CHICAGO—For most drinkers, the first taste of Jeppson's Mal?rt tends to be the last.
"I've heard everything, from it tastes like earwax to Band-Aids to burnt hair," said Ian Penrose, a bartender at Rocking Horse in the city's hip Logan Square neighborhood.
Taste isn't the only problem for the 80-year-old, gold-colored spirit made from a Swedish recipe. Jeppson's Mal?rt can't be found outside of Chicago and a few suburbs. By the company's own admission, its Mal?rt is enjoyed by only one out of every 49 drinkers who try it. Even the company's owner, Pat Gabelick, a 69-year-old retired secretary who runs the company out of her condo on Lake Shore Drive, rarely drinks it.
Still, the liquor is finding a growing following among Chicagoans as a kind of badge of honor. A shot of it is a way to punish a drinking buddy or out-of-towner. A page on the website Flickr is dedicated to photos of people with sour looks on their faces after sampling Mal?rt for the first time. Mixologists like the challenge of making Mal?rt's bitter flavor somewhat enjoyable.
On Wednesday, Trenchermen, a restaurant in Chicago's Wicker Park neighborhood, is dedicating the night to Jeppson's Mal?rt, celebrating one of the year's busiest bar nights with a barrel-aged version of the bitter booze. Tona Palomino, the restaurant's minister of libations, decided to embrace the spirit a year ago after moving here from New York City.
"It has become the shot of choice of people who work in the industry," he said.
Mr. Penrose sees more people ordering the spirit that once was drank largely by bartenders, often well past midnight. "It has gone from an inside joke to something people are seeking out," he says.
Jeppson's Mal?rt gets its bitter taste from wormwood, which is "Mal?rt" in Swedish. The weedlike plant is better known for its role in absinthe, but was also popular in other spirits.
Ms. Gabelick, who inherited the company from her boss, says sales climbed last year by more than 80% from just a few years ago to 23,500 bottles, with annual revenue of more than $170,000. The company raised its price this year for the first time since 2004.
As for the product itself, there is little to be done, Ms. Gabelick says. It tastes OK with grapefruit juice, which does a pretty good job of masking the flavor, she says.
Ms. Gabelick seems a bit baffled by the interest in Mal?rt, which was a hobby for her boss, George Brode, a Chicago lawyer who left the company and its one product to her when he died in 1999.
"All my life I wish George had made a product I could drink," she says.
Jeppson's Mal?rt got its start when Mr. Brode landed one of Chicago's first liquor licenses after the repeal of Prohibition in 1933. He added Mal?rt to his stable of liquors when approached by Carl Jeppson, who had a recipe for a spirit favored by the city's Swedish immigrant population. Mr. Brode eventually exited the liquor business for a career as a lawyer, but kept Jeppson's Mal?rt.
George Brode had fun with the marketing and held on to Mal?rt for the challenge of trying to sell a drink many considered undrinkable, says David Brode, one of his sons.
"I think my old man loved challenges—period," he said.
Mr. Brode struggled for decades to expand the appeal of Jeppson's Mal?rt. Then Ms. Gabelick took over and didn't have money to do marketing, running the company without a computer or staff. She contracts with a distiller in Florida to make the spirit; it is sold to bars and stores by two liquor-distribution companies.
Mal?rt has had a cultish following among local bartenders. Charles Joly, beverage director at The Aviary, a Chicago bar, remembers being intrigued years ago by the rarely poured bottle at a dive bar where he used to hang out. His initial assessment of the taste: "stomach bile and dirt."
Over time, he learned to embrace Mal?rt, partly out of pride for his hometown. "It is a Chicago ingredient. There is almost a certain responsibility to find a good way to beat it into submission," said Mr. Joly.
The mention of Jeppson's Mal?rt tends to draw two reactions: confusion over what it is or a stream of stories about encounters with it.
Chris Bojanowski fell into the first category, but was intrigued, trying a shot at High Dive in the city's Ukrainian Village neighborhood. He took the shot, his face tensed and he swore.
"It's lingering. Its awfulness is throwing me for a loop," he said.
At the other end of the bar, Jim Mannion remembered the first time he encountered Mal?rt. It was about a decade ago at a bar, and two guys who didn't get along kept sending shots of it to each other.
"It's not strong. It just tastes terrible," said Melissa Luety of the spirit, which is 70 proof.
Tom Vanek says Mal?rt is a staple of his neighborhood bar, and he has been drinking it for a dozen years. Echoing a line used by fellow Mal?rt fans, he says the first three shots are an assault on the taste buds, but by the fourth the spirit starts to grow on you.
"For better or worse, I've turned a lot of people on to Mal?rt," said Mr. Vanek, a lifelong Chicago resident.
Enthusiasts of the drink held their first Jeppson's Mal?rt night earlier this year, at a bar a few blocks from Wrigley Field. Seated near the back, Ms. Gabelick sipped white wine, steering clear of the Mal?rt Manhattans and Mal?rt Mojitos. She had one regret as 20-somethings gathered around her for pictures.
She wished her old friend George Brode was there to see people toasting the bitter spirit.
"I hope he is watching us," Ms. Gabelick said.