Craft beer chugs along

Call it The Mouse That Roared. Or The Little Engine That Could. It's American craft beer, and it keeps chugging along each year at a healthier clip than bigger players. Every spring, America's craft brewers meet to assess their small corner of the huge domestic beer industry, learn from one another and drink one another's outstanding beers. Last month at their conference in Austin, the mood was giddy: The craft beer segment has been growing steadily, with a three-year growth rate of nearly 30 percent, and this year's growth at 12 percent.

Numbers like these create ripples through the whole industry. Everyone has one eye on what small brewers are making.

So, what keeps the beer revolution fresh? Several trends have the craft world talking and tasting. Most got off to modest starts some years ago, but these have gathered enough momentum to spread. Some may make the transition to the mass market, and all have examples on local shelves.

Anything Belgian: England may have inspired the first generation of American craft brewers, but once English pale ales and India pale ales became established as the flagship brands of microbreweries and brewpubs, restless brewers looked farther east to the other great ale-brewing nation, Belgium.

Sour beer, strong beer, fruited beer, aged beer, wild-fermented beer, monastic beer and spiced beer -- all of these Belgian traditions have won American converts. In the '90s, a handful of craft brewers were bold enough to open breweries dedicated entirely to Belgian-style beers, including Ommegang in New York, New Belgium in Colorado, and Allagash in Maine.

Today, most brewpubs and many micros now include at least one Belgian-style beer in their lineup. The most popular is the wit or white beer style, which is unfiltered, light, and citrusy, and spiced with orange peel and coriander. The beer has long been a success story for Blue Moon, winning over drinkers who are unaware that the style is Belgian or that the brewer is Coors.

Beer on the wood: Despite the fact that we measure beer in barrels and dispense it from kegs, very little beer comes into contact anymore with wood, the material from which these containers were originally constructed. Wood is a living material that can impart its own flavors to beer -- which is why modern brewers switched from wood to stainless steel. But that very quality has inspired a small number of craft brewers to resurrect wood containers as a source of added complexity.

Wood can flavor beer in at least three ways. Oak, the most commonly used wood, can introduce notes of vanilla and buttered toast to beer, as it does to wine. If the barrel has been used previously to age another beverage -- bourbon, wine or sherry -- the residual notes will pass to the beer. Finally, wooden barrels can harbor a range of microorganisms that can affect the beer, a nightmare in most brewing traditions, but one that has been harnessed by some brewers to create deliberately sour and acidic brews.

Imperial Everything--Especially IPA: American craft brewers' infatuation with hops -- the herb that lends both bitterness and aroma to beer -- established India pale ale as a brewpub staple. But, in our typical bigger-is-better tradition, some brewers steadily increased hop levels until many IPAs were, by the parameters of the style, excessively bitter, overly alcoholic and out of balance. The solution? Declare a new style.

Accordingly, the Double or Imperial IPA is by explicit definition extremely bitter and highly alcoholic. It borrows its "imperial" moniker from the Russian Imperial stout style that was created in the 19th century with more alcohol and hops to protect it during export to Russia, where it was very popular with the royal court.

Pilsners and porters have also been "imperialized" recently, but the super-sized India pale ale is by far the most popular category. Many sought-after Imperial IPAs wear their attitude in their names: Ruination IPA from Stone Brewing Co. in San Diego; Hercules Double IPA from Denver's Great Divide Brewing Co., Maharaja Imperial IPA by Avery Brewing in Boulder, Colo. These beers are positioned as aggressive palate-bruisers.

All these cutting-edge beers are appearing on retail shelves, although few have been adopted yet by North Carolina micros. Instead, look to our brewpubs, with their faster turnover and flexibility, to experiment on the fringes.