Things are changing rapidly on Capitol Hill. The Lil Pub is gone. Remington's closes on Monday. The Pour House disappears at the end of the month. And on Friday night, Barrel, a Southern bourbon bar, officially replaces the old 18th Amendment at 613 Pennsylvania Ave. SE.

Barrel's bar is longer than the 18th Amendment's, and run the length of the bar room. (Photo by Fritz Hahn/The Washington Post)

Matt Weiss, a partner in the new venture and the owner of the Hill's Union Pub and 201 Bar, says the inspiration came from places he visited with friends in Charleston, SC. "I fell in love with what they're doing there," he explains, pointing to "inventive cocktails, bars making their own ingredients, the great food … but also the laidback nature of the places. They're very welcoming."

Barrel Dozens of bourbons, rye whiskeys, Tennessee whiskeys, Scotches and Japanese whiskeys are offered on Barrel's menu. (Photo by Fritz Hahn/The Washington Post)

Weiss kept the idea in the back of his mind. Last year, he approached Mike Schuster and Mark Mernard, the owners of the 18th Amendment and the Pour House, about bringing the concept to the 18th Amendment building. The men had known each other for years: Weiss was a partner in Politiki, which became the Pour House. Weiss and Politiki co-founder Joe Englert sold the Pour House business to Schuster and Mernard years ago, but retained an interest in the building itself. The 18th Amendment closed last July after seven years, and Schuster and Mernard "felt like it had run its course," Weiss says. They moved forward with what they call " a Southern bourbon bar, but more Capitol Hill and neighborhoody."

Where 18th Amendment sported huge mirrors and chrome, Barrel is stripped down to brick walls and exposed boards, with tables arranged in the new bay windows, and a wide wooden bar that snakes the length of the building.

Despite the 16 taps of local and California craft beers, the focus is the shelves of whiskey: 50 bourbons, 20 ryes and around 20 Scotches and Tennessee whiskeys. The prices are average: You'll pay $9 for a glass of Four Roses Small Batch, $10 for the E.H. Taylor Small Batch or $12 for Noah's Mill.

Flip over the "Brown Water" menu and you'll find a special "Reserve" list with some familiar names: Pappy Van Winkle 23-year ($40 per ounce), the new Parker's Promise of Hope from Heaven Hill ($35 per ounce) and the Elijah Craig 21 year ($30 per ounce). One that made me scratch my head, though: Black Maple Hill, which hasn't been that hard to find lately, is $20 per ounce.

Barrel Bartenders will age cocktails for weeks in the "Lab" portion of the bar. (Photo by Fritz Hahn/The Washington Post)

In the back of the bar room is "The Lab," where bartenders experiment with aging cocktails in small barrels. Bulleit and Peychauds bitters, for example, were aged together for three to four weeks for use in the barrel-aged sazerac. (The absinthe is added before it hits your glass and doesn't spend time in the wood.) The plan is that the barrels will "cascade" with repeated uses, so that eventually a rum will wind up in a barrel that previously held bourbon and hopefully pick up some of whiskey flavors.

Chef Garret Fleming (formerly of the Pig and Lincoln) is in the kitchen, making fried chicken with sausage gravy and biscuits, fried pork chop sandwiches topped with gruyere, large bowls of mac and cheese, and a salad of morels, ramps and chanterelles in beurre blanc. Prices are mostly in the $10-$15 range. Brunch and happy hour menus are on the way, though not finalized.

The most interesting space in the building, though, is the low-ceilinged basement bar called Elixir. The cozy hideaway sports rough wooden tables, a jumbled collection of old cupboards and sideboards and a few stray full-sized barrels. Most of the light comes from "the dispensary," a glass-doored vault of Pappy Van Winkle, Elijah Craig and the other pricey bourbons. Weiss plans to host beer dinners, pop-up dining experiences and other events down here, but if there's nothing scheduled, it will follow the same hours as upstairs. One thing to remember: There's a separate menu downstairs with fewer aged cocktails and half as many beers, just to keep you on your toes.

Upcoming events include two tap takeovers, with DC Brau on April 22 and Devils Backbone on May 8.

Barrel, 613 Pennsylvania Ave. SE. 202-543-3622.

The low-ceilinged Elixir Bar feels like it could have been a speakeasy in a former life. (Photo by Fritz Hahn/The Washington Post)

Barrel's exterior got almost as much of a makeover as the interior, with new windows a surface stripped down to brick. (Photo by Fritz Hahn/The Washington Post)

Barrel's dining area runs parallel to the main bar. (Photo by Fritz Hahn/The Washington Post)