Mitt Romney had a binder full of women. Heater Allen brewer Lisa Allen has a binder full of beers.

"During the winter months," Lisa Allen says, "we have time to play with styles you don't normally brew."

And so each winter, the McMinnville brewer goes to the binder for new toys. At the World Brewing Congress years back, she'd picked up what she calls an "ultimate almanac of world beer recipes," handed out by 137-year-old German malthouse Weyermann, that was chock-a-block with lesser-known historical brew styles.

Using the recipes as baselines, Allen then rejiggers them according to her tastes.

She wasn't very familiar with roggenbier before finding it in the binder—she'd had one at Buoy in Astoria.

Roggenbier is, essentially, a rye-malt take on hefeweizen, a style Heater Allen already makes as beautifully as anyone in the state. Its Isarweizen hefe was one of our top 10 beers of 2014. It was also the first Oregon-made hefeweizen to even resemble—let alone rival—the Franziskaners, Weihenstephaners and Paulaners I'd spent a year drinking in the gardens of Munich.

But it's rare that a brewery wants to work with rye. And it's rare that even a German would make a roggenbier.

"Rye is such a pain to brew with," Allen says. "It doesn't have a husk. Both wheat and barley have a husk surrounding the sugars. So [the rye] gets mushy. It's harder to brew."

The gooey, sticky mash might clog up the filters, or refuse to flow.

But in Allen's roggenbier, those deeper, spicy rye flavors—30 percent rye, along with 70 percent Pilsner barley malts—also offer richness to complement those clove and banana notes in the traditional German wheat beer. It's a wintertime take on hefe that washes with warm and rounded subtlety across the palate—causing me to actually make an embarrassing, involuntary moaning noise on my first sip at Belmont Station.

"I was really happy the way that it tasted," Allen says. "I wanted to get that banana-bread aroma—and I wanted more spice on the flavor that you get a lot from rye beers."

It had the rye spice right out of the tanks. But that rich warmth has developed over the past month or so, she says, as the beer sat in kegs and the banana flavors bloomed from yeast.

Allen says it didn't sell much during the first weeks after she brewed it in December—and then suddenly everyone ordered it all at once, after word got around.

The 15-barrel batch of beer is sold out already at her McMinnville brewery—but as this guide appears, it will still be making its way around taps in Portland.

People have liked it so much, Allen says she'll probably throw the roggenbier back in the rotation after the next Isarweizen. But she's already looking into other beers in that binder.

"One of those we've talked about is a beer called sahti," she says. "It uses juniper as well as rye."

But the style she's looking at most could almost be third in the series after her Isarweizen and roggenbier: a dampfbier, German for "steam beer," made in the deep Bavarian forests along Germany's southeastern border.

"It uses the same yeast—wheat-beer yeast—but it's brewed with 100 percent barley," Allen says. "Somebody told us about it, and we looked it up in the binder."