DON'T ASK for a pint of pumpkin beer at South Street's Brauhaus Schmitz. One of Philly's few bastions of Bavarian beer purity doesn't serve the spice stuff because the Germans already have a perfectly fine autumn beer, thank you.

It's Oktoberfestbier, also known as Marzen, that copper-colored beauty, rich in malt with a smooth body for endless guzzling.

"Personally, I'm OK with pumpkin beer," Brauhaus Schmitz owner Doug Hager said. "But as a card-carrying German beer snob, we kind of laugh at it."

He's in the minority these days. American beer drinkers have gone gaga for gourds, turning pumpkin beer into the biggest-selling seasonal style of the year.

"I mean, just look at what Charlie [Collazo] has pulled together," Hager said, referring to the owner of the Institute Bar (12th and Green streets, Spring Garden). "He's got, what? A hundred different pumpkins lined up for his [Oct. 4] Pumpkin Beer Festival this year?

"You'd be hard-pressed to find 30 Marzens in Philly."

How can this be?

Oktoberfestbier is one of the world's longest-standing beer styles, a harvest lager brewed for Munich's massive 200-year-old beer festival. Hundreds of millions of liters have been hoisted over the years. It defines the fall beer-drinking season.

And now it's being replaced by an upstart cinnamon-laced squash?

It's as if Pat's suddenly declared itself King of Tacos.

Blame it on our collective A.D.D., which has us constantly in search of the next, new thing. Oktoberfestbier? Isn't that what our grandfathers drank?

Blame it on American craft brewers, too. They're answering the marketplace by tweaking recipes to produce ever-bolder-tasting ale. This is the age of peanut butter porter and über hops, not old-school lager.

Don't fret - there's still a decent selection of Oktoberfest-style beers out there. Sierra Nevada, for example, just added one to its fine Fall Variety Pack.

Here's a sixpack of my favorites:

_ Victory Festbier (Downingtown): A slight smokiness gives this smooth, lightly sweet lager added complexity.

_ Sly Fox Oktoberfest (Pottstown): A superb take on the style that's tailgate-ready in a can.

_ Stoudt's Oktober Fest (Adamstown): An exceptionally clean, crisp version from the region's original German-oriented craft brewer.

_ Great Lakes Oktoberfest (Cleveland): Traditionalists will find this one a bit hoppier and sweeter than the typical Marzen.

_ Ayinger Oktober Fest-Marzen (Aying, Germany): Bready and smooth, a true malt treat.

_ Weissenohe Monk's Fest (Weissenohe, Germany): From a traditional monastery brewery in Franconia; look for it in flip-top half-liter bottles.

Oktoberfestbier was made to be guzzled from a liter - full, mouth-foaming gulps draining down your throat to the happy beat of an oompah band. Grab your lederhosen and start flexing your elbow, because Saturday is the first day of Munich's Oktoberfest, and Philly is home to a pair of its own authentic Bavarian street fests.

In Fishtown, Frankford Hall (with Fette Sau, its neighboring barbecue joint) will close down Frankford Avenue, between Girard Avenue and Shackamaxon Street, from noon to 10 p.m. Carnival games, raffles and plenty of food will complement the beer tents, where you'll find Marzens beer from Sly Fox, Samuel Adams, Great Lakes, Victory, Paulaner and more.

Meanwhile, Brauhaus Schmitz will shut down the 700 block of South Street for its own lively festival, from noon to 8 p.m. Look for classic festbier from Ayinger, Weihenstephaner and Weissenohe, among others.

Both festivals are free admission and kid-friendly.

Want to learn more about Marzens?

Next week, I'll host an Oktoberfest-themed beer-and-sausage pairing at the Loft at Iron Abbey (680 Easton Road, Horsham). I'll focus on three varieties to examine the style's history and flavor. Tix $30, 215-956-9600.

And, no, I'm not wearing my lederhosen.

"Joe Sixpack" is written by Don Russell. For more on the beer scene, sign up for his weekly email update at joesixpack.net. Email: joesixpack@phillynews.com.