Agave tequilana AGAVACEAE (AGAVE FAMILY)
The agave is better known for what it is not than for what it is. Some people think it is a kind of cactus; in fact, it is a member of the botanical order Asparagales, making it more similar to asparagus and a few other unlikely relatives: the shade-loving garden ornamental hosta, the blue hyacinth bulb, and the spiky desert yucca.
Another misconception arises when agaves are called century plants, suggesting that they bloom once in a hundred years. In fact, many bloom after eight to ten years but "decade plant" doesn't sound nearly as romantic. The much-anticipated bloom is vitally important, however: it yields the raw ingredients for tequila, mezcal, and dozens of other drinks distilled or fermented from this strange, heat-loving succulent.
The first drink to be made from agave was pulque, a mildly fermented beverage derived from the sap, or aguamiel. We know from remnants found at archeological digs that agave—called maguey in Mexico—was cultivated, roasted, and eaten eight thousand years ago; the sweet sap surely would have been drunk as well. Murals dating to 200 AD at the pyramid in Cholula, Mexico, depict people drinking pulque. The Aztec Codex Fejérváry-Mayer, one of the few pre-Columbian books not destroyed by the Spanish, portray Mayahuel, goddess of the agave, breast-feeding her drunken rabbit children, presumably offering them pulque instead of milk. She had four hundred children in all—the "Centzon Totochtin"—and they are known as the rabbit gods of pulque and intoxication.
The strangest bit of evidence for pulque's ancient origins comes from a botanist named Eric Callen who, in the 1950s, pioneered coprolite analysis, or the study of human feces found at archeological sites. He was ridiculed by his colleagues for his bizarre specialty, but he did make some astonishing finds concerning the diet of ancient people. He claimed that he could confirm the presence of "maguey beer" in two-thousand-year-old feces just from the odor of the rehydrated samples in his laboratory—which is either a testament to his sensitive nose or to the powerful bouquet of very old pulque.
To make pulque, the flowering stalk of the agave is cut just as it starts to form. The plant waits its entire life for this moment, stockpiling sugars for a decade or more in anticipation of the emergence of this single appendage. Cutting it forces the base to swell without growing taller; at that point, the wound is covered and allowed to rest for several months while the sap builds. Then it is punctured again, causing the heart to rot. This rotten interior is scooped out and the inside of the cavity is repeatedly scraped, which irritates the plant so much that sap begins to flow profusely. Once it begins flowing, the sap is extracted every day by means of a rubber tube or, in the old days, a pipette made from a gourd called acocote. (The acocote, in case you are inclined to grow your own, is often made from the long, skinny segment of Lagenaria vulgaris, a common bottle gourd also used to make bowls and musical instruments.)
A single agave can produce a gallon a day for months at a stretch, yielding over 250 gallons in all, far more than the plant would contain at any given time. Eventually the sap runs dry and the agave crumples and dies. (Agaves are monocarpic, meaning that they bloom only once and then expire, so this is not as much of a tragedy as it may seem.)
The sap needs less than a day to ferment—historically, this took place in wooden barrels, pigskins, or goatskins—and then it is ready to drink. A bit of the previous batch, the "mother," is usually added to start the process. It ferments quickly thanks in part to the naturally occurring bacteria Zymomonas mobilis that live on the agave and on other tropical plants that are made into alcohol, such as sugarcane, palms, and cacao. (These bacteria do such an efficient job of producing ethanol that they are used to make biofuels today.) However, this microbe is entirely unwelcome in other brewing processes. It is the cause of "cider sickness," a secondary fermentation that can ruin a batch of hard cider. It can spoil beer as well, releasing a nasty, sulfuric smell in a tainted batch. Still, it is the perfect catalyst for turning agave sap to pulque. Saccharomyces cerevisiae, the common brewing yeast, helps with fermentation, as does the bacterium Leuconostoc mesenteroides, which grows on vegetables and also ferments pickles and sauerkraut.
These and other microorganisms bring about a quick, frothy fermentation. Pulque is low in alcohol—only 4–6 percent alcohol by volume (ABV)—and has a slightly sour flavor, like pears or bananas past their prime. It is something of an acquired taste. Spanish historian Francisco López de Gómara, writing in the sixteenth century, said: "There are no dead dogs, nor a bomb, that can clear a path as well as the smell of [pulque]." Gómara might have preferred pulque curado, which is pulque flavored with coconut, strawberry, tamarind, pistachio, or other fruits.
Because no preservatives are added, pulque is always served fresh. The yeasts and bacteria remain active and the taste changes within a few days. Canned, pasteurized versions are available, but the microbes die off and the flavor suffers. It is, after all, the lively microbial mix that wins pulque comparisons to yogurt as well as beer. With its healthy dose of B vitamins, iron, and ascorbic acid, pulque is practically considered a health food. While beer has been the beverage of choice in Mexico for decades, pulque is making a comeback not only in Mexico but in border cities like San Diego as well.
mezcal and tequila
Any number of popular books on tequila and mezcal claim that when the Spanish arrived in Mexico, they needed a stronger drink to fortify themselves against the long and bloody struggle to come and introduced distillation as a way to turn pulque into a higher-proof spirit. In fact, tequila and mezcal are made from entirely different species of agave than pulque. The method for harvesting the plant and making the spirit is completely different, too.
It turns out to be very difficult to put pulque in a still and get strong liquor from it. The complex sugar molecules in agave nectar don't break down readily during fermentation, and heat from distillation causes unpleasant chemical reactions that create nasty flavors like sulfur and burning rubber. Extracting agave sugars for distillation requires a different technique—one that had already been perfected before the Spanish arrived.
Archeological evidence—including the aforementioned coprolite analysis carried out by Eric Callen and others—proves that people living in Mexico prior to the Spanish invasion enjoyed a long tradition of roasting the heart of the agave for food. Pottery fragments, early tools, paintings, and actual remnants of digested agave all confirm this beyond a doubt. Roasted agave is a gourmet experience; imagine a richer, meatier version of grilled artichoke hearts. It would have made a fine meal by itself.
But a high-proof spirit can also be made from the roasted hearts. The roasting process breaks down the sugars in a different way, yielding lovely caramelized flavors that make for a rich, smoky liquor. When the Spaniards arrived, they observed the locals tending to agave fields, monitoring the plants closely, and harvesting them at a precise point in their development, right before the bud emerged from the base to form a flowering stalk. Instead of scraping out the center to force the flow of sap, as was the practice for making pulque, the agave leaves were hacked away, revealing a dense mass called a piña, which resembled a pineapple or an artichoke heart. Those were harvested and roasted in brick or stone-lined ovens set in the ground, then covered so that they could smolder for several days.
Native people had clearly worked out a method for cultivating and roasting the agave. Pre-Columbian stone pits built for this purpose can still be found in Mexico and the southwestern United States. Now some archeologists point to remnants of crude stills to suggest that people might not have simply roasted the agave for food—they might have already been working on distillation methods prior to European contact.
This is a controversial idea hotly debated among academics. What we know for certain is that the Spaniards introduced new technology. Many of the earliest stills in Mexico are a derivation of the Filipino still, a wonderfully simple bit of equipment made entirely from local materials—mostly plants themselves. The reason the Spaniards get credit for this is that they are the ones who brought the Filipinos to Mexico, courtesy of the Manila-Acapulco galleons. These trading ships took advantage of favorable breezes that made it possible to journey directly from the Philippines to Acapulco in just four months' time. For 250 years, from 1565 to 1815, the ships brought spices, silk, and other luxuries from Asia to the New World, and they carried back Mexican silver for use as currency. The crosspollination of cultures between Mexico and the Philippines survives even today, with the Filipino still being just one example of the connection between the two regions.
This simple still consisted of a hollowed-out tree trunk (often Enterolobium cyclocarpum, a tree in the pea family called guanacaste, or elephant ear) perched above an inground oven lined with bricks. The fermented mixture would be placed inside the tree trunk and brought to a boil. A shallow copper basin sat atop the tree trunk so that the liquid could boil and rise to the copper basin, much like steam collecting in the lid of a pot. This distilled liquid would then drip onto a wooden chute placed below the basin and run out of the still by way of a bamboo tube or a rolled agave leaf. More traditional copper Spanish stills, called Arabic stills, were also introduced early on.
Whenever distillation started in Latin America, the practice was well established by 1621, when a priest in Jalisco, Domingo Lázaro de Arregui, wrote that the roasted agave hearts yielded "a wine by distillation clearer than water and stronger than cane alcohol, and to their liking."
* * *
Over the last few centuries—and until the last decade or so—agavebased spirits were considered to be rough products that in no way compared to a good Scotch or Cognac. In 1897, a Scientific American reporter wrote that "mezcal is described as tasting like a mixture of gasoline, gin and electricity. Tequila is even worse, and is said to incite murder, riot and revolution."
While gin and electricity sound like excellent ingredients for a cocktail, this wasn't exactly a ringing endorsement. But today, artisanal distilleries in Jalisco and Oaxaca are making extraordinary smooth and fine spirits, using a mixture of ancient and modern technology.
Mezcal at its best is a fine, handcrafted spirit, made in very small batches in Mexican villages using ancient techniques and a wide variety of wild agaves. The piñas are still chopped and roasted slowly in belowground ovens, where they are infused with the smoke from local oak, mesquite, or other wood for several days. They are then crushed by a stone wheel called a tahona. The wheel rolls around a circular pit, propelled in the old days by a donkey, although more sophisticated machinery is sometimes used today. (This wheel, by the way, is strikingly similar to apple-grinding stones once used to make cider in Europe. Whether the Spanish introduced the tahona to Mexico is a subject of hot debate among archeologists and historians.)
Once the roasted piñas are crushed, the juice can be siphoned off and fermented with water and wild yeast for a lighter-tasting mezcal, or the whole mash, including the crushed bits of agave, can be fermented, yielding a rich and smoky mezcal that would please any Scotch drinker. In some villages, the distillation takes place in a traditional clay and bamboo still. Other distillers use a slightly more modern copper pot still that is very similar to those used to make fine whiskies and brandies. Many mezcals are double- or triple-distilled to perfect the flavor.
Some distillers are so particular about their process that they won't let visitors near the still if they've used any perfumed soaps, fearing that even a few fragrance molecules will taint their product. The better mezcals are labeled by the species of agave and village, the way a good French wine would be. Today, according to Mexico's laws, a spirit carrying the name mezcal can only be made in Oaxaca and the adjacent state of Guerrero, and in three states to the north, Durango, San Luis Potosí, and Zacatecas.
There is one ingredient that can make mezcal different from whiskey or brandy: a dead chicken. Pechuga is a particularly rare and wonderful version of mezcal that includes wild local fruit added to the distillation for just a hint of sweetness, and a whole raw chicken breast, skinned and washed, hung in the still as the vapors pass over it. The chicken is supposed to balance the sweetness of the fruit. Whatever its purpose, it works: do not pass up an opportunity to taste pechuga mezcal.
What makes tequila different? For centuries, the term mezcal applied generally to all Mexican spirits made from the roasted heart of the agave. In the nineteenth century, tequila simply applied to mezcal made in or around the city of Tequila, in the state of Jalisco. It might have been made with a different species of agave, but the method was generally the same.
During the twentieth century, tequila settled into the drink it is today: a spirit made only in a designated area around Jalisco, from a cultivar of Agave tequilana called 'Weber Blue', often farmed in large fields rather than wild-harvested, and heated and steamed in an oven rather than slowly roasted in an underground pit. (Twenty-ton autoclaves are not an uncommon sight at tequila distilleries today.) Unfortunately, the definition of tequila also expanded to include mixtos, tequilas distilled from a mixture of agave and other sugars, with as much as 49 percent of the fermentation coming from non-agave sugar. Most tequilas Americans slurp down in the form of margaritas are mixtos; it still takes a little extra effort to order a 100% agave tequila. When you do, they are well worth sampling. Some are as sweet as an aged rum or as smoky and woodsy as a good whiskey, and some have unexpected floral notes, like a French liqueur. They are perfect on their own; there's no need to pollute a fine, handcrafted tequila with lime juice and salt.
Now that mezcal and tequila have their own appellation (called a DO, or Denominación de Origen in Mexico), other agave-based spirits are claiming their territory. Raicilla comes from the area around Puerto Vallarta, bacanora from Sonora, and sotol, made from the related desert spoon or sotol plant Dasylirion wheeleri, from Chihuahua.
protecting the plants
As these spirits become more popular, a new problem arises for Mexican distillers: protection of the plants and the land. Many of the non-tequila spirits are made from wild agaves. Some distillers of these spirits see the population of wild plants as being nearly unlimited and impossible to decimate; unfortunately, this is the same belief system that led to the destruction of the coast redwoods and other wild plant populations. Although some agaves reproduce vegetatively, producing "pups," offshoots that can regrow after harvest, the harvest process prevents them from blooming. By not allowing the plants to flower, reproduce, and set seed, the genetic diversity is seriously impacted. Even the population of wild bats that pollinate agaves are diminished because the agaves are not allowed to bloom naturally.
The situation is worse for tequila, which generally comes from plants that have been farmed rather than harvested in the wild. Since only one species, A. tequilana, can be used to make the spirit, it has become a monoculture just as grapes have in northern California. David Suro-Piñera, owner of Siembra Azul tequila and an advocate for the preservation of tequila's history and the sustainability of the industry, said, "We've been abusing the species. We have not allowed the plant to reproduce in the wild. Genetically, it is exhausted and very vulnerable to disease. I'm very concerned." He attributes an increased use of pesticides, fungicides, and herbicides to the weakness of the plants themselves. Also, water is an important ingredient in tequila and other spirits; increased chemical use and degradation of the soil can pollute water supplies as well.
Already plagues of disease have devastated the domesticated agave crop, not unlike the catastrophic Irish potato famine or the wave of phylloxera that destroyed European vineyards. In the case of the agave, the agave snout weevil (Scyphophorus acupunctatus) introduces bacteria and deposits eggs that hatch into tiny larvae that eat the plant, rotting it from the inside out. Because the weevil bores inside, insecticides are largely ineffective.
Strengthening the crops and preserving wild agaves will require a combination of intercropping—the practice of interspersing agaves with other plants—protecting wild areas to increase genetic diversity, reducing chemical use, and taking steps to restore the health of the soil.