Craft brewing is in a sour state of mind.
As the India Pale Ale frenzy of recent years calms, sour beers have quickly become "one of the fast-growing styles for craft brewers," according to Bart Watson, chief economist for the national trade group Brewers Association. A poll conducted in November reported 73 percent annual sales growth in the "Sour/American Wild Ale" category, according to Nielsen.
Sours, which are made when various bacteria are introduced to the brewing process, are also more attractive to the female consumer, Watson said. The same poll showed women are 75 percent more likely to prefer sour beer than men.
Regardless of the circumstances, Watson believes the sour market will continue to grow because they offer characteristics other beer styles don't.
"They're super refreshing on a hot day. The acidity cuts food very well," Watson said. "Sours present a challenge, but once people get over that threshold, there's a lot to like there."
In recent years (and even months), Maryland breweries have puckered up and joined the fun. We spoke to four companies to get the stories behind their sours.
Old Pro Gose by Union Craft Brewing
1700 Union Ave., Woodberry, unioncraftbrewing.com
When Union Craft Brewing debuted its Old Pro Gose ("go-suh") in July 2012, most visitors to the Woodberry brewery were immediately turned off by the tartness.
"When we first started to pour it, I'd say 70 percent of the people that would come in here would turn their faces up at it and didn't like it," said Kevin Blodger, co-founder and head brewer.
Since then, as craft-beer drinkers have become more educated and curious about different styles, Union's summer sour beer has become one of its best sellers, Blodger said. Last year, the company began canning the beer and purchased what the founders believed was a three-year supply of cans. They ran out by August.
"In the summertime, it absolutely kills for us," Blodger said.
He credits Old Pro's accessibility. It lacks the face-scrunching tartness that more-potent sours possess, and the salt and coriander notes maintain balance. At 4.2 percent alcohol content, it also won't smack drinkers in the face too quickly buzz-wise, Blodger said.
"People really seem to be digging it now," he said. "Now I feel like Old Pro is a Baltimore summer classic, at least to me."
Puck Face by RaR Brewing
504 Poplar St., Cambridge, rarbrewing.com
Former Oriole Billy Ripken inspired the name of RaR Brewing's first sour. More specifically, it was Ripken's infamous 1989 Fleer trading card that featured an overlooked expletive printed on the player's bat.
"I think that's what Billy's remembered most for, even more than his playing," said co-owner Chris Brohawn.
With a nod to the gaffe, the Cambridge brewery on Saturday released Puck Face, a dry-hopped Berliner Weisse-style beer with 3.6 percent alcohol content. Within hours, all 50 cases sold out, Brohawn said.
"We underestimated the demand," said Brohawn, whose father bought him the Ripken card when he was 11.
The cans are gone, but Puck Face is still on draft at the brewery's taproom. And at 5 p.m. today, Max's Taphouse in Fells Point will host an RaR Brewing event with multiple beers, including Puck Face.
For Brohawn and brewmaster Randy Mills, the key to their sour is the use of lemon-drop hops, a hard-to-find German strain.
"I think [a sour] should be crisp, dry," Brohawn said. "We used lemon-drop hops, so when you get that lemon-lime flavor, it's almost like a key lime pie."
Nouveau Rouge by Evolution Craft Brewing
201 E. Vine St., Salisbury, evolutioncraftbrewing.com
Evolution Craft Brewing's Nouveau Rouge is one of the more complex sours made in Maryland because of the brewing technique the Salisbury company uses — the solera method.
In layman's terms, the process consists of aging a red ale, along with souring agents, in oak barrels over different amounts of time. Then the variously aged beers are blended to create unique versions of the sour. The process repeats every six months or so, as the flavors continuously mutate.
Now in its seventh year of production, Nouveau Rouge has found fans across the country. In 2013, Draft Magazine named it one of the top 25 beers of the year. Evolution founder Tom Knorr credits the balance among the beer's tartness, its vanilla notes and the oak taste from the barrels.
"It's not one that's going to give you that total pucker face," Knorr said of the beer, which features 6.3 percent alcohol content.
Evolution releases a newly blended batch of roughly 2,000 bottles every six months, Knorr said. The sour is a Flanders red ale, a style popular within the Flanders region of Belgium, he said.
Earlier this week, Evolution released its sixth batch of Nouveau Rouge. While Knorr is excited, the beer's production technique makes him look to the future.
"It's an ever-evolving beer for us," he said. "In 20 years, there will still be some of the first beer in there that we did in 2009."
Sour Me This by DuClaw Brewing Company
8901 Yellow Brick Road, Suite B, Rosedale, duclaw.com
On Monday, DuClaw Brewing Company began bottling Sour Me This, the Rosedale operation's first widely released sour. Founder Dave Benfield is more of a "hop head" than sour enthusiast, which explains DuClaw's bitter-meets-tart approach to the 5.8 percent-alcohol-content beer.
"You have to be careful if you're trying to basically sour it up like crazy. You still have to balance with the hops," Benfield said. It was about "getting it balanced to where it has a great flavor and tartness, but it's a drinkable beer. It's not going to turn you off."
While Benfield doubts sours could reach the widespread popularity of IPAs ("the tartness is polarizing"), he believes sours are here to stay. In the near future, he hopes to release a barrel-aged sour and a sour infused with peaches and apricots.
"I think they'll continue to rise in popularity, and brewers will continue to break boundaries on what we can do with the beer," Benfield said.