Winter has us in its icy grip. Snow coats the ground, and the days are as frigid as the nights are long. For the hardy few who love the cold, abundant winter sports beckon them outdoors. The rest of us hunker down indoors, anxiously awaiting spring's thaw.

Whichever type you are, the season calls for big, warming beers — the type sipped slowly from a snifter, ideally in front of a crackling fire. Russian imperial stout is the perfect choice. As the regal name implies, it just might be the king of beers. Rich, roasty and boldly flavored, it fills the mouth and the heart with the comforting warmth of a woolen blanket.

Like every other stout style, Russian imperial stout began as porter. During the late 18th century, the heyday of porter brewing in London, porters were brewed to various strengths. The heftiest of them were called "stout porters." Porter brewers sold these strong, dusky ales as "double brown stout," "imperial porter" and "imperial double brown stout," and a plethora of other terms meant to imply great strength.

The "imperial" designation likely referred to the strong export trade that the London brewers had with the Baltic States and Russia, including the Russian imperial court of the empress Catherine the Great. But the term "Russian" doesn't appear to have been attached to imperial stout until the early 20th century.

Stories have been told that the superstrong stout was created to prevent the beer from freezing en route to Russia. This is almost certainly not true. Strong porters were being brewed for the home market as well. And it would have required extremely cold temperatures for the high-test beer to freeze. The truth, both then and now, is that strong beers were brewed because that's what customers demanded.

Modern imperial stouts are full-bodied with a velvety texture. Built on roasted grains, they showcase flavors like bitter chocolate, strong coffee and even slightly burnt. Bitterness can be high, but the massive load of malt leaves a perception of sweetness in some examples. Underlying notes of caramel, molasses, bread or toast are not uncommon. Additional complexity comes from fermentation-derived flavors of dark fruits like raisins, plums and prunes.

Imperial stouts also are prime candidates to be aged in used spirit barrels. Barrel-aged versions take on additional caramel, vanilla and whiskey dimensions from the barrel's previous contents.

Bad Weather Company’s Calamity is a very full-bodied stout. (Provided/The Minnesota Star Tribune)

The juggernaut of local imperial stouts is undoubtedly Surly Darkness. This is the beer that once inspired hundreds of fans to line up overnight to snag a few bottles on Surly's annual Darkness Day. The hype has subsided, but the beer is as good as ever.

Coming in at 12% alcohol, the 2022 iteration is full-bodied and rich — almost sticky. Flavors of deep, dark fudge mingle with contrasting notes of resinous hops. It's those hops that make Darkness so delicious. Bitterness from both hops and roasted grain is high but offset by significant residual sugar.

The Minneapolis brewery also offers Darkness in three barrel-aged variants. Lumberjack Breakfast Darkness features notes of maple, coffee, cinnamon and vanilla beans. Ginger Snap Darkness features a ginger bite mellowed by cocoa and vanilla. Raspberry Chocolate Torte is aged in rye whiskey barrels with raspberry, cocoa and vanilla.

Calamity from Bad Weather Brewing Co. in St. Paul is a very full-bodied stout — rich and creamy with a velvety texture. It's slightly sweet up front, but the sweetness soon gives way to hop and roast bitterness that lingers long after swallowing. The bitterness subsides some as it warms, making room for smooth, bittersweet chocolate. Strong coffee and dark molasses flavors complete the picture.

Aged in Heaven Hill bourbon barrels, Barrel Aged Stout from Lakes & Legends Brewing Co. in Minneapolis is a complex, layered sipper. Like Calamity, it's bitter up front and in the finish, with a sweeter center. Bourbon has a caramel and vanilla presence, but still lets the stout's bittersweet chocolate roast take the lead. It's relatively low alcohol at just 8.6%, but it still warms on the way down.

At just 7.7% alcohol, Satin Solitude from Central Waters Brewing Co. in Amherst, Wis., is among the lightest examples available. Satin Solitude comes off like a strong brown ale, leaning more on Tootsie Roll-like chocolate and caramel than intensely roasty flavors. It's remarkably easy-drinking for the style.

Boulevard Brewing Co. in Kansas City has two imperial stouts on shelves now — one barrel-aged and one not. Dark Truth is the straight one. It's built on dry roastiness with coffee grounds and Oreo cookies taking precedence over caramel and toffee. A touch of burnt, roasted-barley bitterness gives this one a dry finish that lingers on coffee.

Boulevard's Whiskey Barrel Stout takes a similar dry-roasted base and sweetens it up with caramel, vanilla and whiskey flavors from aging in bourbon barrels. Warming alcohol is noticeable but doesn't cross the line into boozy. It's surprisingly fruity. Cherry notes combine with velvety chocolate and bourbon to leave the impression of a winter cocktail.

The "huge" in the name of Huge Arker from California's Anderson Valley Brewing Co. is appropriate. At 15.5% alcohol, it's a behemoth. Twelve months of aging in bourbon barrels yields a big, boozy and complex sipper that is surprisingly smooth for its heft. The barrel is a main player, with bourbon, caramel, vanilla and oak taking center stage. The caramel becomes more and more apparent as the beer warms. Notes of dark fruit, dark chocolate, honey and bread add layers of complexity.

Wake Up Dead Imperial Stout from Left Hand Brewing Co. in Colorado hits with intense and sharply bitter roasted malt character. Strong coffee and high-cocoa dark chocolate are the main drivers. The roast is tempered some by notes of blackstrap molasses and dark fruits. This is a dream beer for lovers of roasty stouts.

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.