Coffee Beer. bold, bracing, rich and roasty

is a delicious addition to the craft brewing scene

Tröegs JavaHead Stout, 7.5% ABV | Made with a mix of bright Kenyan beans and a bit of creamy, bodybuilding oats, JavaHead swims with bittersweet dark chocolate flavors—no surprise from a brewery in cocoa-capital Hershey, Pa.

AleSmith Speedway Stout, 12% ABV | More like coffee liqueur than beer: Take a snifter of this one on the porch and watch the snowfall. The alcohol burn and tannic coffee bite satisfy those who take their daily jolt hot, black and syrupy-strong.

Lagunitas Cappuccino Stout, 8.8% ABV | Irreverent NorCal stalwart Lagunitas is infamous for its big, brash beers, and this stout is no exception: fruity and thick, sweet like the crema off a perfectly-pulled espresso shot, with espresso's dense finish of licorice and vanilla.

Kona Pipeline Porter, 5.3% ABV | From Hawaii's largest brewery, made with coffee grown down the Kona Coast, this mellow porter opens with a big, dark-roasted aroma and tastes nutty and spiced: chocolate with a dash of chicory, a handful of hazelnuts.

Ballast Point Victory at Sea Imperial Porter, 10% ABV | Mixed with 100 gallons of cold-brewed coffee from San Diego neighbor Caffé Calabria, this porter calls to mind sweet Thai iced coffee. Refreshing chilled, spicy as it warms.

IT MAKES SENSE , in a twisted way. Two drinks, chemically opposite but spiritually simpatico, both ensconced in craft connoisseurship and the values that implies: small batches, strong flavors, conscientious sourcing and sophisticated technique. An upper, a downer, one hot, one cold, and yet: Why shouldn't coffee and beer get along?

John Trogner thought they should. With his brother Chris, Mr. Trogner runs Tröegs Brewing Company, in Hershey, Pa. He's also a coffee fanatic. "For me," he said, "it was taking my favorite beverage in the morning and my favorite beverage at night, and blending them." Which, at first, is exactly what he did. "We pulled espresso shots and dumped them in beer—foam everywhere, it was a mess," he said. Plus, the flavors didn't quite work. Turns out it isn't as simple as coffee and beer, mixed.

The challenge is balance. The darkly roasted grains that give porters and stouts their rich color also contribute coffee-like flavors on their own; adding beans can overdo it. Bad coffee beers taste like bad coffee—over-extracted, stale, burned—whereas the rich, toasted malts in Tröegs JavaHead Stout play in counterpoint to citrusy Kenyan beans steeped in the beer pre-fermentation, in an apparatus similar to a giant French press.

Tröegs mixes in an additional dose of cold-brewed coffee, but it's more about flavor than buzz. Coffee beers have barely any caffeine. Four Loko, the infamous neon alcoholic energy drink, is a hefty 12% ABV, and had as much jolt as a full cup of joe until 2010—when the manufacturer removed its caffeine after the FDA declared the drink a "public health concern." JavaHead, in contrast, has less caffeine than a cup of decaf.

Instead, coffee beers energize with their espresso-like mix of rich sweetness and bracing acidity. As third-wave coffee roasters tend toward lighter roasts, we might see coffee beers doing the same. "A really dry coffee IPA would be awesome," Mr. Trogner said. But for now, they're mostly dark, and perfect for this time of year, when a blustery beer both smooth and crisp, soothing and brash feels a little wrong, and just right.