Cold weather means time for imperial stout beer

January is a month to hibernate. The cold is bitter. The snow piles up. And while the daylight hours are gradually increasing, the process is oh, so slow. The long, dark nights become oppressive.

January is a month to curl up by the fireplace or under a blanket with a strong, warming drink in hand. A snifter full of hearty Russian imperial stout is just the thing. It's a beer as black as the seemingly endless night. The velvety texture is soothing on the tongue. With alcohol levels from 8 percent to as high as the brewer can push it, the beer brings a personal midwinter thaw.

Russian imperial stout isn't actually from Russia. The style originated in Great Britain as a strong beer intended for export to Russia and the Baltics. One brand was reportedly so popular with the Czarina Catherine and her imperial court that the brewer marketed the beer as "Russian Imperial Stout." The name stuck.

Locally, the granddaddy of imperial stout is arguably Surly's Darkness. It was once a beer that sold out within an hour or two of hitting store shelves, but increased production and the sheer glut of beers on the market have slowed the frenzy. I've seen bottles available throughout the Twin Cities.

Darkness is a big beer, but its off-dry finish, lingering roasted malt and assertive hop bitterness make it seem lighter than it is. Flavors and smells of semisweet chocolate and bitter coffee are complemented by a sturdy pine resin and citrus hop character that adds an almost refreshing element.

Many people like to cellar this beer like fine wine, anticipating positive changes from the effects of age and oxidation. But I say drink it now. The hop expression makes this beer stand out, and that will fade quickly. A bottle of Darkness won't ever be better later than it is right now.

Bell's Expedition Stout is a beer that would do well with some time in the cellar. This immensely complex beer is all about malt. The aroma hits your nose with a panoply of aromatics — molasses, licorice, dates and figs, bitter chocolate, caramel and sweet alcohol. The flavor is equally deep. Bittersweet chocolate flows across the tongue like silk. Molasses, coffee grounds, dried fruits and a host of other flavors come and go in waves. Expedition Stout is an intense beer to be savored slowly.

Stouts have long been brewer favorites for making flavored beers. The chocolate and coffee flavors of stout brilliantly complement vanilla, fruit, spices and even smoke. Imperial stout allows for such experimentation on a grand scale.

Xocoveza from Stone Brewing is an imperial stout modeled after Mexican hot chocolate. It's brewed with chocolate, coffee, pasilla peppers, vanilla, cinnamon and nutmeg. A kitchen-sink beer of this sort can be a muddled disaster. But this one works extraordinarily well, reminding us of its inspiration while still remaining beer.

There's a lot going on in Xocoveza. Just when you think one flavor has taken control, it cedes to another. Moderate sweetness up front gives way to cocoa and roast malt bitterness with a side of cinnamon/pepper spice. The capsaicin heat is low — just a tingle. It's more about pepper flavor than spice. The finish is off-dry with lingering chocolate and pepper.

FSB from Fair State Brewing Cooperative in Minneapolis is made with vanilla and orange zest. At nearly 14 percent alcohol, this is a monster of a beer. That booziness, coupled with an almost-syrupy sweetness and body, make this a slow sipper. While tasty, a small pour is really all you'll likely want.

Milk chocolate is the base flavor, with underlying notes of molasses and raisins. The vanilla is strong — almost overwhelming — adding to the impression of rich sweetness. The clarity of the orange zest in such an intensely flavored beer is surprising. It adds bright, refreshing high notes that offer some relief from the beer's cloying intensity.

Odell Brewing Co. ages Jolly Russian in rum barrels. At 13 percent alcohol, this is another beast of a beer. But full attenuation makes Jolly Russian less ponderous than Fair State's FSB. It drinks like a beer of much lesser strength — a fact that could make it dangerous.

The sharp and acrid characteristics of roasted malt are subdued. Dark fruits are the main event here — rum-soaked raisins, plums and tart cherries. It's all enveloped in a layer of bittersweet chocolate that grows more intense as the beer warms in the glass. A touch of dry roast in the finish accentuates the impression of dryness.

Lift Bridge Brewing Company's Silhouette is blended from beers aged in a variety of bourbon barrels, some for up to two years. It's full-bodied, with intense roasted malt sharpness. Bitter coffee and licorice are softened by notes of toffee. Barrel aging adds layers of whiskey, caramel and vanilla.

It's imperial stout season. These are only a very few of the great examples available for savoring right now. Get sipping!