In its first year, Gun Hill Brewing has rolled out its Gold ale, made for easy, extended drinking; fruity ales tailored to warm weather and an award-winning stout. None of those varieties, though, has sold as well as Gun Hill's India Pale Ale.
"Obviously, people like the flavor of it. But I think it's become so popular because there are very few beers people can see and immediately recognize," said Dave Lopez, co-managing partner of the Bronx, New York-based microbrewery.
The hop-heavy, high-alcohol brew has grown at a faster pace than the ever-expanding U.S. craft beer market. IPA sales in the 52 weeks ended Jan. 25 jumped nearly 50 percent from the previous year, according to IRI, a Chicago-based market research firm. The wider craft segment rose about 20 percent.
IPAs accounted for about a quarter of craft sales in that span. Fervor for the hop-heavy ale shows no signs of slowing.
"Everyone expects it to slow down, but it's shown incredible growth," said Bart Watson, staff economist at the Brewers Association.
Craft brewers—small, independent producers with an annual output of 6 million barrels or less—accounted for about 8 percent of U.S. beer sales in 2013, according to the Brewers Association. Though large companies like Anheuser-Busch InBev and Molson Coors still dominate the American market, craft beer continues to chip away at large breweries' share.
As consumers flock to IPAs, breweries have expanded their offerings to meet demand. IPAs continue to surge because more varieties have emerged, said Paul Leone, executive director of the New York State Brewers Association.
Recent trends include ales made with malted rye instead of barley or "sessionable" variations, Leone said. Sessionable brews typically are lighter in flavor and may have lower levels of alcohol, which means it is easier to drink several servings over a few hours.
"There are plenty of IPAs to choose from, which gives it more staying power," he said.
Gun Hill and other New York City breweries that showcase their beers in New York City Beer Week—which started Friday—have increasingly met consumer demand for IPA variety.
Gun Hill officially opened last spring and brewed about 1,000 barrels last year. It currently has two IPAs on tap in its tasting room, which is tucked behind a huge garage door in a lofty warehouse space.
Gun Hill keeps its "flagship" IPA on tap year-round and put on a stronger Imperial IPA in December. It will also unveil its smoother Black IPA and other special edition brews on Feb. 28.
Nearby Bronx Brewery rolled out its Session IPA last fall. The ale, which is less bitter and alcoholic (5 percent by volume) than a typical IPA, has become one of co-founder Chris Gallant's favorite beers for repeat drinking.
The Bronx Pale Ale, which is not an IPA, sells best for the brewery, which produced about 6,000 barrels of pale ale last year. Its new Session IPA has gained enough traction that the brewery is working to release it in its signature silver cans and keeps it tapped in its Bronx tasting room year-round.
Consumer taste has shifted to hoppy beers, Gallant said. Bronx wanted to offer a more drinkable brew in the "crowded" IPA space, he said.
"This is a beer that you can sit down with and have a couple of," Gallant said.
Brooklyn's KelSo Beer—which produced about 5,000 barrels last year—offers two IPAs. It brews its 10.5 percent alcohol Imperial IPA year-round because "everyone was wanting one," said Kelly Taylor, co-founder of KelSo and president of the New York City Brewers Guild.
While hop-heavy IPAs "have been going crazy," he has seen sentiment shift slightly to more mild ales or other sessionable styles. The new challenge for brewers, he said, is finding a way to create flavor without over-hopping the beer.
"They're a great flavor but don't always fit," Taylor said.