The Drunken Botanist: The Plants that Create the World's Great Drinks

by Amy Stewart

  Colonists who lacked the technical skills to build a copper still found another way to do it—they’d leave a barrel of cider outside in winter, let the water content freeze, and siphon off the unfrozen alcohol. The “freeze distillation” method was dangerous: with no way to extract the concentrated toxic compounds that can usually be removed during distillation, the alcohol contained enough poison to contaminate the liver or cause blindness. That might have given applejack an undeservedly bad reputation, but fortunately, better distillation methods prevailed.

  Apples also make a fine eau-de-vie. Rather than running fermented apple juice through a still, eau-de-vie is typically made by crushing whole apples into a mash, fermenting it, and distilling a high-proof, clear alcohol. According to Cornell pomologist Ian Merwin, using whole crushed apples yields much higher levels of the aromatics that give apple spirits their flavor. “A good eau-de-vie made with mash fermentation tastes much more like an apple than Calvados does,” he said. It also helps that it is usually distilled in a more sophisticated fractional column still, which allows for more precise retention of aromatics. Calvados, by French law, must be distilled in an older-style alembic pot still, which is a more traditional but less exacting method of distillation.

  Eaux-de-vie are not finished in barrels, which means that the flavor comes entirely from the fruit and not from the oak. “With Calvados,” Merwin said, “you’re really just taking apple-based ethanol, which is a solvent, and putting it into oak to extract the oak flavors from it—which are admittedly nice in their own right. But there’s not as much apple flavor left when it comes out of the barrel.”

  Don’t tell that to a Calvados enthusiast. A nicely aged Calvados possesses a certain golden, sunlit quality that can only come from apples. It is best enjoyed neat, before or after dinner, or even in the middle of a meal: in Normandy the phrase trou normand, or “Norman hole,” refers to the glass of Calvados served between courses to create a hole in the appetite and make room for the rest of the meal.

  APPLE SPIRITS

  Apple brandy: A generic term for a spirit distilled from fermented apple juice or mashed apples, bottled at a minimum of 40 percent ABV, usually aged in oak.

  Applejack: In the United States, another term for apple brandy. “Blended applejack” contains at least 20 percent applejack; the rest is neutral spirits.

  Apple liqueur: A sweeter, lower-alcohol apéritif (often about 20 percent ABV) can be made from apples in a number of ways. One method would be to add apple brandy to fermenting cider before the yeast have consumed all the sugar. The higher alcohol content kills the yeast, stopping fermentation and resulting in a sweet drink almost like a dessert wine with fresh apple flavor. Apple liqueurs may be aged in oak before bottling.

  Apple wine: While apple wine is a very old term for cider, today it refers to a type of cider to which additional sugars and yeasts have been added to push the alcohol content higher, usually to at least 7 percent ABV. Apple wines are typically not carbonated.

  Calvados: Apple brandy made in a specific region of northern France, using apples from designated orchards, containing at least 20 percent local varieties, at least 70 percent bitter or bittersweet varieties, and no more than 15 percent sharp varieties. The spirit is bottled at a minimum of 40 percent ABV.

  Calvados Domfrontais: Follows the other rules for Calvados, but this apple brandy must contain at least 30 percent pears. It is single distilled in a column still and aged in oak for at least three years.

  Calvados Pays d’Auge: This is specific to the Pays d’Auge region; it follows all other rules for Calvados and must be double-distilled in a traditional copper still and aged in oak for at least two years.

  Eau-de-vie: A clear spirit made from fermented fruits that is not aged in oak and is bottled at 40 percent ABV or higher. It is the fruit equivalent of “white whiskey.”

  Pommeau: A delightful French blend of unfermented cider and apple brandy bottled at about 16 to 18 percent ABV.

  THE VAVILOV AFFAIR

  Russian botanist Nikolai Vavilov risked everything to preserve the wild ancestors of the apple tree. In the early twentieth century, he traveled the world to identify the geographic origins of such important crops as apples, wheat, corn, and other grains, collecting seed from hundreds of thousands of plants to establish a seed bank and advance the science of genetics. His goal was to improve crop yields for Russian farmers, but Joseph Stalin considered him an enemy of the state. Stalin had some funny ideas about science: he believed that a person’s behavior could change their genetic makeup, so that habits learned in one lifetime could be passed on through their DNA. Scientists who disagreed went to jail for it.

  Vavilov was arrested for his beliefs in 1940. He spent his last days delivering lectures on genetics to the other prisoners, many of whom surely wished Stalin would have arrested some locksmiths or dynamite experts instead of botanists.

  This version of an Old-Fashioned is mixed with equal parts applejack and bourbon, combining apples, corn, and grains in Vavilov’s honor.

  1 sugar cube

  2 dashes Angostura bitters

  ¾ ounce applejack

  ¾ ounce bourbon

  2 slices sharp apple, such as Granny Smith or Fuji

  Place the sugar cube in the bottom of an Old-Fashioned glass. Splash the bitters and a few drops of water on the cube, and muddle. Add ice, the applejack, and the bourbon and stir well. Use a citrus squeezer to squeeze the juice of 1 apple slice on top. Add the second slice to the glass as garnish.

  YEAST

  --- (a love story) ---

  Saccharomycetales spp.

  The oldest domesticated living organism is not a horse or a chicken, nor is it corn or wheat. It is a wild single-celled, asexual creature capable of preserving food, making bread rise, and fermenting drinks. It is yeast.

  Yeast is everywhere. It floats through the air, it lives on and inside of us, and it coats the skin of fruit in hopes of extracting some sugar from it. There’s no need to go hunting for wild yeast—leave a bowl of flour and water on the kitchen counter, and yeast will find it. But a few particular species of yeast—especially those belonging to the Saccharomycetales genus—are so effective at fermentation that people learned to keep them alive, grow them in large quantity, and, eventually, to sell them to brewers and distillers. There are laboratories all over the world carefully tending their strains of yeast. Wineries, breweries, and distilleries are often reluctant to remodel, move, or replace equipment for fear of destroying the native yeast that have taken up residence and added their unique characteristics to their products. Tests on identical batches of apple cider show that the particular strain of yeast can radically influence the flavor, introducing unique fruit and floral notes to the finished brew.

  The science of fermentation is wonderfully simple. Yeast eat sugar. They leave behind two waste products, ethyl alcohol and carbon dioxide. If we were being honest, we would admit that what a liquor store sells is, chemically speaking, little more than the litter boxes of millions of domesticated yeast organisms, wrapped up in pretty bottles with fancy price tags.

  But as waste products go, those of yeast are endlessly useful. We’ll dispense with the carbon dioxide first. If the fermentation is taking place in a vat, the carbon dioxide simply escapes. Beer makers allow some to remain so that the beer will be foamy. They might add a little back in during the bottling phase as well. In the case of sparkling wines, another bit of yeast goes into the bottle for a secondary fermentation that creates bubbles and builds up pressure behind the cork. (Bakers have much in common with brewers: carbon dioxide is what forces bread dough to rise.)

  But what about the other waste product, ethyl alcohol? That is what we call pure alcohol, or ethanol. After some tinkering, it makes for a great drink—but not for the yeast. As they excrete this alcohol, yeast make their own grave. They can’t survive in high concentrations of their own waste product, so as the alcohol content rises above about 15 percent, the yeast die off. That
explains why, until distillation was invented, no human had ever enjoyed a stronger drink than beer or wine.

  So that’s how it ends for yeast. Either they run out of sugar and die of starvation, or they eat so much sugar that the alcohol they produce kills them. Either way, they die doing what they do best: making drinks for us.

  If ethanol were the only product excreted by yeast in a vat of fermenting sugars, the world’s brandy makers and vodka distillers would have an incredibly easy time of it. They would simply dilute, flavor, and bottle the ethanol. But yeast, being living organisms, are imperfect, and the crushed grapes or mashed apples they live in are themselves brilliantly imperfect and complicated. There is more than sugar in a vat of grapes: tannins, aromatic compounds, acids, and forms of sugar that yeast cannot digest (also called non-fermenting sugars) are bouncing around as well. With so much going on in a fermentation tank, mistakes are going to happen.

  Many of those “mistakes” take place as the enzymes inside yeast cells try to do their job, which is to regulate chemical reactions. Think of an enzyme as a lock in search of a key. As molecules jump around in the fermentation tank, they may try to “lock” with an enzyme but not quite fit. The result of these imperfect couplings are imperfect compounds—and these make fermented drinks complex, intricate, and sometimes dangerous.

  These accidental by-products are called congeners—like the word congenital, meaning that the compounds were present from the birth of the fermented drink. Some of them are quite toxic and have to be carefully removed during distillation.

  If those poisons are made during fermentation, why isn’t beer or wine a deadly drink? First, brewers can control the fermentation process through their choice of equipment, the particular strains of yeast they use, and the temperature at which they allow fermentation to take place. Storing the fermented drink, or aging it in oak casks as winemakers do, causes further chemical reactions that can break down some compounds.

  Some congeners inevitably remain, but they are present in such relatively small quantities that our livers are usually able to keep up. Anyone who has had too much wine has experienced a hangover caused, in part, by a buildup of these toxins that the body simply can’t eliminate fast enough.

  The challenge of distillation, then, is to extract ethyl alcohol from a fermented mash similar to beer or wine, resulting in a higher-alcohol spirit that does not also deliver a concentrated dose of congeners. Fortunately, each of these compounds has a different boiling point, so the secret is to heat the mixture and separate out the unwanted molecules as they boil away.

  Light a fire under a vat of beer or wine, and toxic fusel oils vaporize first. Distillers call this the “head” of the distillation. It smells like nail polish remover. At the Plymouth gin distillery, they recycle it as an industrial cleaner. Next, as the temperature continues to climb, comes the “heart,” the ethyl alcohol that is the goal of distillation. At the end of the run come the heavier molecules that contain additional toxins, but also some of the more flavorful compounds that make whiskey and brandy taste so good. This section, the “tail,” must be cut off as well, but distillers may leave a little in to flavor their spirit.

  Knowing where to cut the heads and tails is the mark of a good distiller. Homemade moonshine, bathtub gin, and other such amateurish attempts at distillation can be fatal because those dangerous compounds might not be extracted properly. Cheaper, mass-produced spirits may also produce worse hangovers if those toxins were not properly extracted or filtered out. Some liquors are double-or triple-distilled, meaning the heart is run back through the still to extract more heads or tails, and some, like vodka, are filtered through charcoal to remove the slightest impurity, leaving a clear and mostly odorless and tasteless spirit that is as close as possible to pure ethyl alcohol.

  BUGS in BOOZE: a six-legged yeast delivery system

  Bugs in the brew? It is an age-old problem. Fermentation takes place in open tanks by necessity; otherwise, the pressure from the carbon dioxide would build to dangerous levels. But when a vat of fruit juice or grain mash is left to brew in an old barn or warehouse, bugs will surely find their way in. This is not always such a bad thing: lambic brewers in Brussels realize that some of their best strains of yeast come from insects falling from the rafters. In fact, yeast produce esters in order to attract insects, hoping they will pick up the yeast and move it around. This makes bugs unwitting accomplices in the dance between sugar and yeast.

  HOW DID THEY GET THAT PEAR IN THE BOTTLE?

  PEAR

  Pyrus communis

  rosaceae (rose family)

  Pear cider, or perry, is delightful when you can get it. The pears best suited to cider (called perry pears) tend to be small, bitter, dry, and more tannic than dessert pears. Pear cider is less common in part because pear trees are susceptible to a bacterial infection called fire blight, which is difficult to control; the disease has wiped out many old orchards. Pear trees also grow slowly and bear fruit later in life, making them a long-term investment rather than a quick crop, which is why farmers say, “Plant pears for your heirs.”

  Another issue is that once pears are picked they must be fermented immediately; they can’t be stored like cider apples can. Pears also contain a nonfermentable sugar called sorbitol, which adds sweetness but has one drawback: for people with sensitive systems, it acts as a laxative. One popular English pear variety, Blakeney Red, is also called Lightning Pear for the way it shoots through the system. This quirk has earned cider pears yet another folk saying: “Perry goes down like velvet, round like thunder and out like lightning.”

  Having said that, real pear cider—as opposed to apple cider with pear flavoring added—is well worth seeking out. It is sweet but not cloyingly so, and it has none of the tartness and acidity that some apple ciders possess.

  Pear brandy and eau-de-vie de poire are made in much the same way that apple brandy is, by distilling fermented pear mash or juice. Poire Williams is a popular French brandy made from Williams pears, which are known in the United States as Bartlett. It takes about thirty pounds of pears to create one bottle—and if that isn’t labor-intensive enough, some pear brandies are sold with a pear inside the bottle. When the fruit is small, bottles are carefully slipped over them and hung from nearby branches for support, making the orchards especially difficult to tend as the pears ripen, inside glass, on the trees.

  BARLEY

  Hordeum vulgare

  poaceae (grass family)

  Imagine a world without beer, whiskey, vodka or gin. Impossible! Yet it is no exaggeration to say that without barley, they wouldn’t exist. Among grains, barley is uniquely well suited to fermentation, so much so that it can even help with the fermentation of other grains—making it possible to coax alcohol from the most unlikely of sources.

  To understand the near-miraculous powers of barley, consider first the fact that cereal crops—barley, rye, wheat, rice, and so on—are not bursting with fermentable sugars the way apples or grapes are. Grains are packed with starch, which is a kind of storage system that allows plants to save the sugar they make during photosynthesis for some later use. To make alcohol from grains, the starch has to first be converted back to sugar.

  Fortunately, it takes nothing but water to persuade a plant to perform this trick. Each individual grain is, after all, a seed. When that seed germinates, it’s going to need some food to sustain it until it’s big enough to put down roots, spread out leaves, and make its own dinner. That’s what the stored sugar is for. All a brewer needs to do is to get the grain wet—a process called malting—which starts germination and prompts enzymes inside the grain to break down starch into sugar to feed the tiny seedling. Then it’s simply a matter of adding yeast to devour the sugar and excrete alcohol. Simple, right? Not exactly.

  Distillers learned the hard way that not every grain gives up its sugars so easily. That’s where barley comes in: it possesses unusually high levels of the enzymes that convert starch to sugar. It can be mixed with an
other grain, like wheat or rice, to jump-start the process in those grains as well. For that reason, malted barley is the brewer’s best friend—and has been for at least ten thousand years.

  the botany of beer

  Barley is a type of tall, very tough grass that isn’t bothered by cold, drought, or poor soil, making it widely adaptable around the world. In the wild, the spikelets of grains shatter and drop as soon as they are ready to germinate, but some enterprising early humans noticed that occasionally a barley plant would hold tightly to its grains. This was an ordinary genetic mutation that might not have had much benefit for the plant, but it was one that people liked: if the grains stayed on the stalk, they were easier to harvest.

  And that is how the domestication of barley happened. People selected seeds that possessed a trait they liked, and those seeds went around the world. Barley originated in the Middle East, making its way to Spain by about 5000 BC and to China by 3000 BC. It became a staple grain in Europe. Columbus brought it to America on his second voyage, but it wasn’t established in the New World until the late 1500s and early 1600s, when Spanish explorers took it to Latin America and English and Dutch settlers brought it with them to North America.

  It is easy to imagine the ancient, happy accident that led to the invention of beer. Picture a bucket of barley left to soak overnight to soften the tough outer husk. Wild yeast would have found its way into the bucket, and someone would have thought to taste the strange, foamy mixture that resulted from the yeast going to work on all those sugars. There it was: beer! Yeasty, bubbly, mildly intoxicating beer. The priorities of people in the waning years of the Stone Age must have undergone a rapid reshuffling as society organized itself around the need to reproduce this glorious mishap on a larger scale. (Is it any wonder that the Bronze Age, with its large metal tanks, came next?)