Philadelphia ? Imagine beginning the day with beer waffles, lunching on beer potato salad and finishing a fine meal with beer chocolate mousse.

When we talk food and beer, we’re not talking tailgate fare, we’re talking haute cuisine, the best foods restaurants have to offer.

If you cook like some cutting-edge chefs, beer isn’t just a drink, it’s an herb, a flavor, an essential cooking ingredient. A food.

Brews lend texture and interest without overpowering, perfectly seasoning everything from risotto to mousse, chicken to shrimp, and especially summer dishes. Menus not just at brew pubs but at tony restaurants have been following this trend more and more, as chefs experiment and add wheat beer to chicken, Jamaican beer to fish, and Pilsners to Mediterranean and Moroccan foods.

The brew-ha-ha can be traced to the explosion of microbreweries in the early 1990s, which made beers like Sierra Nevada Pale Ale as commonplace at bars as Budweiser. For chefs, simply pairing beer with dinner wasn’t nearly as exciting as splashing it in the food.

Nationwide, the number of small breweries catering to beer lovers has been growing, offering an infinite selection. America’s small brewers grew an average of nearly 10 percent last year, according to the Brewer’s Association of America.

All this has sent the beer-cooking trend into full froth.

Brian Duffy, formerly of McCormick and Schmick’s and now at Manayunk Brewery, began using stout beers in salad vinaigrettes. Now he incorporates them into main courses. Nodding Head Brewery and Restaurant Executive Chef Andrew Maloney makes a demi-glace with a grog, and braises mussels in a pale ale.

“Most people have paired beer with food, but beer in food gives it a whole different flavor,” said Maloney.

University City’s La Terrasse Chef David Grear has been using beer for the past few years, including Colt

45, a high-alcohol-content malt liquor he adds to mussels with oregano and butter. A Colt 45 delivery to the French restaurant was once returned when a worker thought it was sent by mistake and didn’t know Grear used it in his recipes.

Grear also experiments with lagers to make batter for fried chicken fingers coated in crumbled pretzels.

“We’re all looking for the next new thing,” Grear said. “As a chef, I like beer more than wines. Chefs are just looking for an old way to do a new thing.”

Perhaps the most soup-to-nuts beer use occurs in Tim Schafer’s kitchen. Schafer, a New Jersey restaurateur and chef known as the Brew Chef, is winning national acclaim with appearances on the Food Network and local cable television, making everything from breakfast to dessert with beer. Schafer knows food is naked nothingness without hops.

For him, ales and lagers are the essence of a meal. Raspberry brews are for sweet desserts, lagers for chili. Stouts enhance ribs and meats, and pale ales rev up seafood. Brew cooking to him is an art, a passion. A must.

“Beer is an integral part of my cooking repertoire,” said Schafer, who attracts a throng of groupies as he travels the country to dozens of beer events, sampling thousands of beers, collecting ideas and experimenting. “There is a lot of tradition to beer which I continue to learn.

“Application of the beers is key. You don’t put wine in every dish, just like you don’t put beer in every dish,” Schafer continued. “I’ve experimented with just about every beer, and people say there’s something different , but they don’t know what it is.”

Schafer, who is writing a cookbook about his adventures, “Beer: Not Just For Breakfast Anymore,” opened Tim Schafer’s Cuisine in northern New Jersey’s tony, suburban Morristown in the early 1990s. When microbreweries began to take off, customers demanded label-specific stouts and India pale ales (IPAs) at the bar. Schafer began to taste the brews. Intrigued, he splashed them into foods.

“I started to see an influx of beers, and I started to experiment with the food,” Schafer said.

Schafer doesn’t just pour beer indiscriminately into a chili pot, and he cringes when asked to do a ho-hum “beer-can chicken” on the grill (an open can of brew is placed upright inside a chicken on the grill, imparting brew flavor). Instead, he mixes raspberry beer into chocolate mousse, or ales and stouts into waffles to make them dark or light blond or chocolate.

And rule No. 1: Don’t be a beer snob. Schafer uses Budweiser for braising.

When Schafer first experiments with a beer, he keeps a few keys in mind. First, only cook with a beer you’d drink.

“The beer must taste good. It’s really just like any wine you cook with,” Schafer said.

Next, remember that adding beer to food will impart not only flavor, but color. When making blond waffles, use a light beer, not a dark beer like Guinness. When stewing, creating stock or braising meat items that are generally slow-cooked are on the agenda, darker beer is often better.

And finally, please, please, follow your gut not beer gut instinct.

“It’s hard to mess up with beer,” Schafer said. “The key is to experiment, or splurge for a good beer, and add it slowly. You can always add more.”

Or drink the leftovers.