Published: September 17, 2015
Author: Bryce T. Bauer
Topics: Farming, Food, and Alcohol, Science, Engineering, and Invention
Locations: New York
Materials: Water, Wood, Sugarcane, Cacao
Masters: Daniel Preston: Rum Distiller
In a brick warehouse in Brooklyn, a former nuclear engineer is re-inventing—and hopefully reviving—America’s original spirit.
By BRYCE T. BAUER
Daniel Preston is a distiller with an energetic curiosity. Before he founded Cacao Prieto, he used his expertise in mechanical and aerospace engineering to launch a company that made parachutes for the defense industry and also developed the guidance system for the Cassini spacecraft. Which makes one wonder whether making good rum really is rocket science.
In the mid-seventeenth Century, Captain Henry Morgan was an English privateer who became famous for leading an outfit of pirates on ransacks throughout the Spanish Caribbean, amassing, in the process, a fortune that in 2008 Forbes estimated to be worth $13 million. Today, he is the face of Captain Morgan rum, staring out from one in three bottles of rum sold in America.
Pirates and the Caribbean; plundering and palm trees—and coconuts, and paper umbrellas, and tiki torches. For decades, rum for the American drinker, at its best, has conjured images of the tropics. At its worst, it has probably conjured something else, or little at all—unpleasant mornings and throbbing afterthoughts of rum and cokes, or any of a number of neon, saccharine tropical juices.
But rum is far more than sugar-laden debauchery. Though its origins are in the Caribbean, rum’s history is deeply entwined with the development of the colonial world. In North America in particular, it has a legitimate claim to being the United States’ original drink, enjoying widespread popularity long before whiskey. On the cusp of the American Revolution, Americans downed millions of drams of rum a year, much of it produced by distilleries located within the Thirteen Colonies.
Preston is a polymath, with technical leanings and a thirty thousand-foot view of whatever occupies him. Yet he gives the impression of someone who lives in a constant state of improvisation.
Rum production in America ceased shortly after the Revolution, replaced by that of whiskey. For the next 200 years, it remained (with a few exceptions) an afterthought in America’s liquor cabinet. In the last decade, however, amid a wide boom in craft spirits, rum—like whiskey, gin, and tequila—has taken on a new dimension of connoisseurship. In response to this trend, or as its provocateur, innovative small-batch distillers in the U.S. created a plethora of sophisticated new rums, suitable for mixing in complex drinks or sipping on their own. Today, over one hundred distilleries are producing rum in the United States, up from close to none just five years ago, said Bill Owens, the president of the American Distilling Institute, a trade organization for the craft distilling industry.
One of these distilleries is located far down an industrial stretch of Conover Street in the Brooklyn neighborhood of Red Hook, a few blocks from the waterfront and the IKEA ferry dock, in a Dutch-style, red-brick warehouse. The building looks like the type that’s long been a stalwart of the neighborhood—a way station for the bustling trade that made Red Hook, at the beginning of the twentieth century, the busiest port in the world. Three quarters of a century later, the container industry had moved elsewhere, and blight took over, leading Life magazine to name Red Hook one of the worst neighborhoods in the country. Yet by the turn of the 21st century, the industrial fossils of the boom times had become the new urban cool. The old brick warehouses have now been immaculately restored amid Brooklyn’s relentless gentrification.
Actually, the building that houses this distillery is of much newer vintage, built for the enterprises of its owner, Daniel Prieto Preston, who makes an unusually innovative rum here. Part of the reason is that this facility is one part distillery and one part chocolate factory, jointly called Cacao Prieto. The paired operations create an odoriferous mix of sharp, chocolaty aromas layered over the yeasty scent of fermenting alcohol—a beguiling combination that let me know I was near my destination when I came visiting earlier this year.
Preston’s distillery also produces Widow Jane whiskey, which workers were bottling when I arrived. Despite the building’s small size, there is equipment for both the alcohol and chocolate making operations everywhere, much of it designed by Preston himself. The clank of the bottling line reverberated off the still— an immaculate centerpiece with a silver base and a tapering copper neck that distillers reverently refer to as a “swan”—echoing throughout the tasting room. Preston brought me around to a small courtyard at the center of the building, where we were joined by the small flock of chickens Preston keeps to turn a bit of the whiskey’s grain waste into hearty eggs. (The chickens, too, were an experiment of sorts—when Preston ordered them from the Murray McMurray hatchery, he purchased an assortment of exotic breeds and has let them cross ever since.)
Originally trained as a chemical and nuclear engineer, Preston is a polymath, with technical leanings and a thirty thousand-foot view of whatever occupies him. Preston gives the impression of someone who lives in a constant state of improvisation. (Just getting him to commit to an appointment, for example, takes multiple conversations with an assistant and requires comparing calendars with an astrologer’s precision.) When he speaks, though, his voice is low and measured, with the delayed delivery that suggests very careful thinking. Which the novelty of this enterprise seemed to need.
DOWN ON THE FARM
The origins of Cacao Prieto grew out of his success with the previous company to occupy the building, Atair Aerospace, which manufactured precision parachute systems for the defense industry. In 2009, when Preston sold that company (now owned by Boeing), he found himself with some capital, a stringent non-compete clause, and a desire to do something new.
Preston grew up in New York City, but his father was born in the Dominican Republic, where his family, originally from Spain, traces its heritage back to the 19th century. Shortly after he was freed of his duties at Atair, Preston decided to meet his family in the Dominican Republic for what ended up being a bit of a genealogy trip. At one point during his visit, Preston expressed some interest in visiting a cacao farm. To his surprise, one of his relatives said, “Oh, we have a cacao farm. We haven’t been there in twenty years, but you should check it out.” He did and, he says, “I fell in love with it and took it over.”
From the comfort of his stratospheric perch, Preston prides himself on identifying waste streams, finding a use for them, and organizing the entire operation into a “vertically integrated” company (meaning an enterprise where one can control the entire production process). This allows him to use any of the operation’s byproducts himself, which creates yet another opportunity to make something new to sell. When he took over the cacao farm Preston did just that. “What most people don’t realize,” Preston explained, as we stood near bins of roasted and raw chocolate, which he would later let me smell to understand the one of the critical transformations cacao goes through, “is that chocolate is a fermented food.” And your byproduct is alcohol. “Everyone thinks sucrose plus yeast gives you carbon dioxide and ethanol,” Preston said, as a way of explaining the broad outlines of fermentation, but actually “there are fifty-two steps between there.”
Alcohol is produced in fermentation when yeast — either ambient yeast from the air or that introduced deliberately by a beer, wine, or spirits maker — feeds on sugar and converts it to alcohol. The sugar can come from anywhere: for wine, it comes from grapes; for cider, it comes from apples or pears; for beer, it comes from grain, once those grains have been germinated or “malted.” (For dandelion wine, which my mother claims my great-grandparents made, it comes from, well, dandelions.) With chocolate, surprisingly, that sugar does not originate in the cacao seeds themselves but from the pulp that surrounds the seeds. In tropical environments, that pulp has a tendency to spontaneously ferment in a mere four to six hours.
In cacao, that spontaneous fermentation develops flavor in the seeds, which are then roasted to produce chocolate. For most chocolatiers the role of that sugary pulp ends there—they, after all, are in the business of selling chocolate not alcohol. As a result, many chocolatiers regard the leftover alcohol as just that: a byproduct to be discarded. Since their intention isn’t for it to be drunk, they don’t give the alcohol much care. (There are exceptions, though. New World Spirits in New York has been buying cacao pulp recently from growers in Peru, Ecuador, and the Dominican Republic to produce a new liquor called Solbeso.) Without careful attention, though, the fermentation will literally run wild—with whatever yeasts and microbes have ended up in the mixtures. The result is a fermented liquid that, if consumed, tends to be “pretty rank,” Preston says. “It ends up being more a skanky vinegar than a nice alcohol.”
“You wouldn’t have a winemaker stomp his grapes in the mud and hope it tastes good in a week. You try to do it in a very clean way, and that’s the philosophy we brought to cacao fermentation.”
But it is alcohol. And just seeing it got Preston wondering whether, with a little care, if it could be turned into something that someone might love to drink. In other words, perhaps this was an opportunity for an entirely new kind of spirit: one made from the juice of his own cacao fruit.
Drawing on his background in chemical engineering, Preston tried to control the cacao fermentation with a “biopharmaceutical reactor.” The device—which looks like a giant metallic medicine capsule, with a porthole held down with enough bolts to sequester the bubonic plague—is typically used in drug manufacturing to precisely control how microorganisms interact with chemicals. His goal was to precisely break down, understand, and organize the fermentation process in ways that chocolate makers had rarely done before. Once he had some insight into how cacao juice fermentation really worked, he took what he had learned in the lab and brought it back to his cacao farm.
As he developed his system, Preston was struck by the contrast between the haphazard approach to fermentation practiced by chocolatiers and the more careful methods used by winemakers, who want to keep their unfermented grape juice free of unpleasant pathogens. “When I started this, my first thought was that you wouldn’t have a winemaker stomp his grapes in the mud and hope it tastes good in a week,” Preston said. “You try to do it in a very clean way, and that’s the philosophy we brought to cacao fermentation.” In essence what he was producing was like a wine or a cider; it was the fermented juice of a fruit, but instead of that juice coming from grapes or apples, it came from cacao.
Unlike wine or cider, however, Preston found there wasn’t enough sugar in the cacao fruit juice to produce the requisite amount of alcohol needed to preserve the beverage, and thus keep it from going bad. Moreover, he learned that sugar levels in cacao fruit vary considerably—a condition antithetical to the precisely controlled production process Preston was seeking. To remedy the problem, he added some sugar from sugarcane—the starting point for the making of rum. Then he fermented the combination, which raised the alcohol content as well.
IT’S NOT AN ART
When yeasts consume sugar in a mash or wash, they produce a number of different chemicals that can have a significant influence on the final aroma and flavor of the spirit. Called congeners, some of them are delicious, others putrid; the exact mix depends on several variables — a word Preston uses frequently when talking about distilling — such as temperature of the mash and the variety of the yeast.
People can perceive flavor and aroma compounds even if they are only present in amounts of a few parts per billion. So when a distiller creates such a compound during fermentation, it impacts the final product. “What makes a master distiller is fermentation,” Preston says. At Cacao Prieto, Preston uses a refrigerated room in the distillery’s basement for his fermentation. By chilling the wash this way, he’s able to slow the action of the yeast, extending his fermentation to four to five days, instead of the eighteen hours typical at larger rum distillers. Doing so changes the chemicals the yeast produce.
Preston believes so much in the importance of controlling the temperature in a mash that when he gives lectures on the science of distilling at the American Distilling Institute, he passes around samples of rum fermented at different temperatures. At some, the audience will remark that notes of honeysuckle predominate, in others banana bread. Once they’ve speculated on the difference, Preston will reveal what he changed: the fermentation temperature by a mere one-degree Celsius. “I go that extra one-degree difference and all of these genes change and all of my chemical spectrums change,” Preston said.
This lecture, ostensibly on the art and science of distillation, Preston considers essentially an advanced science class. It even includes the requisite Powerpoint: “The first slide is: if you’re here for the art, I am sorry to say, there is none,” he says. “It’s only art if you don’t know what your variables are and have to use your sixth sense to replicate it.”
Preston’s rum differs from that found on most liquor-store shelves, not just for the fastidiousness of its fermentation, but also for the way it is distilled.
Preston uses a pot still, which, in many fundamental ways, resembles the design of stills in use since antiquity and now preferred by many craft distillers. These require multiple distillations, but they also allow more of those flavor- and aroma-producing chemicals to make it into the final product. (Large distilleries of course look for ways to speed and simplify their operations, so they tend to use “continuous column stills,” which can produce a high-proof spirit without multiple distillations.)
Preston has also outfitted his still with a computer-controlled system that allows him to isolate and separately bottle tiny portions of the distilling run. These segments, called cuts, means he can focus on specific flavors—say, honeysuckle—in the liquor that would otherwise be lost if they were mixed together.
“If you’re here for the art, I am sorry to say, there is none,” Preston explains in a lecture about distilling. “It’s only art if you don’t know what your variables are and have to use your sixth sense to replicate it.”
All together, this small-batch system and ability for precise control, allows Preston to indulge his passion for experimentation. As much as he talks about consistency, he isn’t interested in doing the same thing over and over again. Preston has already produced a few rums that push even more boundaries, including a chamomile rum that won a silver medal at the San Francisco World Spirits Competition. He’s also produced rums made from the mixture of his rum and his cacao. Named after family members, his Don Rafael Cacao Rum and Don Esteban Cacao Liqueur are then aged in oak barrels.
Preston does add some sugar after distillation to sweeten his Don Esteban Cacao Liqueur—a practice that has, when done in excess, contributed to rum’s reputation as a vulgar party drink. Nonetheless, Preston has managed to create a balance that spirits critic Lou Bustamante wrote in Wine and Spirits magazine helps “take the edge off cacao’s natural bitterness” but is not overly sweet. He has also started using his whiskey barrels to age his some of his rum, in an effort to bridge a yawning gap between the popularity of the two spirits. (There are twice as many distillers of whiskey now in America as there are of rum. Even at Cacao Prieto, whiskey is its biggest seller.)
Whereas fermentation can be seen as the pre-industrial method of alcohol production —it can even occur just fine without human interference — distillation is firmly a mechanical, and deliberate, process. See sidebar.
Any alcoholic liquid that has been distilled is based on what it’s made from: whiskey comes from the distillation of beer; brandy, that of wine or cider; and rum, that of fermented sugarcane or any of its byproducts.
The new drink that Preston was making didn’t fit into any of those categories, however—it wasn’t exactly a brandy, because he’d used some sugarcane; it wasn’t precisely a rum either, because he’d started with cacao fruit juice. It was, more or less, a rum-brandy hybrid. But to Preston it was a science experiment that got him even more interested in alcohol production.
A COLONIAL CRAZE
While the path that led him to his rum-brandy hybrid started with a painstaking attention to the fermentation of cacao, once he got there and decided to start making rum, he applied an equal fastidiousness to that one of rum’s classic ingredients—as defined by its Caribbean heritage.
Like the region’s other islands, Hispaniola—the island shared today by the Dominican Republic and Haiti—was transformed by the development of sugarcane, which followed European colonization. All the Europeans wanted from the sugarcane was its crystalized sugar. When sugar is refined through boiling, however, it leaves a dark-brown and viscous liquid behind called molasses. As sugar production took over the Caribbean, planters found themselves with vast quantities of essentially worthless molasses as a byproduct. At first they disposed of it in feed for their livestock and issued it in rations to their slaves. When that didn’t even get rid of all of it, they dumped it into the sea.
While the molasses could not be further refined, it still contained sugar, the precious precursor to alcohol. Once the Caribbean sugar barons built systems for the alchemy of distillation, they suddenly found themselves with a profitable outlet for all that waste.
Soon rum production became as important an income source for the Caribbean planters as the crystallized cane sugar itself—and a still as necessary a piece of equipment on a plantation as a sugar refinery. (Preston, whose family also owned Dominican sugar fields prior to the dictatorship of Rafael Trujillo, suspects he isn’t the first in his family to distill rum: he has a hydrometer, used to measure alcohol content, that was once owned by one of his great grandfathers.)
Once the Caribbean planters and merchants got a taste of rum, it quickly coursed through the veins of the colonial economy, spreading its heady effects throughout the empires, but primarily to the colonies on the North American continent.
For many Caribbeans molasses, with its new-found application to rum making, became the primary item of trade. By the mid-eighteenth century, just over a century since rum’s popularization, the thirteen American colonies were importing well in excess of four million gallons of molasses a year. To process it all, rum distilleries opened up all over the Eastern seaboard — in Massachusetts alone there were more than sixty, which conservative estimates claim issued nearly one-million gallons of rum annually.
When the American Revolutionary War broke out, tea was not the only taxed item that provoked rebellion. Molasses, too, fell into dispute. Soon, molasses and rum imports into the thirteen colonies plummeted. Ultimately, though, the reason for rum’s death was cultural, identified as it was as the libation of a dependent people. “Following the war, rum took on a whiff of national weakness and vulnerability, and became a small emblem of financial imprisonment,” wrote Wayne Curtis in his history, And a Bottle of Rum. As a result, the newly freed Americans began drinking whiskey made from grain grown by honest hardworking Americans. Rum became an afterthought.
The end of colonialism in the Western Hemisphere led to a transformation of the rum industry in the Caribbean, which in turn spawned the rum industry familiar to modern drinkers today: one dominated by a few large distilleries issuing cheap rum suitable for sugary drinks.
Rum after the American Revolution was identified as the libation of a dependent people. So newly freed Americans began drinking whiskey made from grain grown by honest hardworking Americans. Rum became an afterthought.
One thing that did not change, however, was the use of molasses left over from sugar production. Historically, rum distillers have tended to use the lowest grade: blackstrap, which is also known as “third boil” because it’s made from the third and last boiling of the molasses for sugar extraction. When Preston was setting up his distillery in Brooklyn, he vowed to never use blackstrap molasses. “That is basically industrial waste that sugarcane companies have to pay people to pick-up and remove,” Preston said. Instead, he turned to first-boil molasses made from organic sugarcane grown in the Dominican Republic.
“The results were mind blowing,” he says.
Preston found the first-boil molasses, which contains more sugar and is less bitter than blackstrap, gave his rum a floral note, reminiscent of the aromatic cacao fruit juice and sugarcane rum-brandy he had started out making.
“We like making perfumey rums,” he explained. “If you look at what influences whether you like the way something tastes, smell is more important than taste, so when we produce rums we are chasing aromatics.”
THE COLOR OF WHAT’S IN YOUR GLASS
“Rum is the wild, wild west,” said Martin Cate, the owner of the San Francisco bar Smuggler’s Cove, which has in stock nearly 550 different bottles of rum. “It’s made in over one hundred countries, on every continent on earth except Antarctica. Everybody has his own styles, techniques, methodologies; it has very little in common other than its origin within the sugarcane.”
One particularly frustrating source of confusion, Cate said, lies in the fact that color manipulation has traditionally been more common in rum production than with other spirits, such as whiskey, where it is seen as a more deceptive practice. As a result, rum is typically sold in “white,” “light,” and “dark,” styles—blunt terms that can mean very different things based on the producer. Unlike whiskey, when a consumer picks up a bottle of rum and sees that it is brown, that may not (though it can) be an indication it was aged in wood—the color could just be caramel coloring, or a combination of barrel aging and caramel coloring. Conversely, some rum, in particular that from Puerto Rico, that is aged in wood is later charcoal filtered to strip out the color, making it look like a white, unaged rum. “Getting that information across to the consumers is a real challenge,” Cate said.
To Preston, however, the issue is more straightforward: caramel coloring is simply “a cheat or deception,” and he has vowed never to use it.
Small craft distilleries like Preston’s are especially poised to contribute to that variety because they aren’t beholden to the demands that face much larger operations. By way of comparison, he recalled visiting a distillery for Brugal, one of the Dominican Republic’s flagship distillers, which produces more than a million bottles a day. “It was like looking at a giant petroleum factory on Mars,” he said. “It was just ridiculous.”
Preston is able to resist some of the pressure to adopt the techniques of industrial produces as well, because he benefits from the premium mark position of craft rums—with bottles of Cacao Prieto’s rums retailing for around $50, double that of well-respected rums from larger producers.
This is not to suggest that the big boys couldn’t make a rum that deserves to be called a craft spirit. “To me,” Preston says, “craft has nothing to do with size, it has to do with your being geeks in your industry, being obsessive perfectionists, just cutting no corner. It doesn’t matter whether I’ve got a fifty-gallon still or a five-thousand gallon still, if I do everything to perfection, it’s craft.”
Bryce T. Bauer is a freelance writer, documentary producer, and curious drinker. He is based in New York City.
For more on the subject…
For more on the long history of rum and how it helped transform the New World, plus a few cocktail recipes to savor as you read it, check out Wayne Curtis’s book, And a Bottle of Rum: A History of the New World in 10 Cocktails.
If you find yourself thirsty in San Francisco, Smuggler’s Cove has one of the most extensive rum lists in America, and for those with the fortitude, a “Rombustion Society” that challenges drinkers to climb the rum tasting ladder all the way up to 300 different rums (not on the same night, of course).
In New York, though rum partisans are still waiting for a truly expansive temple to the spirit, the recently opened Mother of Pearl captures the islands in a space as luminescent as its namesake.
Topics: Farming, Food, and Alcohol, Science, Engineering, and Invention
Locations: New York
Materials: Water, Wood, Sugarcane, Cacao
Masters: Daniel Preston: Rum Distiller