After months of failed experiments and thousands of wasted dollars, Brandon Hill believed he was finally on the verge of making liquor history.

He checked the gauges, holding steady for the first time, and peered through the window on the distillation tank, where vapor curled off the mash like pipe smoke. The toxic methanol dripped out of the run, and the good liquor swirled through coiled condensers, emptying into a glass container.

Gone was the smell of scorched sugar, replaced by ripe cherry and plum over a faint earthiness. The liquid, formerly hazy yellow, was now clear and refractive as quartz. He braced for the burn he'd come to expect, but when he tasted it, the liquor went down smooth and sweet—and Hill got so excited, he knocked the container carrying it onto the ground.

Even as it shattered, he started laughing. "I knew I'd gotten it," he remembers.

Hill, a 34-year-old white guy from South Carolina, says that with that first successful batch, he became the first person to produce traditional soju, one of South Korea's most cherished liquors, outside the country's borders. In the two years since, he's helped put something marginalized in America as "cleaning solvent" on the menus of chefs like Daniel Boulud, and created a product that's equally appreciated by soju drinkers in New York City and Seoul, where illicitly imported bottles of his brand, Tokki, now sell for nearly $150.

The only problem: Nobody can seem to agree on what he's actually made.

What Is Soju?

Despite its 700-year history, there's no consensus on the precise definition of soju. The name itself means only "burnt liquor," i.e., something that's been distilled. While there are 15 legally defined rules for making Scotch and six for bourbon, not a single regulation dictates how soju should be made, where it should be produced, or what base materials should be used in its distillation.

It's sometimes misreported that soju is the world's best-selling liquor, a distinction that actually belongs to Chinese baijiu. But for over a decade, the most popular liquor brand in the world has been Jinro, which sold 73.9 million cases of soju in 2016—more cases of liquor than Smirnoff, Johnny Walker, Bacardi, Jack Daniel's, and Absolut combined.

Much of that is consumed by South Koreans, who drink more liquor than anyone else in the world—and soju accounts for 98% of their country's liquor market, according to Euromonitor. Soju's popularity is due partly to its price—comparable to that of bottled water—but it's also driven by the liquor's cultural significance, which is difficult to overstate. Soju is expected at everything from christenings to burials, creating enough niche demand that the brand Good Day is currently attempting to corner the funerary market with a line called Missing You.

But even the people selling soju aren't clear about what the liquor actually is. According to a spokesperson for the Korean brand Hwayo, the definition of soju is "a difficult question." Hooni Kim, the Michelin-starred chef behind Korean restaurants in New York like Danji and Hanjan, which stock eight different soju brands, sounded resigned when asked what he thought the spirit was supposed to taste like. Until recently, he said, "I never even really thought about it."

Though Kim described Korea as a place "where modernization doesn't take over tradition," to him soju represents an exception. Whatever the liquor truly is has been "lost—I wouldn't say in translation, but in time."

"How do you get to the root of something," he asked later, "[when] people don't even know what soju is?"

A Brief History

It was the mid-14th century, and King U was starting to see the sense behind prohibition.

Koreans had long consumed makgeolli, a milky wine most commonly made from rice, water, and the unique fermentation starter nuruk, which was originally cultivated using wild yeast. But when the Mongols invaded in the early 13th century, they brought distillation technology from Persia that could refine makgeolli into the more potent drink eventually known as soju.

Several decades after the Mongols were forced out of the Korean Peninsula, the liquor they'd left behind was wreaking havoc. In his book about Korean liquor, Korean Wines & Spirits: Drinks That Warm the Soul, the journalist Robert Koehler quotes historical records frantically describing an upper class now "squandering their fortunes on soju and silk," and a military led by at least one general who "debauched himself with soju...gathering courtesans and the commanders beneath him to drink [it], night and day."

"Henceforth," King U declared in 1375, "[soju] shall be strictly forbidden."

It didn't work. Despite continued royal hand-wringing about soju's growing popularity ("now all consume it even at ordinary parties," wrote one advisor to King Seongjong) and prolonged attempts to ban production, soju became a part of gayangju, or homebrew culture. Families began to make and drink it at home, and many gave it away for free.

What Korean royalty couldn't do by decree, Japanese colonizers in the early 20th century nearly accomplished through taxation and, eventually, the criminalization of production. According to Koehler's estimate, there were over 28,000 soju producers in 1916; by 1933, there were just 430.

This suppression turned traditional spirits into a symbol of anticolonial resistance—students at the prestigious Korea University in Seoul, for example, would gather in front of a Japanese police station and drink buckets of makgeolli until they vomited on the front steps, shouting, "Disgusting dogs from Imperial Japan!"*—but it also shaped their production, as some Korean soju makers began to use Japanese-style distilling equipment and yeast.

* The emetic tradition at Korea University survives today, though it has been reframed as an initiation ritual that rids students of the educational legacy left by Japanese occupation. The event has led to deaths from alcohol poisoning.

Following the Korean War (1950–53), South Koreans began to reconstruct a devastated nation. Facing food shortages, strongman president Park Chung-hee (father of recently impeached president Park Geun-hye) outlawed the use of rice for anything other than food in 1965, effectively making the production of soju illegal.

In its place, commercial breweries started making a cheap product called "diluted soju," which resembled the traditional liquor in name only. It was made from pure, flavorless ethanol, mass-produced from whatever was available —tapioca, sweet potato, molasses—which was then diluted and mixed with chemical preservatives and artificial sweeteners, like saccharin, aspartame, and stevioside.

It was like selling MD 20/20 as Macallan 15. But it was also "perfectly suited for the demands of the times," as Koehler argues. South Korea, a country with virtually no natural resources, was rapidly industrializing, and would rise from the second-poorest nation in the world—GDP per capita in 1953 was $67—to become its 11th-largest economy in just over 60 years. Koehler notes that that transformation was initially accomplished on the backs of young people who moved to the cities, willing to take whatever work they could find. Soju, however nontraditional it had become, was a way to endure.

Writing in 1984, the worker-poet Park No-hae illustrated its significance: "When the night shift like combat ends...pour cold soju on our stinging chests at dawn / for our love, our fury / our hope, and our solidarity that breathes and grows / within our rugged blood, sweat, and tears."

By the time rice-liquor production was decriminalized in 1999, according to one estimate, fewer than a dozen people still made it in traditional forms.

"Traditional" Soju

Hill had been interested in making liquor since he was a kid, listening to stories of his bootlegging Welsh grandfather sleeping above his basement stills to keep warm during Michigan winters. When he realized, as a teenager, that the fractional distillation taught in his chemistry classes could be put to recreational use, Hill began teaching himself to make spirits like whiskey and ouzo. After an itinerant early twenties, he heard from a friend about a school for traditional Korean liquor opening at Kyonggi University in Seoul in 2010. It seemed like an opportunity to continue his education.

It also revealed to him a blind spot in the collective liquor consciousness: While many people in America knew quality Japanese sake and shochu existed, even Hill knew little about Korean alcohol beyond the cheap green bottles of the most popular soju brands.

As he began the two-year program, he started to understand why. Modern soju continues to be made from flavorless ethanol, produced in vast quantities and sweetened with chemicals. But at its most traditional, Korean soju is almost impossible to make at scale.

The basis of nearly all types is nuruk, a cake of wheat that contains the fungus Aspergillus oryzae—better known in the West by the Japanese name koji—as well as yeast. The fungus produces an enzyme that converts starches from rice or other grains into sugar, which the yeast then consumes to produce alcohol.

Nuruk was traditionally cultivated by leaving the cake outside to grow the mold naturally and catch yeast floating in the air. But the wildness of the production left things largely up to chance. Sometimes more of the enzyme would cultivate, leading to a faster fermentation, and different airborne microorganisms would collect on the nuruk itself. Traditionalists say that diversity gives soju its depth and complexity, but it can also lead to bad-tasting liquor.

Things get even trickier in the later stages of soju production. Even if the nuruk is cultivated correctly, it typically contains so little yeast that the mixture needs to be re-fed constantly. But opening the jars to do so brings a risk of contamination, potentially exacerbated by traditional techniques like mixing batches by hand.

While traditional producers could theoretically make larger quantities, it would be difficult to control the quality, which would necessitate taking significant losses on contaminated batches. The few producers that make certain concessions to modern methods, like automating the temperature of the fermentation or producing in a hermetic environment, don't scale up for another reason: insufficient demand.

During the country's industrialization, modern soju began its own evolution. By the time Hill arrived, the spirit wasn't just the country's most popular liquor—it had become synonymous with its drinking culture writ large.

The consumption of alcohol in Korea is an inherently collective activity,** which is evident in the etiquette that reigns at the table. Drinks are received with two hands to indicate respect, and shots are nearly always taken as a group; glasses aren't supposed to go empty, either, because of the expectation that someone else will quickly refill you when the liquor runs low. And that liquor is almost invariably cheap, mass-produced soju, the ubiquity of which has led to it being inextricably linked with all the customs associated with drinking. Every night of the week, restaurants around the country are filled with groups of people gathered around plates of anju, or drinking food like pajeon (savory pancakes) and samgyeopsal (grilled pork belly), toasting one another and filling tables with rows of empty green bottles.

** A term was recently invented to specify the practice of drinking alone (honsul, a portmanteau of "alone" and "alcohol").

"I really loved the drinking culture and the community around it," Hill says. But after spending his days learning the intricacies of traditional liquor, the scenes at restaurants at night were a little incongruous—refrigerators stocked with identical green bottles that suggested a singular definition for what it meant to drink Korean alcohol: taking shots of something sweet and cheap.

That contrast was reinforced on the weekends, when his professor would take him to different home breweries on the outskirts of Seoul, or in the rural valleys of the Jeolla provinces, where different kinds of liquor were being produced in tiny quantities that couldn't travel far beyond the regions in which they were made.

"I was getting to try this secret world that most Koreans aren't exposed to in the mainstream," he says. When he returned to the United States, "I felt like it had to exist here."

Hill arrived in Brooklyn after finishing the program with plans of opening his own bar, which he'd stock with the small, manageable batches of liquor he'd learned to make in Seoul. But when the funding dried up, he took a job as the head distiller at Van Brunt Stillhouse in Red Hook, producing whiskey and rum while continuing to experiment with different Korean spirits. When a friend asked him if he could make anything for her Korean restaurant, he was already up and running. "I pretty much just made her a liquid résumé," he remembers—small batches of makgeolli, maesilju (plum wine), and other traditional liquors. But people were most surprised by the soju, and when it started selling out, Hill realized that if he could figure out how to produce traditional soju at scale, there was an opportunity to show unfamiliar drinkers in America "just how good [it] could be."

"Traditional soju," by Hill's definition, was determined by methodology; if he adapted traditional methods to modern equipment, he felt it would still be the real thing. He found in California the only farm in the country that produced organic chapssal, a uniquely Korean sweet rice varietal, and sourced from there. Relying completely on yeast collected outside would be too unpredictable, so he isolated wild strains and cultivated them indoors. Most koji is produced the Japanese way—on grains of polished rice—because it's the easiest to regulate, but Hill grew his own on wheat to mimic the earliest approach to cultivation in Korea. Once both were in his nuruk—which he baked in a traditional oven, called a nurukjip, that he'd built from scratch—he began adapting Western distillation equipment to handle the eccentricities of traditional Korean fermentation techniques.

By the time he shattered the glass, he'd also "cracked the code" behind making his soju at scale. Then things actually got complicated.

An Old Bootlegger's View

I had been living in Seoul for two years when I first tried Tokki. Prior to that, I'd avoided soju whenever I could help it—the hangovers had come to make sense only when I noticed restaurants using leftover bottles to clean barbecue grills. Tokki was a revelation: cleanly sweet, with a complex, earthy finish, reminiscent of tequila without the burn.

Even though the brand wasn't technically importable to South Korea, some high-end bars had started smuggling bottles back from the United States and reselling them for exorbitant prices, and Hill had been the subject of curiosity in the media about an American soju evangelist. While none of those news stories criticized Hill's intentions or product, the situation raised questions for me about the meaning of tradition. In the absence of a definition, could something be a traditional Korean spirit if it was made by a white guy in Brooklyn? As I sat in restaurants in Seoul, surrounded by bottles of Korean soju made from foreign grains and imported chemicals, it seemed like a riddle created by globalization.

And so, late in November 2016, I sat outside a hanok surrounded by newly built apartments in Bukchon, one of Seoul's oldest neighborhoods, waiting for Kim Taek-sang.

Kim is one of South Korea's best-known traditional-soju producers, a 10th-generation distiller turned bootlegger, now in his third act as a government-designated national treasure. He's a doting grandfather out of central casting, with neatly parted gray hair and a flushed complexion that lends credence to his claim of tasting every bottle he makes. He led me down narrow stairs into his basement, looked at the clock—it was 11 in the morning—and poured shots of different homemade liquors. Then he began to reminisce about his days as a criminal.

Park Chung-hee's decision to ban rice-based liquor didn't stop its production in Korea, he explained. Instead, it consolidated the best home brewers into a network of bootleggers.

According to Kim, the goal was the preservation of culture, not profit. He stayed true to the techniques he'd learned from his mother, such as distilling based on the Korean zodiac calendar and keeping the temperature of the fermentation consistent through body heat, by hugging the barrels. In the past, distillers would produce their liquor in underground stills, covering them in ash to hide the smell of fermentation, near the port where their pots were fired—warm pots were considered still alive, and so able to produce better liquor.

As we drank, Kim began to fold rice dough into flowers for ihwaju, an alcoholic traditional custard. When I asked if he'd heard of Tokki, he smiled but barely looked up.

"I've heard of it, but I think it would be hard to consider that traditional."

He explained that all the methods Hill, and other producers in Korea, have adopted to scale up production and ensure consistency are the very things that render them nontraditional. The enormous size of the steel tanks, the automated temperature control, the paddles used to mix huge batches—all of these things separate the producer from the product, even if the base materials are traditional.

Soju is something you make by hand, Kim said, and that means it has always changed based on the producer, the season, and the location. The liquor is specific and intimate, and intimacy isn't scalable. By making a consistent version of something that has never been consistent, Hill and others are creating a product that's just as modern as the mass-produced versions they position themselves against.

Kim didn't seem worried about what this meant for himself, though. He's made it this far, he said; he sells nearly his entire small run each month. We poured out the last of a bottle of his most celebrated liquor, Samhaeju, a peppery, high-proof soju. It's sharply floral with a lingering sweetness, and—at least to my untrained palate—not dissimilar from Tokki.

A Case of Identity

"There's an identity crisis going on," says Jisung Chun, laughing as she fills the glasses in front of us. We start drinking as throngs of shoppers outside wander the streets of Gangnam, which, in the last 40 years, has been transformed from farmland into a neighborhood sometimes compared to Beverly Hills.

Chun is an award-winning sommelier who previously worked at the Sool Gallery, a Korean government–sponsored center for the preservation of traditional liquor. As she explains the factors that complicate any understanding of the subject, she pours shots, beginning with the most famous: Andong Soju.

First, there's the problem with myeongin, the government certification given to historically significant brands like Andong Soju or Samhaeju. While this would seem the clearest definition of "traditional," Chun says some myeongin brands cut their soju with sweeteners or other additives, undermining the legitimacy of the designation. In some cases, Chun says, grandchildren who didn't know how to make liquor inherited their family's brand certification, and had to take shortcuts to compensate for their inexperience.

We take our shots. This soju has an astringent bite and a complicated aroma, which Chun helpfully clarifies as a "moldy-basement smell" that "some people describe as very floral." This alludes to another problem: Traditional soju is an acquired taste, and therefore prone to misunderstanding.

Over the afternoon, she'll list other descriptors sometimes used by Korean drinkers of traditional soju, which include gul-pan-neh ("It's like when you wring water out of the rug—something not pure") and gol-lang gol-lang ("It's not necessarily stinky, but it's how we describe fermented fish").

These sound negative, she explains, but they're actually not. Just as some drinkers come to love the tarriness of a heavily peated Ardbeg or the barnyard funk of good Bordeaux, soju aficionados appreciate flavors that don't seem appetizing at first blush. But this is difficult to explain to many Koreans, she says, who've heard stories of dangerous "moonshine" made during colonial suppression, and wonder why they should risk drinking something that already tastes bad.

"Over time, I got training on overcoming those negative associations," she says, "so I learned to like Andong Soju." She adds, "It reminds me of sucking on something salty—like a tiny salt rock."

Then there's the problem of region. Some claim traditional soju can be made only in Korea, but Chun says that in soju, terroir is an alien concept. While certain brands are regionally specific, there's no sense that the spirit can be made well only in particular places, given how drastically it can change from batch to batch—even when produced by the same person in the same place.

Finally, there's the fact that some brands continue to use Japanese methods of cultivating koji for their nuruk, growing a Japanese-patented strain—even though Korean scientists have developed their own "national" version—because it is cheaper and more reliable. Other brands forgo nuruk entirely, opting for a Japanese-style fermentation that relies solely on koji and commercial yeast, which would seem to make their soju closer kin to Japanese shochu than anything else.

All these factors make the idea of traditional Korean soju, let alone soju writ large, difficult to pin down. Eventually, we circle back to the question of what, if anything, qualifies, so I ask her about Tokki. She stresses the value of certain brands' longevity, but also recognizes that Hill's methods are currently more traditional than those of many Korean producers.

"I feel uncomfortable calling it traditional," she says, "but I don't know what else to call it, either."

In the Spirit of Compromise

Sitting underneath faded advertisements for modern soju brands, Sanghyun Ahn offers a far less forgiving view of the traditional stuff.

"During the last five decades, we have been brewing and distilling rice alcohol in such a stupid, shabby way," he says. "It hasn't even been soju. We're just starting to make real soju, real makgeolli, real rice alcohol."

Ahn is a former consultant for the Boston Consulting Group and was once the vice spokesperson for Korea's Democratic Party. Recently, he's reinvented himself as an ambitious restaurateur and promoter of traditional Korean liquors, with designs on creating Korea's first destination restaurant.

We meet near his first effort, Mr. Ahn's Craft Makgeolli House, which features one of the most extensive traditional-liquor menus in the country. It's located in Haebangchon, a former hub for North Korean refugees after the war, which has since turned into one of Seoul's most diverse neighborhoods. Leading me up one of the area's dizzying hills, he turns into an old restaurant and begins questioning the premise of my interest in Tokki.

"Tradition itself is not that much important. I don't think so," he says. "Frankly speaking, I'm a patriot. I love Korea, but Korean soju traditions aren't that meaningful compared to French winemaking traditions. We have a thousand years of tradition, but it's not that highly developed, not that highly sophisticated."

And how could it be, he asks. Korean liquor has always been suppressed and pushed underground by kings, colonizers, restrictive legislation, and, now, the market forces of late capitalism. This doesn't mean it won't ever be top-quality, but it does require a reassessment of the methodology. "Maybe part of the future of soju can be Kim Taek-sang and those guys," he says, "but as far as the industry wants to evolve, there must be mass production."

Ahn points to the development of Scotch over the last 200 years. Once, it was thought that top quality could come only from small-scale producers. But challenges from Canadian and American whiskey producers contributed to distilleries in Scotland adopting more rigid standards for their liquor—extensive aging, no additives—while encouraging the consolidation of smaller producers into giants like Glenfiddich, which could spread Scotch around the world.

"We have to make that standard from now on, and for that standard, Brandon Hill made a meaningful approach," Ahn says. By transparently creating a product the traditional way, "He took a first step."

In the interim, Ahn bides his time, recognizing that many of the soju brands he carries aren't as stringent in their production processes as Tokki. "They add a few artificial flavors, and I accept that, because if I make too high of a standard, I can only handle three or two," he says. "So it is just the beginning."

But right now, accommodations have to be made—and in a way, considering soju's bootlegging past, that itself is not entirely untraditional.

"At the very beginning, we have to do whatever we want to do," he says. "Like the gangsters."

American Soju

Back in America, the soju market has become even more confused.

Hill declined to comment on other American brands, but Tokki was predated by the American soju brand Yobo, which is made from distilled grapes and without nuruk. Carolyn Kim, the founder, told me that she simply wanted to make a higher-quality version of the modern soju that's currently popular—a "clear, soft spirit" that's drinkable and pairs well with Korean food. She's also wondered about how to actually define the liquor itself, but isn't bothered by that ambiguity when it comes to Yobo.

"We think it's more soju than anything else," she said, "and that's the space that I'm comfortable in."

The latest American brand, West 32 Soju, launched last year, and it's nearly identical in aesthetics and price to the green-bottle brands. While it's perhaps the least traditional soju on the American market—made from distilled corn and sweetened with cane sugar, neither of which is native to Korea, and without nuruk—it's also the most affordable, and founders Daniel Lee and Maxwell Fine say that's the point. The main question they sought to answer with their product was "How can we provide a soju that's all natural, that's a cleaner version of what people are used to, and not break the bank?", according to Lee. They wondered whether the higher prices of the other American brands actually misrepresent soju as something other than a drink that facilitates a specific social atmosphere.

"They have great products, and it's really great what they're doing," Lee told me, "but does that take away from the essence of soju?"

After speaking with Lee, I sat down with Hooni Kim, the chef. He also believes there ought to be a narrower definition of soju, and, while Tokki appears at the top of his liquor menus, he admits he's not a purist, appreciating soju in all its forms.

"When I eat grilled pork belly," he says, "you almost long for [modern soju], because it does wash it down.... It's almost like French wine and cheese—there are certain dishes you just have to have soju with to make it a complete meal."

Soju has embodied so many things—history, resistance, community—that it's no wonder the spirit is so hard to parse. Considering that complexity, Kim suggests that splitting soju along some binary of "traditional" and "modern" isn't useful, because that misses what he finds interesting about Tokki.

"You taste the nuruk, you taste the fermentation, you taste the process—not just what the maker wants me to taste, but the actual process of it becoming a product," he says. "For me, that was new—exciting."

In the absence of some definition, he implies, Tokki is neither traditional nor modern; it occupies the space between two categories. It's emblematic of the process the spirit undergoes to become something else entirely.

"I don't know if that's authentic," Kim says. "But you know what? It doesn't matter anymore, because that soju—the authentic soju a hundred years ago—is dead. And whatever comes back, it has to be new again."

Editor's note: The soju brand West 32 Soju was incorrectly identified as W32 in an earlier version. We regret the error.

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