The Boston Beer Company is of course best known for its flagship Boston Lager, which, over the past two decades, has established itself as a tried-and-true staple beer if ever there was one. But owner Jim Koch is a restless sort, always looking to push the envelope, toying with esoteric beer styles that many casual drinkers may not have heard of.

"We make beers that I love," Koch says, over glasses of Samuel Adams Black Lager at his Jamaica Plain brewery. "Every beer that comes out of here is something that I think is a truly great beer. One of the things we’re always looking for is wonderful beers we can bring to the American beer drinker. And Black Lager is one of them."

The man speaks the truth. Also known as a schwarzbier, this is one lager that departs fairly drastically from common conceptions of the style. Whereas many lagers are light and dryly effervescent, this is deep, dark, and delicious, marked by a rich sweetness that’s never cloying and a gorgeous roasted character. With a provenance "primarily in East Germany, but a little bit in Bavaria," the beer "was developed in its current form probably in the early 1800s," Koch says. "That was before you had the paler malts that enabled pilsner beers to emerge in the mid-19th century. Before that, all beers were dark."

Indeed, the Black Lager is in many ways similar to an ale-style beer, like a dark and frothy porter. "Yes, it’s exactly like a porter," Koch says, holding a glass of the stuff up to the light. "It’s not a complete black hole, like a stout, but under normal conditions it looks that way. It’s sort of an intimidating color."

Much more striking than its dark beauty, though, is the Black Lager’s olfactory and savory allure. "In the aroma, there’s a lot of malt. You don’t get a burnt smell from it, you get a malty sweetness. Toffee, caramel," says Koch. "I get roasted notes, but not burnt notes. There’s a drop of sweetness, nicely balanced by coffee flavors, almost like cappuccino." It’s all accented by the beer’s luscious consistency, a rich, almost viscous quality that’s not at all heavy or filling. "It’s an all-malt beer," Koch explains. "It’s got a lot of protein in it. And there are some compounds formed in the roasting of the malt that actually contribute to head retention."

As much as Koch is in love with this style (and well he should be; I sure am), he’s wary that some folks — people who may be accustomed to more staid Sam Adams styles — might shy away from it. "It’s a scary beer," he says. "It’s uncompromisingly dark, and it scares a lot of people off. It’s an intimidating style. A lot of beer drinkers are afraid of the dark."

They shouldn’t be. That’s just silly.

Available in six-packs and as part of the Sam Adams Brewmaster’s Collection 12-packs at most area liquor stores.