We hesitate even to guess how pumpkin and beer first came together. Whatever the origins of this union, however, it's better than you might imagine. Picture a pint of pumpkin pie, and you won't be too far off the mark. With a bright orange color, a distinct but not-too-pumpkiny nose, and a palate smacking of nutmeg, clove, and cinnamon, pumpkin ale has fast become a fall classic around these parts.

Truthfully, I've never been too fond of spicy or fruity brews (pumpkin is a fruit, dummy). But I'd be lying if I said I didn't like this one. It's not hard to understand why Cambridge Common recently went through three of its four kegs of Post Road Pumpkin Ale in less than a week, and why Boston Beer Works' Pumpkinhead Ale recently supplanted the ever-popular blueberry ale as its number-one seller. And it's no surprise that other breweries are in on the act. Cambridge Brewing Company makes the Great Pumpkin Ale; Watch City Brewing Company in Waltham brews one called, simply enough, Pumpkin Ale; and Coors-owned Blue Moon makes a nationally distributed brew called, uh, Blue Moon Pumpkin Ale that should be available in selected packies.

"It's a great fall beer," says Jodi Andrews, head brewer at Boston Beer Works. "It gets you in the mood for the cool weather. It's kind of a difficult one to drink when it's really warm." Of course, BBW's sister brewpub, Salem Beer Works, makes pumpkin ale all year (in Salem, every day is Halloween, right?) and it's consistently popular. For most of us, however, pumpkin ale is strictly an autumn drink. And with the work involved -- adding baked pumpkin to the kettle as soon as the brew comes to a boil, then adding vanilla extract and spices with the first and third hops additions -- it's no wonder that it's usually produced only from September through Thanksgiving.

But don't think the brewers don't love slaving over a hot vat in these cooler months. "The fall and winter are when we really have the ability to do our bigger (read: higher alcohol content) specialty beers," says Andrews. "We have the time -- we're not pressed because of the Red Sox and the need to brew the staples to keep everyone happy. This is when all the brewers' favorite beers come out. Now's the time when it's fun being a brewer."

To say nothing of being a beer drinker.

Pumpkin ale is available at: Boston Beer Works, 61 Brookline Avenue, Boston, (617) 536-2337. Watch City Brewing Company, 256 Moody Street, Waltham, (781) 647-4000. Cambridge Brewing Company, One Kendall Square, Cambridge, (617) 494-1994. Cambridge Common, 1667 Mass Ave, Cambridge, (617) 547-1228 University Wine Shop, 991 Mass Ave (between Harvard and Central Squares), (617) 547-3111; 1739 Mass Ave (between Harvard and Porter Squares), (617) 547-4258.