It's holiday party season, and what's a holiday party without a little spike in the punch? Even better, a little beer in the pie?

Surly Brewing Co. is selling three pies through the end of the year, and each makes beer a primary ingredient.

• The Witch's Tower Pumpkin Pie features Witch's Tower, a beer Surly describes as "reminiscent of mint chocolate with a tingly, clean spiciness." ($25)

• Darkness Pecan Pie uses Darkness, Surly's hop-heavy Russian Imperial Stout, with flavors of chocolate, coffee, cherry, raisin and toffee. ($24)

• The Cynic Caramel Apple Pie incorporates Cynic, which has "notes of citrus and black pepper, with a dry, tingly finish." ($24)

Surly's pastry chef, Joanna Biessener, has long incorporated beer into her desserts; there's currently a Darkness Tiramisu available in the upstairs pizza place. But the pies are a new thing.

"We were in the process of making the tiramisu, and were like, 'Hey, Darkness is really flavorful and has a lot of the same notes that are in a pecan pie, so let's give that a try,' " Biessener said. "It turned out really awesome."

She took the idea and ran with it, coming up with the other two pies.

"The maltiness of the Cynic, it adds a body and a flavor you don't usually get from an apple pie," she said. "The Witch's Tower has a lot of cardamom notes to it, so it works really well with pumpkin pie spices."

But baking with beer isn't as easy as it sounds. Though the alcohol is mostly cooked off, the carbonation leaves behind some textural changes, making desserts lighter and fluffier than usual. Then, there's the moisture.

"There's as much beer as we can put in there, so they're definitely a bit more moist than people are used to," Biessener explained. "The pumpkin pie has a mousse-y texture to it because of the beer. It adds an extra oomph."

Pies are on sale through Dec. 31 online at shop.surlybrewing.com and can be picked up at Surly (520 Malcolm Av. SE., Mpls., 763-999-4040) with 48 hours' notice.