GORHAM, Maine — Inside Sebago Brewing Co.’s warehouse, towering walls of purple-and-white cans signal the release of the season’s favorite brew, Slick Nick.

“Our customers love it. They love it when it comes out,” says co-founder Kai Adams, taking a slug of his long winter ale.

The days of the longest nights are here and with that come hearty, robust ales in all their diversity. Dark days brightened by crisp notes turn many (even avowed wine and eggnog fans) to crack open a holiday ale under the tree.

In the decades since Harpoon’s pioneering Winter Warmer was introduced, New England craft brewers have turned the notion of a cinnamon- and nutmeg-infused seasonal on its head.

“Five or six years ago I would’ve said a holiday or winter beer is an old ale, typically malty, sweet, a little alcoholic, between 6 and 9 percent alcohol,” says Adams.

In the craft beer age, one size no longer fits all.

“The style guidelines have changed. We’ve stuck to the guns of being a malty, strong and robust beer, but we’ve changed up the specialty malts, so that there is a more complex caramel and crystal malt, giving the beer more complexity,” he says.

For 15 years, Geary’s Winter Ale has sated beer fans from November through the first week in March with a medium-bodied, chestnut ale. This year, owner David Geary tweaked his recipe with a new ingredient: blackstrap molasses. Added during fermentation, the rich syrup gives the Scottish ale a “caramel-like aroma. A mouth feel that’s smooth and creamy with hints of chocolate and molasses,” says Geary.

Maine’s seminal brewer experimented on his new pilot brewing system and retooled a classic.

“The lightbulb goes off over your head and you say, ‘You know what?’” says Geary.

Most brewers agree a winter ale has more alcohol (though Geary’s is a modest 5.5, while Funky Bow’s Santa’s Sack clocks in at 10.5 percent alcohol by volume).

To Greg Sansone, head brewer at Gritty McDuff’s, a winter ale is designed to make you feel “a little more jolly. It’s stronger, sweeter, something that will warm you up.”

Unchanged for more than 20 years, Gritty’s Christmas Ale holds the baseline on holiday beer in Maine.

The Portland-based brewer’s reddish extra special bitter is made with English-style yeast. Like a sourdough starter, it is replenished year after year.

To Sansone, a holiday ale is of the same ilk as a German Oktoberfest or summer ale.

“There is a scarcity aspect to the beer … ‘drink it while you can,’” he says.

At smaller, newer outfits such as Funky Bow Brewery and Beer Co. in Lyman, holiday ales go as fast as discounted cashmere on Black Friday.

Santa’s Sack, a red ale aged for a year in Woodford Reserve bourbon barrels, was released on Dec. 12 and there are just 20 bottles left. The limited, small run of the 750-milliliter bottles (which retail for $18) are akin to a collector’s item.

“People look forward to it. It’s an anniversary thing, available every holiday,” says Funky Bow’s Abraham Lorrain. “We have fun brewing it. It’s bigger with higher alcohol content.”

Bourbon-soaked wood imparts a toasty, vanilla, festive flavor.

But what makes a winter beer wintry?

“It’s whatever you want it to be, really. There is no such style as a winter ale, it tends to be richer in body, to go with cooler weather, more flavorful,” says Portland’s craft beer grandaddy D.L. Geary.

What will you leave out for Saint Nick?

Kathleen Pierce

A lifelong journalist with a deep curiosity for what's next. Interested in food, culture, trends and the thrill of a good scoop. BDN features reporter based in Portland since 2013.