The Spanish Gin & Tonic never went away. A blockbuster drink in the United States about a decade ago, Spain’s gintónica was noted for voluminous balloon glasses (copas de balón) filled with specialty gins, artisanal tonics and a garden’s worth of garnishes. Though it has taken a back seat to flashier drinks, it held steady on many menus, and lends itself to customization at home.

The gintónica has roots in Spain’s Basque region, “sometime between 1999 and 2008,” says Keli Rivers, brand ambassador for Sipsmith Gin and the former bar manager and “Ginnoisseur” at the San Francisco bar Whitechapel. She pinpoints as the epicenter San Sebastián, where forward-thinking chefs would gather for Lo Mejor de la Gastronomía Congress (The Best of Gastronomy Conference) to share ideas, showcase avant-garde techniques and most of all, blow off steam. Gathering at spaces such as Coctelería Dickens or El Museo del Whiskey, one of the chief activities was, Rivers says, “drinking one of the many gins stocked in a large wine glass with plenty of ice, cooling down the warm evenings.”

Eventually, gintónica variations began showing up on the menus of Michelin-starred restaurants like El Bulli in Catalonia, “garnished with items that enhanced what was in the gin.”

By 2013, most of Europe was aware of Spain’s affection for the gintónica; By 2014, the Spanish Gin & Tonic, as it became known here, made its way stateside. Consumers cozied up to copas filled with what Rivers characterizes as “large fruit salad cocktails,” abundantly garnished with colorful citrus or cucumber wheels, fresh herbs and free-floating juniper berries or peppercorns.

Though it’s no longer a novelty, the Spanish G&T remains a staple at many bars. Part of the appeal, says Marshall Minaya, beverage director at gin-focused New York bar Valerie, is that the Spanish version transforms the G&T from an equal-parts highball to a session drink. “A proper Spanish-style Gin & Tonic has a one-to-four ratio of spirit to tonic,” he notes.

Matching up gin and tonic combinations based on guest preferences is part of the ritual, although Valerie also offers a regular menu of G&T riffs anchored by specific flavors (“Spicy,” “Citrus”), accented by small amounts of liqueurs, tinctures or bitters. For example, the Tart G&T pairs Japan’s Roku gin with a bitter lemon tonic, along with small measures of herbaceous Suze and citrusy yuzu bitters. Though the drink is served in the requisite goblet, the garnish is restrained: just shiso leaves.

The surge of small-batch gins from craft distilleries also has stoked exploration with the Spanish G&T, says Natasha Bahrami of The Gin Room in St. Louis, Missouri. “As more small-batch gins started hitting the market, there began a bigger push from bartenders, brands and marketers to pair these craft spirits and their individual flavor profiles in ways that highlighted their botanicals,” she explains. Before long, the Spanish G&T in particular became a welcome template for achieving this: Often the garnish was used to amplify or signal a gin’s botanical profile.

As the flavor identities of these gins have become increasingly varied, commercial tonics have proliferated. Options now include specialty flavors such as Lime & Yuzu (Fever-Tree), Elderflower (Q), Pink Grapefruit (Fentimans) and Cherry Blossom (Thomas Henry). But the universe of tonics remains much smaller than the number of gin bottles, so The Gin Room makes its own tonic syrups, designed to be lengthened with soda water, to fill in the flavor gaps. The Garden G&T, for example, matches the spicy, citrusy profile of Chicago’s Koval Gin with the bar’s apricot-forward Spring Tonic.

The Spanish G&T also matches current demand for effervescent drinks, from the proliferation of the highball and the spritz to the deluge of hard seltzer, says Sarah Morrissey, bar director at Basque-inspired restaurant Ernesto’s on New York’s Lower East Side. “All of these drinks have subtle delicious flavor, a good bubble and are refreshing,” she says.

For the moment, Ernesto’s has only a beer-and-wine license, so she’s serving a vermouth blend with tonic. But when the time is right, she has a Spanish-style G&T made with Spain’s Xoriguer Gin de Mahón waiting in the wings. It pays homage to the power of effervescence but also the visual appeal of the Spanish-style G&T. Morrissey, like many other bartenders committed to the variation, has found ways to evolve it to suit her individual aesthetics.

In her take, she tames the usual tangle of garnishes by freezing some of the accouterments—a blanched spray of rosemary, lime peels, juniper berries—into an ice block. This comes with another benefit many Spanish G&T-lovers will understand, she says: “I put the juniper berries in the ice because I was sick of them getting stuck in my straw.”