Why is R&D, the trendy Fishtown cocktail bar, serving White Russians?

I thought the craft cocktail revolution had more or less left behind the White Russian, and I was OK with that.

Then, as I examine the newest menu at Philly’s latest high-concept cocktail bar, Fishtown’s R&D, there it is. In fact, it’s highlighted as one of just nine drinks on a menu that riffs on the 1950s as conceived by restaurateurs who were not actually alive in the ‘50s: a vision of Mad Men-style three-martini lunches during the workweek and umbrella-shaded rum drinks on the weekend.

Of course I have to order it — and then I get the joke. This White Russian ($12) is, in fact, very 2018. Though it’s sweet, with hints of espresso and chocolate, it is clear, not milky-looking. Its creaminess is derived from clarified milk punch, a trendy ingredient that imparts a cream-soda richness without the heaviness of actual cream. It’s cooled by a large, clear ice cube (part of a “full ice program” that includes special-ordered clear ice that’s sliced with a bandsaw or hand-chiseled) and served in a faceted rocks glass that was unearthed on one of many thrifting trips by bar staff just to accommodate this menu.

All that sounds extreme. But R&D is, as its name suggests, a mad-scientist’s approach to a cocktail bar.

The three-month-old bar represents the afterlife of Root, Greg Root’s restaurant and wine bar that had loyal fans but, according to Root himself, did not have the kitchen space to support its ambitions. After the team opened Suraya — the enormous destination restaurant down the street — they wanted to recast this space to scale with its real estate. So they opted for a modest snack menu ($4-$8) that borrows notes from Suraya (charred long hots with labneh, hummus with cashew dukkah, whipped ricotta with date syrup).

That put the cocktails front and center. And rather than settle on one drink menu, they opted to overhaul the whole thing quarterly, with a new theme each time.

“It’s kind of crazy,” Root said. “It’s not opening a new bar every three months, but it’s close to it.”

Round one involved pre-Prohibition cocktails, an obvious choice. For the second menu, which will remain through April 2, they veered toward the unexpected.

“The 1950s wasn’t known really for its cocktails,” said Aaron Deary, who developed the drinks. “The goal this time was to do something a little more fun.”

When I stop by on a Friday night, it doesn’t exactly feel like stepping into the ‘50s. In fact, I have trouble detecting what, if anything, has changed from Root’s original decor of stylish mod furniture, dim lighting, geometric tile, and a cozy, horseshoe-shape bar. It’s more of a suggestion: a soundtrack that tends toward Louis Armstrong, Ella Fitzgerald, and Ray Charles; a bartender’s uniform that includes skinny ties (along with tattoos and gauges); a cheerfully retro paper menu.

That menu, though fun to look at, is hard to read, particularly as it mixes fake ads with actual, useful information, like the fact that beer and wine are available. It also leaves out details on a unique offering: tableside service via a bar cart. (To clarify what the menu doesn’t: this is mostly available on weekends and you don’t need to organize it ahead of time. There’s roughly a $3-per-drink up-charge, and a two-person minimum.)

It’s probably for the best, though, that the ‘50s theme isn’t too authentic.

Instead, we get offerings like the Three Martini Lunch ($15): a trio of 1.5-oz. martini sliders including a Gibson, a Vesper, and a Martinez. My favorite is the latter, made with genever, sweet vermouth, maraschino liqueur, and a nearly black cherry rolling around the bottom of the glass. The Blue Hawaiian ($13) here, instead of Malibu, is made with rum that’s been fat-washed in Coco Lopez and mixed with fresh-squeezed pineapple juice.

“It was a challenge to balance these drinks for the modern palate,” Deary said.

1206 Frankford Ave., 215-515-3452, rdphilly.com

When to go: Follow it on Instagram for events like jazz and industry nights. Otherwise, it’s open 6 p.m.-1 a.m., Monday-Saturday.

Bring: A date you want to impress. Your friends who feel too old to drink at Garage.

What to order: A boozy float ($9) with custom ice cream flavors developed by Suraya pastry chef James Matty, like the Golden Dream, with blood orange Pellegrino, Gran Marnier, cognac, and crème de cacao gelato.

Bathroom situation: Judging by Instagram, it’s selfie-worthy: lined with mirrors and clean enough.

Sounds like: Early in the evening, it’s low-key with ‘50s jazz stylings. Later, it steps out of character with old-school hip-hop, at a buzzing 93 decibels.