine, mead, narcotics, coffee, tea, opium, the fumes of sandalwood and tobacco, or whatever other procurers of animal exhilaration." To the poet endeavoring to trope the prose of everyday life, a molecule like ethyl alcohol offers a powerful tool.