Try a new-school martini at this hidden Old City backroom bar

Ice-cold, crystal-clear, and bracing, the classic martini has never fallen out of fashion. But its opaque, caffeinated counterpart — the espresso martini — now appears on so many menus that there’s no denying: The original has taken a temporary backseat.

Still, martinis dry, dirty, and otherwise are regaining ground in Philly and beyond, thanks to experimental bartenders. They’re olive oil-washing the gin, infusing the vermouth, and tinkering with ratios, ingredients, and garnishes to come up with novel takes on a timeless formula. How far can you push the boundaries and still wind up with a martini? Perhaps only the customer can say.

A prime example of the new wave of martinis is on the summer menu at Old City’s Art in the Age (116 N 3rd St.). Head to the copper-topped bar all the way to the back of the lifestyle boutique-turned-cocktail supply store to try it alongside other inventive seasonal cocktails, including the Watermelon Salad (vodka, rosé, feta brine, and black pepper bitters) and the Fine Diner (whiskey, cherry vermouth, Aperol, lemon, and seltzer).

The Picnic Martini ($13) arrives slightly cloudy, dabbed with a few drops of olive oil, in a frosty coupe. A hefty dose of New Liberty’s Snug Harbor Gin makes it boozy, but it’s also balanced with gentle sweetness, a hint of lemon, and a little salinity.

“It definitely feels like a martini,” says general manager Craig Richie, “but if you’re looking for the kind of martini that is effectively just cold vodka ... it is not going to necessarily satisfy that craving.”

Art in the Age’s bartenders combine local cherry tomatoes with dry vermouth and let the mixture sit overnight to infuse the botanical spirit with sweet and savory notes. “That’s the traditional martini part of it really and then we start to add a couple of extra little touches,” Richie says.

To create a full picnic experience, they blend tonic syrup (botanical and bitter) with peach syrup — but not a basic syrup with peach flavor. This is pêche syrup made by Bacanha, a French company that specializes in what Richie describes as “dry simple syrup, because it concentrates more on the flavor than the sweetness.”

A quarter ounce of the syrup blend plus a quarter ounce of lemon juice give the Picnic Martini that bright, summery quality. The drink is finished with dashes of saline and olive oil (for a savory note) and a speared cherry tomato half covered in flaky sea salt. And even though this is definitely a cocktail bar’s cocktail, you can buy everything you need to recreate it at home right there in the bar.

“We try and pull a couple ingredients off of the shelves for every menu,” Richie says. “This recipe involves some infusion, but it’s not difficult.”

The Picnic Martini will be on the menu through September, but there’s another new-school martini to try — the Weenie Martini — on select summer weekends. Though they experimented with hot dog water and pork-infused vodka, Art in the Age ultimately eschewed that in favor of all the things that go with the hot dog. Potato vodka and sesame oil nod to the bun, tomato vermouth evokes ketchup, pickle juice acts as relish. It’s garnished with a cornichon, a cherry tomato, and a hot dog wheel.

The Weenie Martini raises money for Morris Animal Refuge ($5 of its $17 price tag go toward the rescue). Look for it next on Aug. 25-27 and Sept. 22-24.