Last night you bellied up to a River North bar and took a mystery shot at the urging of your coworkers. The bizarre taste—first the pungency of gasoline, then the bittersweet tang of grapefruit—left you grimacing. Little did you know you’d stepped into a local brand battle.

At the center of the controversy: malört, a wormwood-based drink that comes from Sweden. (Malört means “wormwood” in Swedish.) Similar in composition to absinthe, the liqueur traces its local roots back to the late 1800s, when a Swede named Carl Jeppson brought his recipe for the mouth-burning stuff to his new home in Chicago. In 1934, he sold the recipe to a local lawyer, George Brode, who started the Carl Jeppson Company. Brode died in 1999 and left the company to his secretary, Patricia Gabelick, now 69, who still runs the company and says she’d rather sip Manhattans if given the option.

Jeppson may keep its century-old recipe under lock and key, but it has had to fight for exclusive use of the name malört. A decade ago, no one cared; hardly anybody drank the stuff. But the mixology trend, plus a growing fondness for classic liquors, prompted tastemakers such as Brad Bolt, managing partner of Bar Deville in West Town, to take another look. “We were going through two bottles a week [in 2009],” Bolt says. “Now it’s nine.” (Gabelick says revenues doubled from 2009 to 2012 and the company sold 4,500 cases last year.)

With popularity came competition. In 2012, Chicago’s Letherbee Distillers, which makes a popular gin, cooked up a version, R. Franklin’s Original Recipe Malört, with Violet Hour vet Robby Haynes. Hard on its heels came Anguish and Regret Malört from FEW Spirits in Evanston and a “malört cousin,” Bäska Snaps med malört (a bitter schnapps with distilled wormwood), from Louisiana maker Bittermens.

Gabelick knew she had turf to protect. In January 2013, she filed a registration with the U.S. Patent and Trademark Office to take ownership of the malört name. “When you say malört, everyone assumes you’re talking about Jeppson’s,” she argues.

Problem is, there’s not much precedent for trademarking spirits. Take the efforts of the Polish distillery Polmos Białystok, maker of zubrówka (a type of vodka), which tried to trademark that name in 2006. Its lawyers argued that the word, which means “from the bison,” referred to a key ingredient: bison grass. The USPTO ruled that zubrówka is a generic liquor. The company’s claim was “similar to a company trying to [trademark] ‘vermouth,’ ” says Robert Lehrman, a lawyer at Lehrman Beverage Law who has followed the malört proceedings.

Last May, the USPTO rejected Jeppson’s application. The firm fought back, submitting a company history, articles, and affidavits from 22 bartenders arguing that the word refers exclusively to its recipe. “The only reason malört is considered as an alcoholic beverage is because of this product,” says Jeppson’s lawyer, Bill O’Donaghue.

In October, the USPTO finally approved the trademark. The competing distilleries had until February to file an appeal; they decided instead to change their liquor names. Around the time you hold this magazine in your hands, FEW will have dropped the word malört, and Letherbee will have renamed its version bësk (Swedish for “bitter”). Bittermens, meanwhile, got a pass—Jeppson agreed that the malört on its bottle is descriptive text and not part of the name.

The turf war has arguably benefited all makers: Heightened awareness of the liqueur has prompted bartenders from Chicago and beyond to challenge themselves to come up with cocktails that use all varieties of it and are actually palatable. But even combined with citrus juice, malört is definitely an acquired taste.

Ranking the Malörts

Chicago staffers tasted them for you—back when they were all still called malört. (The FEW version was sold out citywide at test time.)