Mike Snider

USA TODAY

The great pumpkin beer invasion has begun — already.

Labor Day looms and pumpkin beers have overrun your supermarket and favorite beer boutiques. Fans of Oktoberfest brews will have to scour through a patch of pumpkin beers to find those other seasonal favorites.

That may be an exaggeration, but not much of one. Last year during the month of October, pumpkin beer outsold even India pale ale, the most favored year-round craft beer style, the Brewers Association says.

You could argue that pumpkin beers have boosted craft beer's continued ascension in the marketplace. Last year, craft beer sales rose about 20% to $14.3 billion, up from $11.9 billion in 2012, the association says. Meanwhile, overall beer sales were flat for 2013.

Fall seasonal craft beer releases saw a similar increase last year, up 15% from 2012 to $530 million, says Bart Watson, staff economist for the association. That figure covers all seasonals, including Oktoberfest beers and the first holiday arrivals, but "come October, pumpkin beer is the undisputed heavyweight champion of the seasonal world," he says.

So, competition for pumpkin beer sales has led to brewers getting their offerings into stores earlier. Dozens of pumpkin beers are hitting retailers. (Talk about getting a head start — there's even a few holiday seasonals out already.)

"They are more popular than ever, so you are going to see more of them, and thus they are going to be on the market when the brewers deem it's time to start thinking about fall," says Brewers Association Program Director Julia Herz.

Back in 2007, the association saw enough interest in pumpkin beer to create a separate subcategory for the style at the Great American Beer Festival, which the group operates. Seven beers were entered.

Then the category was expanded to "Field Beer," to include other harvested vegetables and plants, and attracted 91 entries, the majority of them pumpkin beers, Herz says. So this year, pumpkin, for the first time, gets a category all to itself.

""There's something very nostalgic and comforting to pumpkin beers, to me, above all other seasonals," she says.

One of the retail pumpkin beer originators, Dogfish Head Craft Brewery, began marketing its Punkin Ale in 1995 and it has become the Rehoboth Beach, Del.-based brewery's best-selling seasonal. It's being tapped at Dogfish Head's brewpubs this weekend and being shipped now to retailers.

Demand has "grown every single year that we have brewed it," says Sam Calagione, the brewery's founder and president, who expects that 2014 sales will surpass last year's by 28%.

And while he decries "the creep of seasonal beers that get released earlier and earlier," Calagione understands it. "Every year, distributors and retailers say, 'OK, who can get me a pumpkin beer first?'"

Pumpkin beer is a truly American beer style, he says, because it uses homegrown ingredients. "The Colonists would make beer out of whatever they could — corn, pumpkins and gourds were pretty early sources of fermentable sugars for our ale-loving ancestors," Calagione says. "I feel like we have a native pride in this style, and it's been awesome to watch all kinds of American brewers put their unique twist on it."

Traditionally, pumpkin ales have been dark orange-ish amber ales or brown ales — Punkin Ale is a brown ale made with pumpkin, organic brown sugar, cinnamon and allspice — but brewers are expanding the pumpkin possibilities.

One of the first pumpkin beers to hit the marketplace this year was Pumking from Southern Tier's Brewing Co. (available in bottles and on draft). Alongside it was the brewery's Warlock, an Imperial stout brewed with pumpkin that the Lakewood, N.Y., beermaker first sold last year (both have an alcohol by volume (ABV) level of 8.6%).

But other pumpkin beers, from coast to coast, were hot on the heels of Pumking and Warlock. Other early arrivals included:

— Alewerks Brewing Co. Pumpkin Ale (six-packs of 12-ounce bottles). This Williamsburg, Va., brewed beer, which carries a 7.3% alcohol level, greets you with a sweet aroma and a slightly salty taste, perhaps from the roasted pumpkin. Its uniqueness could make it a good choice for recent sour beer converts.

— Fermentation Without Representation Imperial Pumpkin Porter (22-ounce. bottles and draft). This limited release and recurring collaboration between Utah's Epic Brewing Co. and Washington's DC Brau Brewing Co., which also comes in at 8% alcohol, has a roasted malt aroma to match a cocoa-tinged taste.

— The Fear Imperial Pumpkin Ale (six-packs). The dark lord of Imperial pumpkin ales, the adventurous Frederick, Md., brewer has delivered a 9% deep-brown beer that offers a taste of nutmeg and hint of bitter chocolate along with the subtle earthy flavor.

— He Said Belgian-Style Tripel/He Said Baltic-Style Porter (12-ounce cans). San Francisco's 21st Amendment and Seattle's Elysian Brewing Co. collaborated on these offbeat beers. The strong, yeasty tripel employs tarragon and a root called galangal; the roasty porter, Vietnamese cinnamon and caraway seed.

— Schlafly Pumpkin Ale (available in six-packs and draft), a subtly spice-driven brew with notes of cinnamon and nutmeg, from The Saint Louis Brewery. At 8% alcohol, the ale stands out from other pumpkin ales in part because it is made with Polish Marynka hops.

— Shipyard Smashed Pumpkin (12-ounce and 22-ounce bottles), the stronger cousin of the Portland, Maine, brewery's Pumpkinhead, is a wheat ale in the lineup for 12 years (out in bottles and cans). This is a 9% heavyweight that works great as a dessert beer.

— Uinta Punk'n Harvest Pumpkin Ale (12-ounce bottles and cans). The spice-laden ale, which the Salt Lake City brewery released in August, isn't quite as heavy on the booze, coming in at 5%.

— Weyerbacher Imperial Pumpkin Ale (six-packs). Clove lovers will want a whiff of this 8% ale from the Easton, Pa., brewery. Also in the mix: cinnamon, nutmeg and cardamom.