Cold brew

The imperial stout famously had its birth in the 18th century after England began sending an amplified, higher-alcohol version of domestic stouts to Russia to sate the taste of Peter the Great, who had recently visited the British Isles and taken a liking to local beer styles. The altered formula for the popular black beer was a tactic meant to protect the stout, stored in barrels, from freezing and bursting during the open sea voyages into sub-Arctic latitudes.

It turns out another, but lesser-known, beer style was born through similar interactions between England and the countries surrounding the Baltic Sea. In this case, porter—thick, rich and jet-black, like stout—was brewed to higher strength before being exported to the Baltic states.

Over time, brewers in Scandinavia, Finland, Estonia and neighboring nations began making their own porters—but with a local twist. Instead of ale yeast, they used lager yeast to brew what were traditionally rich, roasty ales. Lagers and ales are the two basic and distinct categories of beer, each brewed with its own species (not strain, but species) of yeast. Ale yeast—Saccharomyces cerevisiae—ferments at warmer temperatures and converts sugar to alcohol rather rapidly, with primary fermentation of a batch taking about a week. Lager yeast— S. pastorianus—works best at lower temperatures, and it ferments more slowly. The Baltic region being cold, lager yeast was a popular brewing tool for the region’s beer makers, and many of them, though not all, began making dark black porters using the slow-fermenting culture.

The result is what we know today as the Baltic porter, perhaps the world’s most unlikely lager. The style—marginally popular, at best, today—is rich, thick, hearty, strong and toasty, not what you would expect of a stylistic cousin of the pilsner. It drinks like an imperial stout, really, but the attentive drinker will notice a subtle distinction—notably that Baltic porters carry a lighter, more delicate malt body than ale porters, thanks to the distinct esters released by lager yeasts.

At Fairfax’s Iron Springs Pub and Brewery, a Baltic porter, Forbidden Donut, was recently on tap. Brewer Christian Kazakoff made the beer using chocolate, but otherwise Forbidden Donut is true to the Baltic style, made using lager yeast. He says the same beer fermented with an ale yeast would be fruitier and fuller.

“With a lager yeast, it’s lighter, more crisp and delicate,” he said.

The beer had a vague Tootsie Roll flavor and a soft essence of chocolate when I tasted it at the brewpub in late November. I would recommend allowing the beer to warm a bit in the glass before drinking, especially on a chilly day, as I found it allowed the flavors and aromas to emerge.

The style is not exactly wildly popular among brewers, but Chico’s new Secret Trail Brewing Co. has a Lights Out Baltic porter in its portfolio, and you can find other breweries’ renditions at better beer shops. At BevMo, I’ve picked up Zywiec Porter and the Baltika 6. Each tastes like molasses, caramel, coffee and toasted bread. Allowed to warm to about 55 or 60 degrees, few beers are so warming and satisfying in December.