Some time ago, Willie Wonka’s famous chocolate factory developed a prototype beverage called Fizzy Lifting Drinks. Unfortunately, due to some snafus in the plant (some sort of contamination of the machinery, according to industry gossip), the drink never made it onto the shelves.

Fortunately, the folks at London’s Young Brewery have taken it upon themselves to devise their own fizzy chocolate concoction — one that, at five percent ABV, gives more than a little lift. Their Luxury Double Chocolate Stout is just the thing for a chilly winter evening; almost tantamount to boozy cocoa, it should be sipped from a mug.

A member of the sweeter, British genus instead of the dry, hopped-up Irish variety, Young’s stout comes by the " double " part of its appellation because, in addition to being brewed, as many other chocolate stouts are, with chocolate malt and with barley that’s been heated almost to the point of burning (which unleashes a complex palate of sweetish, burnished flavors), this brew adds a second helping of chocolate during the brewing process — yes, actual melted candy bars. The result, redolent of chocolate, is sweet but not too sweet, as well as muted and malty.

The " luxury " obviously derives from the drink’s obscenely rich, satiny sheen. A thick, frothy concoction that swishes over the tongue like a milkshake with a kick, it’s a drink worthy of its highfalutin moniker. Enjoy it. Just take care not to become an alcochocoholic.

Young’s Luxury Double Chocolate Stout is available for $8.30 for four 440-milliliter (14.9-ounce) cans at Downtown Wine & Spirits, 225 Elm Street, in Somerville. Call (617) 625-7777.