In the 11th century, Bruno of Cologne, a renowned cleric and intellectual from a noble German family, rejected the chance to become a bishop. Forswearing the career bump of higher placement in the Church, he instead went into the snowy wilderness of the Chartreuse Mountains in France and built a remote retreat, founding a cloistered order that over nine centuries has remained perhaps the strictest and most austere in Catholicism. Even today, postulants who enter the order, which has chapters around the world, mostly spend their days alone, in spartan cells in prayer and contemplation, mixed with some manual labor. The monks go to sleep early and wake in the middle of the night to pray for several hours together. They rarely speak and eat a simple, humble diet.

Elements of life inside the Grand Chartreuse monastery were captured in Philip Gröning’s 2005 documentary “Into Great Silence.” Stretches could be mistaken for stills, what’s happening on-screen is so slow and quiet. A robed monk in his cell prays for long minutes, motionless on the hard wood kneeler. Snow falls. Light shifts in a corridor. Not until 20 minutes in do you even hear human voices, of the monks chanting nighttime prayers. At one point the director captures, far above, a plane flying overhead. Buglike and too far away to hear the engine, the enormous machine and its world of commerce and motion are dwarfed by the light and silence of the monastery.

“Never reformed because never deformed” is a descriptor commonly applied to the order, which is often symbolized by an icon: the cross set atop a globe, surrounded by seven stars representing St. Bruno and the six disciples who founded it. It is the visual representation of a Latin phrase, stat crux dum volvitur orbis, “The cross is steady while the world turns,” reflecting the order’s belief in the eternal truth of Christ amid earthly chaos.

The order has managed to survive, financing its existence in part through its possession and refinement of a centuries-old botanical recipe for an “elixir of long life.” That elixir evolved into Chartreuse liqueur, which in recent years has become a sought-after staple for craft cocktail makers.

The order partners with a company of laypeople who assist with distillation and handle production and marketing. Bottles of premium green and gold Chartreuse sell for $50 and up, the aged iterations for well north of $100. The spirit and its story are cherished by bartenders around the world. Some have even tattooed tributes to the alcohol on their bodies.

But as the spirit’s popularity has soared, the laypeople who run the company find themselves walking a thin green line. They must market and sell the liqueur without betraying the values of the monks who create it — the only people who know the full recipe.

It may seem odd that an order as pious and ascetic as the Carthusians relies on making premium booze to survive. But while the Bible warns against drunkenness, the Judeo-Christian tradition doesn't condemn alcohol. Wine is central to the ritual of communion. Jesus' first miracle was turning water into wine — and that story makes clear he makes premium stuff.

Michael Holleran, a Catholic priest in New York and a former Carthusian monk who supervised making the liqueur in the 1980s, also points out that Chartreuse wasn’t originally consumed for pleasure, but as a medicine. “The formula, undeveloped as it was, was originally given to the order because monks were the apothecaries of the time,” Holleran says. “In the Book of Wisdom, it speaks about Solomon having that kind of knowledge. Spiritual people were supposed to have the secret knowledge of plants and the forces of nature.”

It wasn’t until the mid-1800s that liqueur versions were released. The concentrated medicinal iteration, Élixir Végétal de la Grande-Chartreuse, is still sold in France. Tim Master, senior director of spirits for Frederick Wildman, the current American importer, says he has seen it used in rural areas for afflictions from digestive issues to bee stings.

Master says a copy of the original document for what became the recipe for Chartreuse still exists in the monastery, “and unlike a typical food or drink recipe — you know, ‘two ounces of this, three milliliters of that’ — it starts in Latin and it says, ‘Pick herb at midnight, allow to macerate till morning dew.’ ”

It took “basically 130 years” of research and development, he says, for the monastery’s apothecaries to turn the information from the manuscript into an actual recipe, and longer still for that recipe to be turned into liqueurs.

The 130 botanicals that create the flavor of the liqueur are sorted by two monks, the only people aside from the father of the order who know the full recipe. Dom Benoit and Brother Jean-Jacques have been doing it for years now; both, I learned, are training monks who will eventually replace them. The herbs are sorted within the monastery, then bags of herbs, labeled only by number, travel to the distillery, now in Aiguenoire. There, distillation is done by laypeople with the monks assisting, before the liqueur goes into huge casks to age.

The two monks are the only members of the order directly involved in the production of the spirit. In taking on the task, their lives become slightly more worldly; they must interact with secular people and leave the monastery regularly to help make the liqueur. They don’t give interviews, but they forsake a purely solitary spiritual life to do a chore that enables others to live that life fully.

“It’s kind of a penance,” says Holleran. “They’re given that job, and they do it out of obedience and devotion to the order, but generally it’s not a job that they would have picked.”

How to describe a spirit flavored with 130 secret herbs and spices? Both green and yellow Chartreuse are sweet, but at 110 proof, the green is bracingly alcoholic, with notes that seem to shift on the palate, sometimes leaning toward anise and tarragon, then cinnamon, ginger and black pepper. The milder, more honeyed yellow is 80 proof.

The bigger question has been how to sell it. Europeans have a long history of drinking herbal liqueurs as aperitifs and digestifs — think German Jagermeister, French gentian liqueurs, the vast range of Italian amari. But for many Americans, especially in the years after Prohibition, Chartreuse was a hard sell.

An amusing range of old ads from Schieffelin & Co., the former American importer of Chartreuse, seems to be casting about for the right lure. Promotions of its origins, showing robed monks leaning over casks? Check. Ads that focus on its expense and luxury? Check. Ads suggesting Chartreuse has mystical, even aphrodisiacal qualities? Check. In the 1970s, the importer had some success with the younger market: Ads featured a glowing green cocktail called Swampwater and focused on the spirit’s high proof. “More bang than a Wallbanger, more fire than a Sunrise,” explained one ad.

These ads predate Chartreuse president and CEO Emmanuel Delafon’s involvement with the company (he wasn’t born when they were circulating), but he agrees that if the monks at the time didn’t object to these ads, it’s probably because they never knew about them. Holleran had no idea they existed. And while the monks will never wander into a bar to take offense at a particular promotion, the leadership of the company is leery of doing anything to damage its working relationship with the order.

Chartreuse might have continued fumbling for a loyal American market were it not for the cocktail renaissance of the early 2000s. Moving away from the sour mix and sugary drinks that were the hallmark of the late 20th century, bartenders had begun delving into old cocktail books, seeking flavor and complexity, learning recipes that had all but disappeared.

Among them were many — the Alaska, the Widow’s Kiss and, perhaps most celebrated, the Last Word — that called for Chartreuse. As the cocktail movement spread, more bars started mixing with it, and more people started learning about it. Many bartenders were smitten with the spirit. Today, the United States is the top market for green Chartreuse.

The liquor may have traveled the world, but its Carthusian makers have mostly managed to remain apart. Master recalls visiting Chartreuse a few years ago, with some American bartenders in tow, when they met the monks who make the liquor. "And the Brother says, 'I have to ask ... what are you doing with Chartreuse that makes me so busy?' And they said, 'Well, we make cocktails.' And the Brother said, 'What's a cocktail?' "

Over the years, I’ve heard many stories about Chartreuse, many of them untrue or shaded with error: That the monks forage or grow all the herbs that go into the liquor. That Chartreuse is singularly responsible for global shortages of certain herbs. That the liquor is blessed by the monks, making it a kind of high-proof holy water.

On the grounds of the new distillery in Aiguenoire, I asked Delafon about these stories, and about the company’s reputation for silence. “You have hit upon a paradox of Chartreuse,” he said. “The less we say, the more people talk about us.”

It’s sort of genius: In this era of social media, a brand’s mythology can become a selling point without the company doing much at all. And if part of what people love about Chartreuse is the idea that they’re drinking magical healing #monkjuice, should the brand really try to change that?

For Chartreuse, the answer is increasingly yes, even if that means not marketing in ways previous leadership might have permitted. The company has occasionally had to intervene — for example, when some clever marketer has decided to promote the brand by dressing up as a monk to hand out shots. And there are some typical liquor marketing tricks they of course avoid, Delafon says. “You’ll never see girls in shorts with shots. That’s not Chartreuse.”

The brand has restrained itself in other ways. The glass bottles of Chartreuse have long been embossed with a stylized version of the cross atop the globe. “If you listen to any marketing manager around the world,” Delafon says, “they would put it on everything.” Instead the brand has gone the opposite direction, asking importers and representatives to stop using that icon on brand swag. It is not a logo, and the Carthusian order is not about Chartreuse. Quite the reverse: Chartreuse exists to support the order, and if the monks decide that making liquor isn’t the best way to do that, everything could change. “Maybe if we are not good enough to protect the business,” Delafon says, “they’ll decide to do something else.”

That is assuming the monks will voice their disapproval. A member of the order attends some of the company meetings, but he rarely speaks — partly because of the legal structure that separates the company from the order, but also because silence is the monks’ way of life. “It’s always interesting to understand how a monk will tell you things, because they aren’t talking,” Delafon says. “It’s sort of a silent approval. If they say nothing, if they are silent, it means they are agreeing.”

On rare occasions, concerns have come up. Holleran says that during his time in France, the father of the order would express mild misgivings around the extravagance: “Should we be making luxury alcohol when we’re the poor monks of Christ?” But Holleran also said he personally felt honored to be making something so high quality.

The brand can’t control the behaviors of those it doesn’t employ, though, and those who love Chartreuse sometimes integrate it onto their bodies in ways that cause discomfort at the company. Isaac Schmitt, the guide who showed me around the cellars in Voiron where some of the liqueur is stored while it ages, said they regularly see bartenders with tattoos of the icon.

"I'm not so keen on it," he said. "We had a guy come on the tour who had a massive globe and cross on his forearm, but he had no idea what it meant. We even had someone who had Father Benoit's face tattooed on himself."

The Chartreuse tattoos sported by bartenders around the world come in all sorts of forms — some simple, some ornate, often a mixture of sacred and earthly imagery. Gordon Agnew, a former bartender now based in Melbourne, Australia, has two. One is of a male torso, minutely detailed with curls of belly and inner-thigh fuzz, sporting a pair of brightly colored Hawaiian briefs. Tucked in the waistband is a pint of green Chartreuse, its globe and cross icon clearly visible. In conceiving the image, he told me, he and the tattoo artist decided on an image of his alter ego in his drinking days: Captain Chartreuse, the joke went, had the power of memory loss, could make money disappear and “always ended up smooching someone he shouldn’t.”

The other tattoo, the globe and cross, is on his hand. He got it because he found inspiration in the motto, “The cross is steady while the world turns.” Now two years sober and married, he “used to think it was some deep metaphor for bar work,” he emailed me. “Like, you need to be stable while working in the chaos of a busy bar.”

Delafon knows the brand has to strike a balance in how it does — and doesn’t — promote Chartreuse. If the company says no to every means of marketing, “you can’t develop the brand and you can’t be in the bars. And it’s true, the bars are not maybe the holiest place on Earth. But this is real life,” Delafon says. “And this is what the monks are here for — they are praying for mankind. Bartenders are part of the people they are praying for.”

While the order contemplates divine mysteries, it continues to provide an earthly one: the liquor itself, strong, silent, carrying only the meaning each person brings to it. In a way, monks and bartenders share at least one understanding of Chartreuse, though they may interpret the notion differently. As American prophet Bob Dylan put it: You gotta serve somebody.

M. Carrie Allan is a writer in Hyattsville, Md. Her columns on spirits and cocktails appear regularly in The Washington Post.