The maple tree outside my office window is glowing with a brilliant blaze orange. Garden centers and parking lots are still piled high with bright orange pumpkins. Coffee shops are hawking pumpkin spice lattes, and pumpkin beers are on store shelves.

Like the pumpkin spice latte, pumpkin beers are a divisive drink. Some view them as abominations; others can't get enough. Those who hate them can take solace in the fact that their season is short. October through early November is the window. Those who love them had better move quickly, as the window will soon close.

Pumpkin beers are nothing new. For early New World colonists, imported barley was expensive. They used pumpkin and squash as a supplemental sugar source to make their beer. The first Thanksgiving is said to have included ales made with pumpkin.

California brewpub owner Bill Owens is said to have made the first modern pumpkin beer in the mid-1980s as a gimmick. Not wanting to waste a giant gourd he had grown in his backyard, he brought it to the brewpub — Buffalo Bill's Brewery — roasted it, and added it to a spiced amber ale. It was an immediate hit with patrons, so Owens decided to bottle it, making Buffalo Bill's Pumpkin Ale the country's first commercially distributed pumpkin ale.

Pumpkin ales rely primarily on spices to communicate the effect. Cinnamon, allspice, nutmeg, ginger and clove are nearly universal among them. Most do include some amount of pumpkin or squash, though its flavor impact is actually minimal. A few forgo its use altogether, leaving it all to the spice.

Pumpkin ales used to be fairly straightforward. Most were spiced amber ales leaning heavily to graham cracker and caramel malt, with very little hop presence. Pumpkin pie spice was the star. Together with the malt, the spices gave these beers a distinctly pumpkin pie-like character. There were a few pumpkin porters or stouts that conjured pie with a cup of coffee.

These days, brewers are mixing it up a bit. The ambers and stouts are still around. But they are joined by pale coffee beers and hazy IPAs.

Pumking Imperial Pumpkin Ale from New York's Southern Tier Brewing Co. is the old school king of pumpkin beers. It once sold out of stores almost as quickly as it was put on the shelf. The frenzy has waned, but it's still a delicious beer. Vanilla and spice lead the way; nutmeg and ginger are most prominent. The ginger verges on spicy heat, cinnamon adds a subtle warmth and the malt is all crust-like graham cracker and caramel. At 8.6% alcohol, Pumking is rich, but not heavy.

With Warlock, New York's Southern Tier brings the Pumking treatment to an imperial stout. Hazelnuts, chocolate and caramel lead the way, with subtler tones of vanilla and butterscotch adding depth. The ginger and nutmeg spicing is gentle, and a high note of orange adds a pleasant counterpoint. This would be a great beer to drink with s'mores.

Night Owl Pumpkin Ale from Elysian Brewing Co. in Seattle is another one that follows the old model. It smells and tastes just like pumpkin pie. All of the spices are there — ginger, nutmeg, cinnamon, clove and allspice. The sweetness of butternut squash creates a full, creamy filling. A bit of crust-like, biscuity malt completes the picture. Crust, pumpkin and spice all linger in a long, satisfying finish.

Locally, Dangerous Man Brewing Company's Imperial Pumpkin Ale is a rich and warming fireside sipper. Pumpkin pie spices are present here, but more subdued than with many other pumpkin ales. The driver is creamy caramel and graham cracker malt. The interesting addition of Belgian candi sugar — a kind of caramelized sugar syrup — brings intriguing notes of dark fruits, like dates.

With Pumpkin Sombrero, the East Coast brewing company Clown Shoes has created an alcoholic, pumpkin spice mocha latte. Dark chocolate is in the forefront, but well balanced with dark-roast coffee flavors from the stout's roasted malts. Nutmeg, cinnamon and ginger are most prominent from the spice mix, making for a perfect Mexican mocha latte. Add squash-like sweetness and the picture is complete — a pumpkin spice latte lover's dream.

Colorado's Left Hand Brewing Co. tosses its hat into the pumpkin latte ring with Pumpkin Spice Latte Nitro. This has the amber glow of a traditional pumpkin ale, but the roasted flavor of coffee comes through loud and clear. Pumpkin pie spices play a close second, with ginger giving an especially potent bite. Toasted malts provide a sweet caramel base. Lactose and oats combine with the nitro carbonation for a smooth and creamy texture. All the elements are there, but in the end, they don't quite come together, leaving behind a muddled impression.

I would never have thought of a pumpkin IPA. But upon further contemplation, it's clear that those pie spices are natural partners for citrus. That makes them worthy partners for citrusy American hop varieties.

With the first sip of New Belgium's Voodoo Ranger Atomic Pumpkin Ale, ginger and a kick of habanero heat dominate. Keep sipping and the underlying IPA reveals itself. The result is a well-balanced melding of piquant spice and orange citrus hops. Habanero asserts itself, lingering in the back of the throat, but never goes over the top. The impression is one of particularly strong ginger. The IPA's malt base gives some balancing sweetness.

Hazy IPA is all the rage now, so of course there is a hazy pumpkin IPA. I'm not a fan of hazy IPA, but California brewery 21st Amendment's Pumpkin Haze IPA is surprisingly tasty. It presents a balanced blend of orange, tangerine, cinnamon and nutmeg. A hint of ginger spice gives it some snap. Touches of vanilla and graham round out the corners and soften the already moderate bitterness.

Michael Agnew is a certified cicerone (beer-world version of sommelier) and owner of A Perfect Pint. He conducts private and corporate beer tasting events in the Twin Cities, and can be reached at michael@aperfectpint.net.