On a normal day, thirsty revelers easily drain two kegs of Guinness at Boston's Black Rose tavern. Come St. Patrick's Day -- an official holiday in Bean Town -- and they'll plow thorough 55 kegs.

"It's pretty crazy over there," says Keenan Langlois, corporate chef for The Black Rose and the seven other restaurants in Boston's Glynn Hospitality Group. "People start early and spend all day there."

And these days, not all of that Guinness is going down parched gullets. With what he says is the largest Guinness account in Massachusetts, Langlois figured it was time to use it as an ingredient in food too. His Black Rose burger stacks prime beef with Irish bacon, shredded cabbage and Guinness-spiked ketchup. And he's not alone.

Chefs have long known that the hearty Irish stout, brewed in Dublin since 1759, can add complexity to stews, soups, dips and even desserts. They use its bitterness and toasty malt flavor to offset rich, fatty meats, and echo its notes of chocolate and coffee in cakes and ice cream. Its creaminess offers a great platform for cheese, they say, especially Irish blues.

"It has a rich spectrum of uses," says Paul Hartley, author of "Guinness: An Official Celebration of 250 Remarkable Years" (Hamlyn, 2009). "It's this rounded velvety feel and it fuses with all the right things. Like oysters and blue cheese and chocolate. From time to time, I marinate chicken in Guinness and lime and grill it. It brings all that to life."

Hartley's idea of the perfect St. Patrick's Day starts with Guinness-marinated Irish bacon, moves onto crepes with Guinness-poached mushrooms for lunch, and ends with a dinner of Irish "beef cobbler," that is, Guinness-braised beef served with scones.

Pastry chef Alice Medrich would add dessert. Medrich has laced Guinness through chocolate cupcakes, reduced it to a syrupy essence, concocted creamy, egg-yolk-based ice cream from it and made Guinness granita to scrape over vanilla ice cream. She sometimes uses it for the contrast of bitter and sweet, but also exploits its notes of coffee and chocolate to layer flavors. Exhibit No. 1? Her stout float with chocolate ice cream, chocolate syrup and Kahlua.

"It's building the flavors," says Medrich, author most recently of "Sinfully Easy Delicious Desserts" (Artisan, 2012). "There's a lot of chocolate-coffee-malty things going on in the Guinness. The Kahlua picks up on the coffee notes in the Guinness. So everything's working together."

Carbonation makes beer a natural friend of salty, fatty cheese, says Janet Fletcher, author of the upcoming "Cheese & Beer" (Andrews McMeel, April 2013). Stout, in particular, she says, offers elements of caramel that complement varieties such as Gouda, and creaminess that boosts triple-cream cheeses.

That creaminess also makes it a good match for mild blue cheeses, Fletcher says, such as Ireland's soft, supple Cashel Blue. And though she says she prefers hoppier beers with cheddar, she admires the historic pairing.

"It's been the cornerstone of many a pub lunch for centuries," she says. "There's the pleasure of knowing you're having a classic."

The possibilities are seemingly endless. In its "100 ways to cook." column, the food blog Endless Simmer showcased recipes such as onion soup with a Guinness-based broth, mashed potatoes with Guinness gravy and even Guinness lasagna.

"In recent years people are cooking a lot more creatively with Guinness than they used to," says the site's editor, Brendan Spiegel, pointing to the lasagna -- which incorporated Guinness into a salsa verde topping -- as the funkiest recipe. "I don't know what it wouldn't go with. It's definitely a wintery flavor, which is why it works for St. Patrick's Day. You wouldn't mix it with fruit or something you're trying to make light and summery. It's for hearty cuisine."

Not everyone is enamored of Guinness. "It's just not very interesting," Peter Begg, head of food development for Jamie Oliver Ltd. and a fan of craft beers, writes in an email. "It's OK to drink with oysters and to cook with a beef stew, but that's about it really."

Perhaps it's a question of familiarity breeding comfort rather than contempt. Author Hartley loves it for its iconic status. And its longevity.

"Every time I go to a food exhibition and I see three- or four-thousand new products, the next year when I come back there will only be a few left," he says. "But the Guinness will still be there."

Caramelized Onion and Guinness Dip

Servings: 16. Start to finish: 30 minutes. Recipe by Alison Ladman.

     1     tablespoon olive oil

     2     large sweet onions, diced

     1    cup cold Guinness

     1/2     teaspoon salt

     1/2     teaspoon ground black pepper

     1/4     teaspoon cayenne

     1     pound extra-sharp cheddar cheese (preferably Irish), cubed

     Crackers, chips or bread, to serve

HEAT the olive oil in a large skillet over medium.

ADD the onions and cook, stirring occasionally, until browned and caramelized, about 20 minutes. If the onions begin to char before they caramelize, add a tablespoon or 2 of water. Set the onions aside and allow to cool.

COMBINE the cooled onions a food processor with the Guinness, salt, pepper, cayenne and cheddar. Pulse until combined and smooth. Serve with crackers, chips or bread. Also makes a great spread for a roast beef sandwich.

Nutrition information: Per serving: 130 calories, 90 calories from fat (69 percent of total calories), 10 grams fat (5 grams saturated, 0 grams trans fats), 30 milligrams cholesterol, 3 grams carbohydrate, 0 grams fiber, 1 gram sugar, 7 grams protein, 240 milligrams sodium.

Irish Chop Suey

Servings: 6. Start to finish: 30 minutes. Recipe by Alison Ladman.

     6    12-ounce bottles Guinness

     1     pound package wide egg noodles

     1 1/2     pounds 90 percent lean ground beef

     1     large yellow onion, chopped

     2     cloves garlic, minced

     3     tablespoons all-purpose flour

     1     tablespoon brown mustard

     2     tablespoons Worcestershire sauce

     1     teaspoon dried thyme

     Salt and ground black pepper

     3     green onions, chopped (white and green parts)

BRING the Guinness to a boil in a large stockpot over medium-high heat.

ADD the egg noodles and cook until al dente, according to package directions. Drain the noodles, but reserve 3 cups of the liquid (add water if needed to have 3 cups). Set both aside.

COMBINE, meanwhile, in a large, deep skillet over medium-high the ground beef, onion and garlic. Sauté until browned and cooked through, about 10 minutes.

ADD the flour and stir to coat. Stir in the mustard, Worcestershire sauce, thyme and reserved Guinness. Cook for 5 minutes, or until the sauce has thickened. Season with salt and black pepper. Stir in the egg noodles and serve topped with green onions.

Nutrition information: Per serving: 680 calories, 130 calories from fat (19 percent of total calories), 15 grams fat (6 grams saturated, 1 gram trans fats), 135 milligrams cholesterol, 74 grams carbohydrate, 3 grams fiber, 4 grams sugar, 36 grams protein, 270 milligrams sodium.