The months of winter call out for strong, fortifying beers — imperial stouts, barleywines, strong Belgian ales — big warming brews to stave off the chill. One style fits the bill that remains largely unexplored is Baltic porter. Stylistically, Baltic porter fits into a niche between traditional porter and imperial stout, with a dash of German schwarzbier thrown in for good measure.

The style showcases porter-like flavors with the smoothness of a lager and a higher gravity and alcohol, with rich malts and dark fruit flavors. Baltic porter could also be referred to as imperial porter, though excessive hoppiness or roasted flavors are inappropriate.

As the name implies, the style originated in countries surrounding the Baltic Sea, such as Poland, Russia and Finland. During the 18th and 19th centuries, England shipped porter all over the world, and the Baltic states developed a preference for the higher gravity versions of these beers. Stouts evolved from porters, and in particular a strong stout was commissioned by empress Catherine the Great of Russia in the 1780s, which became known as “imperial” stout in association with the royal court.

Brewers in those countries began brewing their own versions of strong porters and stouts.

One hallmark of their processes was cold conditioning the beers, otherwise known as lagering, even when using traditional ale yeast; the use of lager yeast followed among many breweries as lager beers became more established.

After World War II, the Iron Curtain effectively cut off these breweries and Baltic porters from the west. As a result, the style was all but forgotten until the end of the Cold War in 1991. Today, Baltic porter is still a niche style but more and more craft breweries are taking it on.

Locally, Spider City Brewing Company offers its own interpretation with Black Lava Sea Salt Baltic Porter as part of its regular lineup. I recently picked up a four-pack of cans of the brew and reached out to owner and brewer Melanie Betti to find out more about it.

“The inspiration behind this recipe came from me and my sister, Michele (who is also an owner of Spider City Brewing), and our travels through the Baltics,” she said via email. “When we are abroad it is our goal to see the topography of an area and experience the local beer and culture of the region where we travel.

“In our travels through Poland, Lithuania and Belarus we were able to sample many Baltic Porters,” she said. “It is interesting to note that Poland’s national beer style is Baltic Porter.” Betti pointed out that in fact Poland just celebrated its Baltic Porter Day on Jan. 16.

As the name indicates, Black Lava is brewed with sea salt, which gets added during the whirlpool (post boil) and in the bright tank during conditioning. “The amount I use is just enough to enhance the flavor of the roasted malts,” said Betti. “Think chocolate complimented with sea salt!”

At 5.9% alcohol by volume, it’s lower in strength than many other examples which are often quite high (sometimes approaching 10%). I found a pleasant cold brewed coffee aroma with dark bread crust and a touch of cookie dough in the maltiness, with just a hint of roast that has a soft chocolate roundness.

In the flavor, some roasted malt is tempered with semi-sweet dark chocolate and malty caramel. Despite the dark brown color it doesn’t taste too roasty or dark and has a light nuttiness and mellow toasted grains. It has a touch of chewiness in the mouthfeel and a malty, coffee-like finish. It’s pleasantly chocolatey and easy drinking.

Several other breweries are also currently offering interpretations of Baltic porter; Sunriver Brewing Company recently tapped Finnish Flash, brewed as a lager with a bit of rye to 8.5% alcohol by volume; and 10 Barrel Brewing Company just released Celebrity Crush, a barrel-aged imperial porter inspired by the Baltic style and brewed in collaboration with Portland’s Breakside Brewery.

With two months of winter still ahead of us, Spider City’s Black Lava is a good starting point to exploring the style and delving into these strong dark brews of Eastern Europe.

1. Slippery Slope Winter Ale — Cascade Lakes Brewing

2. Inversion IPA — Deschutes Brewery

3. Czech Pilsner — Buoy Beer

4. Waist Deep Winter Ale — Bend Brewing

5. Acai Lemonade Cider — Avid Cider