Crafting a bigger niche: call it the mouse that roared. Or the little engine that could. It's the American craft beer industry, and it keeps chugging along each year at a healthy clip.

At its start over three decades ago, craft beer initially the province of a few rebels fed up with the lack of beer diversity in the U.S. They borrowed heavily from the brewing traditions of England to start their micros and brewpubs. By the Eighties, when these small brewing companies were generating excitement, money moved in looking for quick returns. The proliferation of labels and inconsistent quality confused the public, and a predictable exodus followed.

By the Nineties, the craft beer niche was made up of companies that understood both good beer and good business: a strong, mature niche, catering to a public that now takes wide beer choice and quality for granted. Even drinkers who generally stick to Bud, Miller or Coors know about pale ales, porters and wheat beers and many enjoy buying them from time to time.

But if the craft beer field has grown up, it hasn't grown stagnant. Its best brewers are creating new beers to keep their old fans excited, while they win over drinkers from other beverages. And this last success has caught the attention of major brewers, for solid financial reasons.

Craft beer's numbers are impressive: while mainstream beer has been nearly stagnant for several years, the craft beer segment has been growing steadily, with 11.7% growth last year, or a three-year growth rate of 29.5%, according to the Brewers Association (the trade association for small brewers).

Granted, the craft beer category is growing on a very small base (under 5% of all beer consumed in this country), while the major companies are losing a small amount on a very big base (everything else we drink except imports). But growth like this creates ripples through the whole industry.

Paul Gatza, director of the Brewers Association, explained: "The effect is actually bigger than the numbers that you see. As people shift from the major domestic lagers, they are drinking less in terms of volume and more in terms of quality. So, while the shift in terms of volume is small, the shift is greater in dollar sales, as well as enjoyment. If people are having two craft beers instead of three of four major domestic beers, then the shift is one and a half to two times the volume shift."

Today's craft beer leaders now have two audiences: their peers in the craft world, who welcome their innovation, and the major brewing companies, which have been adopting and adapting craft styles to pitch to a larger, more mainstream audience.

So, what keeps the 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, and some may make the transition to the mass market.

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 further east to the other great ale-brewing nation, Belgium.

While most of Europe lost its beer style diversity under waves of indifferent lager, Belgian brewers cherished local eccentricities. Sour beer, strong beer, fruited beer, aged beer, wild-fermented beer, monastic beer and spiced beer--all of these styles and brewing techniques were destined to win American converts. In the nineties, 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, exclusively Belgian-themed breweries are few, but most brewpubs and many micros now include at least one Belgian-style beer in their line-up. These beers include some of the most sophisticated American craft beers, many cork-finished and bearing a hefty price tag.

The success of these beers in attracting beer enthusiasts, press attention and prestige has led to the occasional edgy exchange with genuine Belgian brewers over the beers' authenticity. The conciliatory response of some Belgo-American brewers is to call their creations "Belgian-inspired."

They have, in fact, created some uniquely American beverages, sometimes combining the spiced notes of Belgian yeast, the funkiness of wild fermentation and unusual aging and blending processes in ways the mother country might not recognize.

Take Allagash Brewery's 11th Anniversary Ale. It combines Belgian malt and American hops, fermented with champagne yeast, to produce aromas reminiscent of red licorice and nutmeg, and flavors with date and fig notes. With alcohol content at a near-wine level of 9 percent, this ale pushes the boundaries of what drinkers expect from a beer.

By contrast, Belgian adaptations by larger breweries are relatively tame. Only one Belgian style has moved beyond the ranks of the small brewers and gone mainstream: the wit or white beer style is unfiltered, light, and citrusy, and spiced with orange peel and coriander. Regional or heritage breweries, customarily a little more conservative than smaller micros, have picked up the style: the Matt Brewery, for example, includes Belgian White Ale in its Saranac Summer Collection.

Leinenkugel (SABMiller) chose the wit for its new Sunset Wheat. Pete Marino, Miller Brewing spokesman, described Miller's association with Leinenkugel, the Wisconsin family-run brewery, as part of a response to "trading up" by the beer drinking public, which he sees Meting the growth in craft beer. "We're playing in that space," he said. "With Leinenkugel, we're rolling out Sunset Wheat nationally to great success--wheat beers are a hot part of the craft beer world right now."

Anheuser-Busch brewed a wit, Spring Heat Spiced Wheat, for spring release as part of its Specialty Seasonal Draught Program (a program that, itself, shows the influence of the craft movement). And the style 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--ample reason for modern brewers to switch 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 Belgian brewers to create deliberately sour and acidic brews.

At Russian River Brewing Co. in Santa Rosa, CA, founder Vinnie Cilurzo dedicates a separate room to aging beer in wood. Cilurzo, who came to brewing from a career in winemaking, varies the base beer, the barrel source, and the microorganisms to create complex, labor-intensive beers. Temptation is a blonde ale aged for twelve months in used Chardonnay barrels with a wild yeast known for its "barnyard" qualities. A second beer, Supplication, is a brown ale aged in used Pinot Noir barrels with sour cherries, wild yeast, and selected strains of bacteria that sour the beer.

"I love brewing these beers," says Cilurzo "because there is an unknown, especially with what we do using Brettanomyces and microorganisms--also known as 'bugs and critters.' There is a long production time on the barrel beers, a minimum of one year and sometimes as long as two or two and a half: that is as long and in some cases longer than a wine's production time. Patience is the key."

Dark beers can respond beautifully to wood aging, too. Bourbon County Stout from Chicago's Goose Island Brewery nearly overpowers the drinker with flavors of chocolate, coffee, toffee and strong alcohol. Brewer Greg Hall created the beer to celebrate the brewpub's one-thousandth batch, and drinkers await its appearance every year.

Other sweetish styles have appeared in wood-aged versions, such as the bourbon barrel-aged doppelbock from Sprecher Brewing Co. in Glendale, WI; a barley wine from Kuhnhenn Brewing Co., Warren, MI and a porter from Tyranena Brewing Co. in Lake Mills, WI.

These indulgent beers are easy to like: rich dessert drinks that replace dessert as easily as they accompany it. It's not surprising that Anheuser Busch tried its hand at Michelob Celebrate Vanilla Oak, which is aged not in but on bourbon barrel oak--meaning flavored oak chips. So far, no other majors have followed suit.

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. The Great American Beer Festival in Denver--the country's oldest and largest--has added the style to its list of competitive categories, a sign that the style has attracted a number of adherents, though no guarantee of its staying power.

The first double or imperial IPA appeared in the early 1990s, credited to the prolific Vinnie Cilurzo of Russian River Brewery, then working at a brewery in southern California. The style slowly gathered supporters, and today there are dozens of examples.

One of the best known is 90 Minute Imperial IPA from Dogfish Head Craft Brewery in Delaware. Founder Sam Calagione is one of microbrewing's great showmen, whose sought-after beers always come attached to good stories. In this case, Calagione converted an electronic game table into a jiggling platform that could shake a small dose of hops into the boiling beer wort every minute for 90 minutes. The process has now been automated, but still takes advantage of the full range of hop bitterness and aroma that come from early and late additions of the herb. The brewery also produces a gentler 60 Minute IPA, and a massive 120 Minute, with a hefty 20% alcohol.

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, CO. These beers are positioned as aggressive palate bruisers.

While high bitterness is very attractive to many craft beer drinkers, lack of bitterness is cultivated as an asset in mainstream beers, with "no aftertaste" touted in advertising. Some mainstream beers may become slightly hoppier, but the imperial IPA isn't destined to cross over.

Authenticity and Flavor

As craft styles become more widely accepted, brewers large and small are looking at an overlapping market--people who have not converted to craft brands but are attracted to a wider range of styles.

To deal in cliches, somewhere between Joe Sixpack, who will never drink anything but mainstream beer, and the Beer Geek, who will only drink the hoppiest IPAs, is a consumer who is available to be wooed by both camps.

The big brewing companies--no fools, and staffed with the best technical talent available--have seen that the drinking public is open to the more challenging flavors that specialty brewers have provided, and they are all making forays into the specialty sector. The Big Three--Anheuser-Busch, Miller and Coors--are perfectly capable of delivering many of the flavors that consumers are looking for in their beer.

The craft beer "badge" can be valuable in luring new drinkers. The craft beer community is rightly alarmed by the possibility that the big companies will take advantage of a receptive but still-naive market, and flood the market with lower-cost craft-beer wannabees. Anheuser-Busch launched more new beers last year than any year in its history, over half of them aimed at the craft-drinking market.

So the next step was predictable: the craft brewing community is drawing up stricter definitions that confer or withhold craft beer status. If the beer revolution has been about flavor, look for small brewers to shift the argument now to authenticity. New rules about what constitutes a "craft beer" have little to do with the beer. Instead, they focus on the size of the brewery, its ownership structure, and the ingredients it uses.

At the same time, given the popularity of the sector, many craft brewers are looking to expand their distribution, and some are doing so by building relationships with big brewers--thus jeopardizing their own craft beer status in attempts to reach new audiences. Craft brewer Goose Island in Chicago, for example, will soon enjoy the distribution channels of Anheuser-Busch, as Widmer Brothers and Redhook already do. Goose Island produces examples of all the cutting edge trends described earlier: will their distribution agreement mean they are no longer "craft"?

In the past three decades, what was extreme in beer has moved to the middle. Samuel Adams' remarkable Boston Lager is now available in convenience stores. Anchor Brewery's Liberty Ale, a startling bitter beer when it was introduced in 1976, is now regarded as only moderately hopped. Neither beer is less delicious for being widely accepted.

But this highlights the conundrum of being a revolutionary: how to balance the desire to change all of society and still maintain the rebel's outsider status. The still-small craft beer sector has changed the entire beer industry--which was one of its goals. But craft beer will only remain vibrant as long as its leading brewers keep innovating on the edges.

BREWMASTERS'

Specials

One of the advantages of small-scale brewing is flexibility. This is most evident in a brewpub setting, where a single experimental batch of beer can be brewed, served to customers, and the recipe adopted, adjusted or abandoned with no loss of investment in packaging or marketing. Constantly changing beer lists and seasonal specialties are a welcome part of the small brewers' landscape.

Recently, more craft breweries have offered one-off beers that shift the emphasis from the beer to the artistry of the brewer. A "brewmaster's selection" or "brewer's choice" beer is an invitation to the drinker to think of the beer in personal terms as the creation of one man or woman. It has also given established brewers a chance to flex their creative muscles.

Daniel Carey, the award-winning owner and brewer at New Glarus Brewing Co. in New Glarus, WI, oversees construction of a new facility erected just to satisfy demand for his beers in his home state. But along with their flagship Spotted Cow beer, and the Wisconsin Belgian Red flavored with cherries, the brewery has a series called "Unplugged"--one-off beers labeled with Carey's own image and packaged in four-packs.

"I'm doing lots of weird beers," explains Carey. "A lot of it is aged in oak and I'm doing a lot of work with different yeast strains.

"This is not something I say lightly, because I try to be a humble person," he continues, "but I don't think there's a brewery anywhere else in the world that makes a Brettanomyces sour brown ale aged in oak, a strong aromatic IPA, and an American light lager all in the same week. In our own little world of Wisconsin, I think people think we're a lot of fun."

The "brewer's choice" concept allows larger craft breweries to introduce some freshness into an established line-up of styles. Shipyard Brewing Co. in Portland, ME uses the concept to give "the brewers an opportunity to develop creative new recipes to bring to the marketplace."

Some craft breweries have taken the personalization of brewing even farther by launching collaborative efforts that combine the talents of master brewers from two breweries, sometimes from two different countries. That's the case with the latest in Harpoon Brewery's Hundred Barrel series, its brewer's choice program.

Following a visit to Denmark by a team from the brewery, Harpoon brought fourth-generation brewer John Juul Rasmussen from his family farmhouse brewery, the Refsvindinge Brewery, to brew a Danish-style buck beer with Harpoon's brewer, Al Marzi.

Some years ago, Colorado's New Belgium Brewing Co. created Transatlantique Kriek ("Kriek" means cherry in Flemish), by blending a cherry-infused Iambic prepared by master Belgian Iambic brewer Frank Boon with a beer created by Peter Bouckaert, New Belgium's head brewer. And Garrett Oliver, master brewer at Brooklyn Brewery, has embarked on cooperative brewing projects with brewers in both England and Germany.

The goal here is not only to showcase the personal role of the brewer, but to consciously blend brewing traditions.

CRAFT BEER

In Cans

Ironically, one of the boldest recent steps in craft brewing has been to adopt a technology formerly limited to the biggest companies: putting beer in cans. Since so much of craft brewing has grown up in opposition to mass brewing, the idea of craft beer in a can seemed to fly in the face of craft brewing's central image.

Canned beer is associated with mass marketed beer, but not because beer in a can is of lesser quality: in fact, any tainting of the flavor from contact with metal has long been solved, and cans protect beer from light damage as effectively as bottles. But canning lines are among the most expensive pieces of brewery equipment, far beyond the reach of small brewers, and this difference in economic might has been translated into a difference in perceived quality.

However, Cask Brewing Systems, a Canadian firm, developed the first manual canning system affordable to small brewpubs and micros. A number of small companies decided to crush the can's declasse image. The most successful has been Oskar Blues Brewing Co. in Lyons, CO. It launched Dales Pale Ale in 2002, an unapologetically hoppy, strong (6% ABV) craft beer exclusively in cans. In one competition after another, Dale's bested well-regarded pale ales from other craft companies, countering the notion that good craft flavor couldn't come in a can.

Oskar Blues followed their pale ale with even craftier beers: Old Chub, a strong Scottish ale and Gordon, the first double IPA in a can. Craft brewers are realizing that if the prejudice against cans can be overcome, their beers can be made available at beaches, on golf courses, in aircraft--anyplace where glass bottles are too heavy or dangerous.

Julie Johnson Bradford is the editor of All About Beer Magazine.