It's Brown, It's Barrel-Aged, It's ... Gin?

While many know gin for its light, bright and dry characteristics — citrusy, herbal flavors that go so well with tonic water — another gin sits at the opposite end of the spectrum. Malty, lightly tannic, and with the subtle sweetness and spice of a young whiskey, dark, barrel-aged gin is pushing the frontiers of this spirit forward.

Dark gins are distilled the usual way, then spend months or even years resting in oak barrels — the same ones used to age whisky, wine and sherry. That final step yields surprisingly complex results. The wood tones down the intensity of the juniper, and adds notes of vanilla, caramel and often baking spices, somewhere between a bourbonlike gin and a ginlike bourbon.

Dark gin appeared in the U.S. in the past five to 10 years, but the marriage of gin and oak is not new. "The Dutch have been doing this with their jenevers (a more neutral-tasting predecessor to gin) for 400 years," says Tad Henry Seestedt. Seestedt founded and owns Ransom Spirits, a distillery and winery in Sheridan, Ore., that helped pioneer barrel-aged gin in America in 2008. The same is true of European Old Tom gin, he notes, a fuller-bodied, long-lost cousin of modern dry gins that was sweeter and spicier, and was popular in the 1800s and 1900s. Historically, both were transported in barrels at full proof, then later cut with water by the bartenders.

Seestedt says a return to old-school styles and flavors is what sparked his pursuit of bringing barrel-aging back to gin. His barrel-rested Old Tom today makes up over 40 percent of Ransom's total offerings. "A lot of old classic cocktail books called for Old Tom gin (in recipes like the Martinez) and we wanted to bring it back."

Barrel-aged gins from Natasha Bahrami's private collection at The Gin Room inside Cafe Natasha's in St. Louis, Mo.

Courtesy of Natasha Bahrami

It took Ransom two years of trial batches working with friend and well-known cocktail historian David Wondrich to nail the aromatics and barreling process. "We found that if you make a gin that maintains a lot of presence of the grains and cereals used in the distilling process, it will respond much better to aging in barrels," Seestedt says.

Ransom's barrel-aged Old Tom gin currently spends eight to 10 months in toasted oak barrels, and has become the company's most popular product. "It pretty quickly became a situation where we couldn't make enough," Seestedt says. "It was just completely surprising that something we thought was going to be kind of odd really caught on."

Across the country, other distilleries are turning out their own interpretations to meet a growing demand for dark gin. In Columbus, Ohio, Greg Lehman of Watershed Distillery rests his grapefruit-heavy Four Peel gin in 53-gallon and 30-gallon bourbon barrels borrowed from their own supply, which he says mellows the bitterness and imparts hints of vanilla. The company went from turning out just three barrels' worth in 2011 to more than 800 cases a year now.

In Brooklyn, Greenhook Ginsmiths finish its barrel-aged Old Tom gin for one year in bourbon barrels, then one to three months in sherry casks. And the makers at New York City's Breuckelen Distilling have bottled four distinct batches of their lemon- and rosemary-infused Glorious Gin oaked in various wood treatments. They've settled on a robust recipe of new American oak for one to two years.

Natasha Bahrami of Cafe Natasha's and The Gin Room in St. Louis says she may have the largest collection of barrel-aged gins of any bartender in the U.S. "Anyone who's into gin can tell you how exciting this [new frontier] is. But I don't think the distillers themselves really even understand the world of barrel-aged gin yet. I have not spoken to a distiller who fully understood what their gin was going to come out as before they started the process. The spectrum is so diverse."

She uses barrel-aged gins to riff off classic cocktails like the Old Fashioned, Manhattan, Bees Knees (honey, gin, lemon) and Aviation (with crème d'violette, maraschino and lemon juice).

At Verbena, a restaurant and bar in San Francisco, bar manager Anthony Keels puts his favorite local gin in a barrel for four months, and uses it in his 13 Blooms cocktail: a stirred version of the Chrysanthemum, featuring vermouth, sage and saltwater.

Keels says barrel-aging gin for just four months keeps the botanical intensity, but rounds it out and better integrates the aromatics. "It's still very approachable. I can taste plenty of wood on it, but I feel like I haven't disrespected the gin." He enjoys it in a Negroni cocktail, which he says turns the drink into something midway between a Negroni and a Boulevardier.

No one can quite agree on whether barrel-aged gins will continue to grow as a category or even stick around. Growing competition in the gin market may mean the gap could be tightening up for new players to enter the arena. But Keels is hopeful there is more fun to be had: "The American style of gin and the barrel-aged versions have really changed the game for gin all together. It kind of takes the walls off for what a gin has to be, and allows for a lot more possibility."

Stacy Adimando is a freelance journalist based in San Francisco, Calif., who writes about food and lifestyle issues.