Flipping a dive bar into something more respectable can be inherently risky. (See: Hawk ‘n’ Dove.)

Regulars often retreat as payback for fiddling with their favorite watering hole, while newcomers might keep their distance out of fear of the unknown.

But sometimes the new concept and the surrounding community instantly click, which appears to be the case at the rapidly blossoming whiskey den Barrel (613 Pennsylvania Ave. SE).

Gone are the ratty booths, flavored vodkas and ho-hum pizzas that accommodated cash-strapped Capitol Hill denizens who looked to the former 18th Amendment for sanctuary. The renovated space boasts exposed brick walls and better lighting and features reclaimed wood nearly everywhere you turn, including the ceiling.

The vision of a swanky liquor lounge an 18th Amendment barkeep shared several years back has finally been realized by Elixir Bar; the nattily appointed subterranean lair (So long, dank Keyhole!) welcomes guests to a handful of high tops, a clutch of larger tables and a miniature bar, all facing a glass-enclosed cellar stacked floor to ceiling with the establishment’s mounting collection of “brown water.”

According to Brad Ingwell, area director for the Capitol Hill group that oversees 201 Bar, Union Pub and Barrel, there’s no “magic number” the owners are trying to reach in terms of their diverse bourbon, rye, scotch and whiskey holdings. “One hundred and fifty just happened to be the number we landed on,” he said of the current catalog. “If there’s something we want to add, we’re just gonna do it.”

That built-in flexibility has allowed management to amass everything from standard bearers (Laphroaig 10-year-old scotch) and cult classics (Pappy Van Winkle) to up-and-comers (Balcones Distilling out of Texas). It also allows Ingwell to evangelize a bit — as he’s wont to do when discussing his current favorite bourbon, produced by Breckenridge Distillery.

“I think its absolutely unbelievable; just the right amount of spice, just the right amount of burn. I’m just surprised how many people don’t know them,” he said of the relative unknown.

What’s been even more astonishing is the zeal with which locals have embraced the signature barrel-aged cocktails.

Per Ingwell, the powers that be presumed that traditional liquor and craft beers would be their bread and butter. But the cask-aged beverages have proven to be a huge hit.

“We’ve actually sold more of the barrel-aged cocktails than we ever thought we would,” Ingwell shared.

Though the project has already exceeded expectations, Ingwell admitted it was somewhat jarring watching staff dump bottle after bottle of pricey Brancamenta (an imported, mint-flavored liqueur) into that first round of barrels. “We probably dumped a little too much money into one batch,” he opined.

Given that the aging process for each “cascading” beverage can run anywhere from two weeks to several months, Ingwell said the greatest challenge is plotting out the successive flavor profiles to build upon.

“They’re all designed to lead into the next one,” he said of the correlation between the specialty pours.

Most recently, the Brancamenta-filled barrels had to give way to a ready-made mint julep set to debut just in time to sate Kentucky Derby watchers.

We missed the mint julep, but did slurp our fair share of Brancamenta Buck. The curious cooler hit us like a mega blast of Binaca; the marriage of mint and ginger produced a slightly medicinal burst which dissolved into a spicy-sweet finish.

A tumbler of Brava Moda was more enticing. Smoky mezcal leads the charge. But as the complementary elements co-mingle, vanilla undertones and rum sweetness emerge. By the time the giant ice cube dwindles a bit, it’s cherry soda with a boozy bite.

The kitchen, helmed by Executive Chef Garret Fleming, is equally adept at bucking tradition.

A veteran of the nose-to-tail operation at The Pig, Ingwell noted that Fleming hand-crafts most everything in-house except for the Benton’s smoked country ham (Tennessee), Edwards’ Surryano ham (Surry, Va.) and some potato buns procured from neighboring Lyon Bakery. Fleming is purportedly excited about stepping up his charcuterie-making, but needs to clear some procedural hurdles — “There’s just a couple of licensing things we need to do,” Ingwell asserted — before going crazy with fermented sausages and the like.

In the meantime, Fleming has free rein to make his own fun via the trim but adventurous main carte.

“For the most part, we just leave it to him. It’s his menu,” Ingwell said.

Fleming gets his Lowcountry on via selections like slaw-topped, pulled-pork-stuffed sticky buns (zesty swine, chewy dough) and a mouth-watering fried chicken-led ensemble featuring crunchy bird, lusty sausage gravy and tangy orange jam.

A trio of Andouille “corn dogs” could double as a meal. The gourmet twist on county fair food wraps savory Cajun sausage and creamy kin to gouda in a soft and sweet cocoon.

Scallop salad is gorgeous but deadly. The seared bivalve is placed in a bed of shaved fennel and dotted with bright orange briny fish roe; what you can’t see is the searing chili oil drizzled atop everything. But you’ll taste it with every breathtaking inhalation.

A pork chop sandwich arrives flanked with fragrant baked beans and crispy house-made chips. The slow-cooked mass of sugary beans is bolstered by shredded pork and bourbon. The gut-busting sandwich tops a tender, lightly breaded chop with caramelized onions, melted fontal (mellowing) and piquant aioli.

Ingwell appears to be genuinely pleased that food sales have continued creeping up since opening day — “We knew that this would grow organically,” he suggested — but stressed that management always anticipated that booze would be the No. 1 driver.

“At the end of the day, we’re a bar,” he said.

But folks have already begun clamoring for additional dining options. And management is determined to give the people what they want.

“We’ve been hearing dessert, yes,” he said of the rising chorus of those craving something sweet at the end of the evening. “We should be offering some sort of sweet item very regularly by the end of the month,” Ingwell projected.

He said Sunday brunch should follow shortly thereafter (tentative rollout is May25). And Fleming is developing more audacious creations, including a fonduta featuring stuffed gnocchi with rabbit carnitas poised to debut May 15.

Still, Fleming believes the ultimate goal is to preserve that “nice warm feeling” of walking into your neighborhood pub. “We didn’t want to lose that bar identity,” he said of the abiding mission.

So far, so great.

Food Court is an ongoing series of semi-regular spot checks of new and evolving eateries with ties to Capitol Hill.

Barrel 613 Pennsylvania Ave. SE; 202-543-3622; barreldc.com.

Average entree: under $12 ($). Open for dinner and late-night dining daily.