A few neighborhoods south, in Ridgewood, will be Jeppe’s new space, Evil Twin Brewing NYC, expected to open in July. Several small craft breweries already exist there, like Queens Brewery and Bridge and Tunnel. But Jeppe is looking to do something more over-the-top: He has acquired an old ballroom with saloon-style bathroom doors, heavy drapes and disco balls. “When we saw it it was like a party had been suspended,” Ms. Jarnit-Bjergso said.

A construction team is busy retrofitting the venue into Jeppe’s dream brewery. The courtyard, enclosed by a pastel pink wall, will become a year-round greenhouse and seating area. A side area is being turned into a barrel room where beer will be aged in wine and bourbon vessels. There, the original sign from “Twin Peaks,” the noir television series, will be on display. “When people are in here drinking, it will be good for them to have something to look at,” said Jeppe.

Jeppe visits the brewery, which is still under construction, every day. “I live two miles away and am involved in all the recipes,” he said. Like Mikkeller, Evil Twin will also make beers specific to New York City.

Because the twins claim they don’t communicate with each other, it’s impossible to know whether their brewery openings are coincidental, acts of one-upmanship or clever public-relations stunts.

“I think it’s nothing more than the fact that there are a lot of breweries coming up in New York,” said Jim Raras Jr., the executive vice president of Mikkeller NYC. “We happen to be one of them, and they happen to be another one.” (Mikkel does not comment publicly about his brother.)

Jeppe, however, called the turn of events “weird,” and questioned his brother’s motivations. “He doesn’t even live here,” Jeppe said. “He’s only been here five times.” Mikkel disagrees with Jeppe’s latter statement, saying that he has visited New York at least 50 times.