Lots of things vie for your attention at Madame Jasmine. There’s the fuzzy zebra-print wallpaper, for starters, and the transgender Barbie dolls that mark the entrance to the unisex bathrooms, to say nothing of the cool, look-at-me clientele. But it was the miniature oak barrel at the end of the bar that caught my eye one night last spring. It had a little metal spigot on the back, and on the front was scrawled, in chalk: “Vermut 2€.”

The last time I’d heard of anyone drinking vermouth (“vermut” if you’re Catalan) was when my grandmother sloshed it into one of her sticky-sweet Manhattans. Yet here it was, in a Barcelona hipster bar, served by a generously pierced bartender, who wordlessly plunked a big green seltzer bottle on the table along with our round of drinks and walked away.

Turns out that Spain is in the midst of something of a vermouth renaissance. Though it never disappeared from the old-school spots, the tawny-colored liquor — which can be served up or on the rocks, with or without a squirt of soda, and garnished with a lemon twist, an orange slice, a green olive or nothing at all — has recently started turning up all over town. Even the Adria brothers (of El Bulli and every trendy restaurant in Barcelona fame) have gotten in on the act with their recently opened vermutería, Bodega 1900.

Details: Barcelona vermouth

Wooden barrels are used in the distillation of vermouth at Bodega Yzaguirre the rural area of Tarragona, Spain. After decades out of fashion, the vermouth tradition is back in Barcelona. (Maya Kroth)

Though vermouth’s modern origins are often pegged to Italy, wine fortified with herbs has been used medicinally in many cultures for thousands of years. And Spain’s Catalonia region is home to a generations-old vermouth industry of its own. A blend of white wine fortified with extra alcohol, sugar and each distillery’s secret mix of herbs, the local hooch is different from its commercially produced Italian cousins, such as Martini and Cinzano, and usually about half the price. Dozens of distilleries have been making vermouth in regions of Catalonia for more than a century, selling it both in labeled bottles and directly to bars, where it’s poured from a barrel.

In Barcelona, to “fer un vermut” (literally “to do a vermouth,” but broadly meaning “to go get a drink”) is a ritual with some specific do’s and don’ts — one of which I learned the embarrassing way when I ordered a round one Saturday night and caught the barkeep trading a glance with a guy at the end of the bar.

“What was that about?” I asked the guy, who introduced himself as Jorge.

“It’s a guiri thing,” he explained, using Spanish pejorative slang meaning “foreigner.” “Vermouth is a thing you do on Sundays, after Mass and before lunch.”

Originally, Jorge continued, herbaceous vermouth was designed to “open the appetite” before a big meal. Then people started switching to beer or wine a half-century ago, and vermouth fell out of fashion. Recently, though, it’s in vogue again, much like old-timey mustaches, suspenders and other grandpa-traditions. A recent promotion designed to revive the habit among the younger generation features a Web site plastered with photos of young guys with flippy hair and Warby Parker sunglasses.

But I understood from Jorge that drinking vermouth on a Saturday night in Spain was akin to ordering a mimosa at a nightclub in the States. It’s just not done, unless you’re from out of town — and I didn’t want to be outed so quickly.

Next time, I wanted to get it right. So one bright Sunday around noon, a friend and I jumped on bikes and pedaled the broad, leafy boulevards of the L’Eixample neighborhood to Morro Fi, a capacity-18 vermouth bar in a storefront just large enough to park a Smart Car in. The bar’s name translates loosely as “refined taste,” and the folks behind Morro Fi sure know the proper way to “fer un vermut.” The scene was very metropolitan-brunch chic, the sidewalk tables filled with stroller-pushing 30-somethings clinking glasses and noshing on seafood and various pickled things: smoked tuna, olives, anchovies, sardines — sharp, salty flavors that nicely complement the herby-sweet vermouth.

I started to see how the ritual is as much a part of the appeal as the drink itself. And at around 15 percent alcohol by volume, vermouth offers the best bang for your euro, which may partly explain its resurgence.

“I think in times of crisis, people are returning to drinks that are cheaper, and older values,” offered Cesar, a Morro Fi employee, when I quizzed him about vermouth’s newfound popularity.

The next day, I asked the same question of a staffer at wholesale wine shop Bodega Maestrazgo.

“Why does anything come into style?” he shrugged. All he knew is that the store was selling about twice as many liters of vermouth per week as it had a year earlier. The 61-year-old bodega recently decided to open up a vermouth tasting room in the back. For about $3.50, you get a simple, unadorned glass of vermouth plus a tapa of Cantabrian white anchovies. I shelled out a little extra for a whole bottle, poured straight from the big oak barrels that line the walls, to take home.

My curiosity piqued, I decided to make a trek to the source to see how my new favorite quaff is made. At Bodega Yza­guirre in rural Tarragona, the same basic recipe has been in use since 1884. The place is all stainless-steel vats and wooden barrels, and it smells amazing, redolent of the 200-odd herbs that are cooked down to give the vermouth its aromatic flavor. The blend includes florals such as verbena and star anise; citrus, including lemon balm and pomelo; spices such as cardamom and nutmeg; and bitter herbs like Roman chamomile and “ajenjo,” the Spanish word for wormwood (or, in German, “wermut”).

“The Germans are the fathers of today’s vermouth, following the process that Hippocrates invented,” explained Josep Pomerol, the bodega’s technical director. The herb extract ages in oak barrels for six months, then white wine is added, along with a burnt-sugar syrup, which lends the drink its caramel color and takes the edge off the bitterness.

Bodegas y Destilerías Lehmann, an urban distillery in the town of Tortosa, has been in the herbed-wine business even longer, since 1870. Fifth-generation distiller Emilio Lehmann showed me how the herbs are macerated and pressed in individual batches, by hand, the way his great-great-grandfather did it 144 years ago.

“Vermouth is a product that we’ve always had, but maybe even we didn’t give it enough credit,” he said. “Now we see that the demand has been awakened.”

But it’s not just vermouth itself that’s being revived; it’s the whole social context. “Here in Tortosa, we’ve always had a vermouth tradition, but just go anywhere else and the traditional Sunday vermouth was replaced by the culture of wine,” he said. “You can have a glass of wine anytime, but vermouth has a very definite time slot. When it’s vermouth time, you have a vermouth.”

In Barcelona, it seems, vermouth’s time has come. Again.

Kroth is a freelance writer.