Coffee buzz: Tonic and espresso at Roosevelt Coffeehouse

Roosevelt Coffeehouse, our favorite new coffee shop with a cause, got a national nod this week. In a Bon Appetit blog about this summer's new coffee trend-espresso or cold brew coffee poured over tonic water and ice-the Discovery District shop was mentioned for its Black Tonic ($5), which they started pouring on Friday. It's their straightforward take on the fizzy coffee drink that's trending across the country.

Founder Kenny Sipes said he recently read about the concoction in a coffee trade mag, loved the way it sounded and had to offer it. And, of course, we had to try it.

The technique resembles that of a latte. In a glass of ice, a whole bottle of Fever Tree soda is slowly poured down and around the side of the cup. Then, a shot of Stumptown espresso is drizzled just as gently overtop, forming a tall, tan, foamy head.

"Drink the fizz while it's still fresh," the barista advised as he slid the drink across the counter to me. "The coffee's good, too, but you need to try both."

It's great advice. Bring the glass to your nose and the fizzy top smells slightly sweet, but tastes like bitter, effervescent espresso. It's an odd mind game, and is one of the best parts about the drink. The coffee itself tastes exactly like you'd expect-espresso carbonated with tonic water-albeit more refreshing than your standard cold coffee.

We'll see if it catches on.