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 – they’ll plow thorough 55 kegs.

“It’s pretty crazy over there,” said Keenan Langlois, corporate chef for the tavern and the seven other restaurants in Boston’s Glynn Hospitality Group. “People start early and spend all day there.”

But these days not all of that Guinness is going down parched gullets. With what he said 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.

He’s not alone.

Chefs long have known that the hearty Irish stout, brewed since 1759 in Dublin, 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 said, especially Irish blues.

“It has a rich spectrum of uses,” said 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,” said Medrich, author 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, said Janet Fletcher, author of the upcoming “Cheese & Beer” (Andrews McMeel). Stout, in particular, she said, 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 said, such as Ireland’s soft, supple Cashel Blue. And though she said she prefers hoppier beers with cheddar, she admires the historic pairing.

“It’s been the cornerstone of many a pub lunch for centuries,” she said.

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 and even Guinness lasagna.

“In recent years people are cooking a lot more creatively with Guinness than they used to,” said the site’s editor, Brendan Spiegel

He pointed to a lasagna – which incorporated Guinness into a salsa verde topping – as the funkiest recipe.

“I don’t know what it wouldn’t go with,” Spiegel said. “It’s definitely a wintery flavor, which is why it works for St. Patrick’s Day.”

Not everyone is enamored of Guinness.

“It’s OK to drink with oysters and to cook with a beef stew, but that’s about it really,” Peter Begg, head of food development for Jamie Oliver Ltd., writes in an email.

But Hartley loves it for its iconic status and 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 said. “But the Guinness will still be there.”

MAIN DISH

Irish Chop Suey

Six 12-ounce bottles Guinness

1 pound 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 scallions, chopped (white and green parts)

In a large stockpot over medium-high, bring the Guinness to a boil. 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.

Meanwhile, in a large, deep skillet over medium-high, combine the ground beef, onion and garlic. Saute 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 scallions.

Makes six servings.

Recipe courtesy Alison Ladman.

SIDE DISH

Caramelized Onion And Guinness Dip

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

In a large skillet over medium, heat the olive oil. 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.

Once the onions have cooled, in a food processor combine them, 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.

Makes 16 servings.

Recipe courtesy Alison Ladman.