Six months ago, I couldn’t be bothered with ginger-anything. Canada Dry? Gross. Ginger green tea? Meh. Still-stuck-in-your-teeth-2-hours-later ginger chews? I’ll pass. Then I moved to Colorado. Maybe it was just the high altitude warping my gustatory cortex, but more likely it was the ubiquity of ginger beer here that suddenly had me downing bottles of Reed’s and hunting down the perfect mixer for that pinnacle of zippy drinks: the Moscow Mule.

“It’s the drink of Denver,” says Stuart Jensen, bar manager of Mercantile Dining & Provision (one of our Best New Restaurants). And there’s no mistaking it—Denverites love a Mule or Dark ’n‘ Stormy. “My friends from other cities will come here and say, ‘What’s with the ginger beer?’”

So to spice up the go-to drink (even more) on Mercantile’s menu, Jensen subbed out vodka for a spirit that’s been steadily been acquiring enthusiasts—Fernet Branca. The bitterness of this popular Italian digestif is expertly balanced with sweet, acidic pineapple juice and Mercantile’s house-made ginger beer. Add in lime juice and a little Byrrh, a wine-based French apéritif, and you’ve got a spicy-smooth concoction that’s awakening and peppy, perfect as a dinner-palate primer.

Dubbed Falabella (a name that, like most drinks on the menu, stems from an inside joke between employees we outsiders will never understand), Jensen’s creation ingeniously plays off the standard Mule, leaving us smacking our lips for more Fernet.

As you might expect, bartenders are way ahead of us. Behind Jensen’s motive to put this humble spirit on the menu is a growing movement around Fernet Branca that’s something like a secret society game. And unless you’re a bartender, you can’t play.

Tucked in Jensen’s pocket, in bartenders’ pockets around the nation, is a heavy, half-dollar-sized brassy medallion embossed with “Fernet Branca” across its face. Like a cross between Nose Goes and Straws, once someone presents their coin to a group, everyone else antes up with their own. Anyone caught without the token required for this “bartenders’ handshake” is stuck with supplying the group with a round of Fernet shots.

How do you get a Fernet medallion? They’re given to you, which means: 1) You’re a bartender; and 2a) Someone gave it to you; 2b) You traded it with another industry person; or 2c) You got it from an event where the medallions were being distributed. Now, either because being part of a secret club is cool, or because they actually like the taste, more and more bartenders across the nation are toasting at the end of the day with a swig of Fernet.

For the rest of us in the medallionless club, we head to Mercantile and try out the Falabella for a lesson in well-balanced bitters.

Don’t miss: Mercantile’s spring cocktail menu coming out this month. As a farm-to-table restaurant (