(Dogfish Head Craft Brewery)

That’s the concept behind Midas Touch (made with Muscat grapes) and Chateau Jiahu (flavored with hawthorn fruit), two of the ancient ales that Calagione has reconstructed at his Dogfish Head Craft Brewery in Milton, Del. It’s also the motivation behind Noble Rot, Dogfish’s newest release.

Noble Rot is a beer made with wine grapes. That in itself isn’t new. What is noteworthy is that the grapes and the grain each contribute about half of the fermentable sugars. More precisely, 49.5 percent of the sugars come from white wine grapes and 50.5 percent from barley and wheat. This is an equal partnership.

What’s also worth noting is the types of grapes used: viognier and pinot gris grapes from Alexandria Nicole Cellars in Prosser, Wash. The viognier grapes have been infected with a benign fungus called botrytis (or “noble rot”) that dries up the grapes, concentrating the sugars in the fruit. The pinot gris grapes have had their sweetness intensified by a technique called “dropping fruit,” which involves cutting off clusters of grapes and letting them drop to the ground. The idea is that the vine can suck up only so many nutrients to nourish the grapes and by thinning the fruit, the vintner increases the sweetness of what remains.

Calagione has produced a strong (9 percent alcohol by volume), pale gold beverage with an aroma of ripe grapes and an initial sweetness that dries out to a spicy, saison-like finish, thanks to a fermentation with a Belgian yeast strain. Noble Rot is highly effervescent. I drank half a bottle, then hammered the cap back on to save the remainder for the following evening. Usually, this results in a fairly flat beer. But my sample was almost as sparkling the second night as the first.

Given that beer and wine are taxed and regulated differently, did Calagione get any flack from alcohol regulatory authorities? “The only challenge was that the TTB [Tax and Trade Bureau] wanted a better description of at what point we added the grapes,” noted Calagione. For the record, the botrytis-infected must (the unfermented grape juice) is added after the boil, and the pinot gris juice post-fermentation, primarily for extra aroma.

Calagione estimated that he made about 4,400 cases of Noble Rot and expected it to linger on shelves until May. He anticipated prices of $12-13 for a 750-mililiter bottle. That will scarcely recoup his costs, he added. “I paid $62,000 alone to transport a tanker truck of temperature-controlled grape must from coast to coast,” he noted.

Aside from the joy of experimentation, Calagione confesses that he had another reason for producing this beer: “We always wanted to see if a beer with the word ‘rot’ in the name would actually sell.”

Beer calendar: Although there is no real down time for beer events, the calendar does tend to crowd up after Valentine’s Day. Tonight, Great Lakes Brewing Co. marks its debut in northern Virginia with launch parties at both Rustico locations in Arlington and Alexandria. Meet the brewers and snag a souvenir glass. The same evening, beer director Greg Engert will tap 15 “Revolutionary Ales from the Dark Side” at ChurchKey, many never before seen in Washington.

On Tuesday, Belga Cafe on Capitol Hill hosts a “Sour Valentine” beer dinner featuring the tart red ales Rodenbach and Rodenbach Grand Cru as well as the lambics Boon Framboise and Boon Kriek, among other selections. Price for the three-course meal is $49 per person.

On Wednesday, to celebrate the leap year, Jackson 20 in Alexandria will price Starr Hill drafts and pork tots at 29 cents from 11 a.m. until closing. That same evening, R.F.D. Washington will hold the second of its annual strong ale tastings, featuring multiple breweries and their beers. Among those penciled in is the Cabinet Artisanal Brewhouse in Alexandria, subject of Daniel Fromson’s recent column. Thus far, brewer Terry Hawbaker has been shipping all his output north to the Farmers’ Cabinet restaurant in Philadelphia, and this will be a rare opportunity to sample his beer locally.