Housed in a quiet shopping plaza in Aurora, Dry Dock Brewing Co. looks like any other craft brewery: Fourteen varieties of beer are on tap, awards are plastered on the wall, and bearded fans are always tossing back pints. Sitting on the corner of the bar, though, is a key to some of the most inventive brews in the Centennial State and to Dry Dock’s success: the firkin. Firkins, which are small kegs (only 10.8 gallons), are the perfect vessel for brewers to try out adventurous recipes and crazy combinations, such as roasted Hatch chile beer, wasabi rice ale, or coconut porter.

To create the one-of-a-kind firkin flavors, Dry Dock owner Kevin DeLange adds new ingredients during the last day of fermentation, so the beer finishes brewing while merging with the introduced flavors. “We started doing the firkin right when we opened [in 2005],” says DeLange. “It’s fun and lets you experiment. Now a lot of people come in every Friday, especially if it’s going to be a good batch or a really weird batch.” If the brewery hits on a strong mix, like the coconut porter, the mini-keg drains in just a few hours, leaving wistful customers gunning for the next round.

Other brewers are joining the grand experiment: Oskar Blues runs Firkin Fridays at its Tasty Weasel Tap Room in Longmont, and Golden City Brewery frequently hosts Firkin Thursdays. Golden City’s head brewer, Jeff Griffith, says that it allows the brewery a chance to give brand-new flavors a test run before they hit the shelves. “We think of the different styles to brew based on what we think people will like,” Griffith says. “So far the vanilla porter has been a huge hit—makes me think that a bigger batch may be in order.”

The Long Draw

Three spots to sample firkins—get there early, before the beer runs out.

Dry Dock Brewing Co.
When Fridays, starting at 3 p.m.
Favorite flavors Belgian Double IPA and Wasabi Rice Ale
15120 E. Hampden Ave., Aurora, 303-400-5606

Golden City Brewery
When Frequently, Thursdays, starting at 11:30 a.m.
Favorite flavors English Mild and Vanilla Porter
920 12th St., Golden, 303-279-8092

Oskar Blues’ Tasty Weasel Tap Room
When Fridays, starting at 5 p.m.
Favorite flavors Belgian Pale Ale and double dry-hopped Dale’s Pale Ale
1800 Pike Road, Unit B, Longmont, 303-776-1914