Meet the Espresso Tonic, Iced Coffee's Bubbly New Cousin

Tonic's best friend is no longer gin. In fact, the bubbly quinine-laced beverage has been hanging out with coffee as of late. Together, they yield a cold, caffeinated and carbonated drink that's quickly growing in popularity. And while cafes across the country are beginning to experiment with coffee tonics, this summer beloved Portland-based roaster Stumptown will roll out a version of the drink at all 10 of its cafes.

Though coffee and tonic may sound like an odd couple, Steven Latham, manager of Box Kite, a speciality coffee shop in New York City, says that quinine's "bright and citrusy flavor" pairs well with the brightness and floral notes of many espressos.

The idea of mixing tonic water and coffee is not an unfamiliar one. According to Latham, the drink finds its origins in barista competitions. Competitors are required to create signature drinks, and many of them "combine elements of tonic and coffee." From there, versions of espresso and tonic have made it on to the menus at a handful of speciality coffee shops on the West Coast like Saint Frank Coffee in San Francisco, and around the world at Koppi, a cafe and roaster in Helsingborg, Sweden. Now, espresso tonics are starting to hit cafe menus in the U.S., namely at East Coast speciality shops.

Box Kite first put a version of an espresso and tonic drink — which the shop refers to as a "Spro and Tonic" — last fall. It was a riff off one of Latham's signature drinks from a recent barista competition that featured muddled grapes and sorghum syrup along with the namesake components. As the seasons changed, the shop eventually switched over to a simpler version made with three components: Fever Tree tonic, a shot of espresso and ice.

Photo: Pulling an espresso shot on top of the tonic.

To make the drink, Box Kite baristas simply load a glass with ice, fill it about three quarters of the way with chilled tonic, and then top it off with an espresso shot — typically from roasters like Madcap (MI) and Ritual (SF). Often, baristas pull the espresso shot directly on top of the tonic and ice mixture, forgoing the process of first pulling it into a cup and then pouring the espresso from cup to glass.

Meanwhile, Stumptown also has a coffee and tonic drink "in the works," according to Diane Aylsworth, the brand's marketing director. The beverage, which goes on sale this summer, is simply named Cold Brew Tonic. However, instead of using espresso, Stumptown will build its version with one part cold brew coffee plus two parts Fever Tree tonic water over ice with a Luxardo maraschino cherry garnish. Aylsworth says the drink has a "refreshing sipping cocktail appeal."

Photo: Yelp/Flickr

While the types and styles of coffee used to make the drink may change, Fever Tree appears to be the tonic of choice. Box Kite, Saint Frank, and Stumptown have already pledged allegiance to the brand. It's popularity most likely comes down to the quality of the product: Founded in 2005, Fever Tree is crafted with eight botanical flavors and has no artificial sweeteners. "Fever Tree is just really good tonic," declares Latham.

So are coffee tonics the new drink of the summer? For Latham, it's a firm, "Yes." The Spro and Tonic is one of Box Kites most popular drinks, and as the weather warms up, orders are increasing. "People are really loving it," he notes, "We're never taking it off the menu."