Espresso over tonic water is a strange idea until you try it. The quinine bitterness meets the coffee's acidity and both come out sweeter for the meeting. It takes two minutes, and it lives or dies on temperature — everything in the glass must be cold before the espresso arrives.
What you need
- 18g of coffee, ground fine
- A 36g double espresso
- 120ml of tonic water, chilled hard
- A tall glass, filled with ice
- A wedge of calamansi
The method
- Fill the glass to the top with ice. More than looks sensible.
- Pour the tonic down the side of the glass to keep the carbonation in, and let it settle.
- Pull the shot.
- Pour the espresso slowly over the back of a spoon so it floats and layers.
- Squeeze the calamansi over the top and drop it in. Serve with the layers intact and stir at the table.
Temperature is the whole recipe
Warm tonic and a hot shot make a flat, bitter drink in about thirty seconds. Chill the tonic overnight, chill the glass, and use more ice than feels necessary. The espresso should be the only warm thing in the glass, and only briefly.
Which tonic
Use a dry tonic with real quinine and as little sugar as you can find. Sweet tonic against coffee gives you a cola note that is difficult to unhear. If the drink tastes flabby, the tonic is almost always the reason.
Which coffee
This wants a light roast with something to spare, because tonic will flatten anything shy. Cerrado, our lightest roast, carries milk chocolate and roasted almond already, and against quinine it reads closer to a spiced tonic than a plain one.