PORTLAND, Maine ( MainStreet) -- Pumpkin beer is growing into a patch full of competition and a sophisticated seasonal beer for discerning beer drinkers.Since Shipyard Brewing of Portland, Maine, introduced its Pumpkinhead pumpkin ale to the masses 10 years ago, production has grown from fewer than 2,100 barrels in 2002 to 19,000, Shipyard's co-founder and master brewer Alan Pugsley says. During that decade, enough craft brewers have poured out their take on pumpkin ales and pumpkin stouts to attract the attention of their bigger brewing brethren. Anheuser-Busch InBev ( BUD) weighed in with its Michelob Jack's Pumpkin Spice Ale in 2005, MolsonCoors ( TAP) topped off its Blue Moon series with Harvest Moon ale in 2006 (and rebranded it as Harvest Pumpkin Ale this year) and even big craft brewer Boston Beer ( SAM) just added Samuel Adams Harvest Pumpkin Ale to its selection in 2010. Even as the market crowds and brewers' pumpkin vines tangle, there's still enough demand to force Shipyard to extend Shipyard's August-through-October release season to Thanksgiving and to increase production to an estimated 30,000 barrels -- or more than 413,000 cases. "We thought we just about maxed the deal last year when we sold 19,000 barrels of Pumpkinhead," Pugsley says. "That was all in a compressed time frame in August, September and October, but somewhere along the line it caught the imagination with the flavor or the headless horseman on the package." Pumpkin ale is nothing new in the craft brewing world, but its popularity has taken a while to ferment. Dogfish Head Brewery in Milton, Del., traces the roots of its popular Punkin' Ale back to 1994, when founder Sam Calagione took his spiced pumpkin homebrew to Delaware's Punkin Chunkin festival six months before Dogfish Head opened for business. At an event where slingshots, catapults and air cannon launch pumpkins through the air for more than 4,000 feet, the beer recipe contest judges were impressed enough to unwittingly make it one of Dogfish Head's first beers. "They were all 'Pumpkin and beer?' and we were all 'Yep' and they were all 'First place, we love it,'" says Dogfish Head's Calagione in the brewery's beer bio video. "Soon after that, we opened in 1995 and this became a staple -- we started brewing in the fall of 1995 and we've brewed it every fall since."