For The Absolute Best Espresso Tonic, Choose Your Water Wisely

There is absolutely a time and place for ultra-sweet caramel macchiatos and white chocolate mochas with whipped cream — but it's usually in the fall and winter when we want something warm and cozy to wake us up in the morning. On the flip side, spring and summer are the optimal times to reach for cold caffeinated beverages. And while it's not the most common drink on coffee shop menus in the U.S., an espresso tonic may be one of the most refreshing during the sweltering seasons.

Part of its beauty is in its simplicity. You only need two ingredients to make an espresso tonic: Espresso and tonic water. While the espresso may be in the spotlight here, don't forget to pick an exceptional tonic water brand, too, since the focus is only on these two main components, and you'll be clearly tasting them both. Our No. 1 favorite brand is Fever-Tree for its light sweetness and overall clean taste, and it comes in various subtle, fresh flavors. But we also love brands like Canada Dry, Spectacular Q, Betty Buzz, and San Pellegrino.

If you want to scour the streets (aka the grocery store aisles) for a high-quality tonic water pick, you may wonder: What makes for a superb can, anyway? In general, tonic water is a very simple soda, as it's a sweetened sparkling water (as opposed to club soda or seltzer, which typically has no flavor). The ideal bottle strikes a balance between sweet and crispy, allowing it to bring something extra to your drink while staying light and letting other flavors take center stage. To get more specific, Top Note Tonic founder Mary Pellettieri told Alcohol Professor, "Most classic tonic waters have that quinine bitterness, a lemon-lime top note, with an actual middle level of sweetness."

You'll also want to find a brand with excellent ingredients — like Fever-Tree, our top pick, which uses Sicilian lemons and Central African quinine. But if you want to have a little fun with your espresso tonic, you can find everything from classic to flavored waters on the market. Fever-Tree, for example, makes bottles with lemon, elderflower, or rosemary and thyme notes, while you can choose from San Pellegrino's lemon and orange peel or oak extract-infused cans. Pair these choices with a blueberry syrup or a splash of grapefruit juice, or just enjoy your high-quality, two-ingredient morning beverage as-is.