Despite this lofty perch, however, not that many U.S. craft breweries make a similar Belgian-style quadrupel -- typically dark red or brown in color and loaded with malts and sugar that give it a high alcohol content and rich, sweet flavor.

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"They are expensive to make because of all the ingredients," says Walt Chleva, a brewer at Dry Dock Brewing in Aurora. "And it's a style that isn't really well-known."

But that could be changing, as there are currently four bottled quads and two draft-only quads -- all made by Colorado brewers -- now floating around Denver (see the full list below).

One of those is Chleva's creation, the cheekily-named Waltvleteren 12, which he first brewed in 2011; he's since adjusted the recipe to make it smoother. "I've always liked the bigger, maltier beers," says Chleva, who has been brewing at Dry Dock since 2009. "I've made an English barleywine and an Irish red. So when I had the opportunity to make one of my own, I wanted to go big."

Chleva modeled his beer off of several of the best-known Belgian quads, like St. Bernardus Abt 12, La Trappe and, of course, Westvleteren 12, which he got to try after buying a few bottles online (for more than $25 a pop). "I did some research and learned that they only use pale and pilsner malts and caramelized sugar," he says. So Chleva used similar malts, along with dark syrup and candied sugar, and a Belgian yeast strain similar to one used by the Trappist breweries.

Chleva has gotten good feedback on the beer, and is hoping to enter Waltvleteren 12 into the competition at the Great American Beer Festival -- "that is every brewers' dream," Chleva says -- and maybe even bottle it as a Dry Dock seasonal at some point.