Espresso tonic recipe: fizzy iced coffee the FUKU way

This espresso tonic recipe recreates the sparkling iced coffee on the menu at Friedhats FUKU in Amsterdam's Bos en Lommer: a double espresso poured slowly onto ice-cold tonic. It only works if everything is cold and the coffee goes into the glass last.

FUKU opened on Bos en Lommerweg in September 2018 as the first café of Friedhats, the roastery run by barista Lex Wenneker and Dylan Sedgwick. Almost every coffee in their range can be ordered there as espresso or filter; the espresso tonic is on the menu too. The drink itself is Scandinavian: a barista in Oslo mixed it in 2007, and that same year Koppi in Helsingborg, Sweden, put it on the menu as Kaffe & Tonic. This is our own recipe, with our own ratios.

Ingredients

Espresso tonic is all about order: cold first, then bubbles, the coffee last.

• 18 g freshly ground espresso coffee, ideally a fruity, light-roasted bean
• 120 ml tonic water, chilled for at least 2 hours
• 5 to 6 large ice cubes
• 1 strip of orange or lemon peel (optional)

Method

1. Put a 250 ml tumbler in the freezer for 15 minutes. A cold glass will not warm the tonic, and cold tonic holds its carbonation for longer.
2. Fill the glass to the rim with ice. A full glass of ice melts more slowly than a few cubes, so the drink dilutes less.
3. Pour the tonic slowly down the side onto the ice until the glass is about two thirds full.
4. Pull a double espresso: 18 g of coffee, 36 to 40 g in the cup, in 25 to 30 seconds with water at 92 to 94 °C. A short, sweet extraction brings fruit and acidity; an over-extracted shot turns harsh next to the bitter quinine in the tonic.
5. Pour the espresso straight away, very slowly, over the back of a spoon onto the tonic. Hot coffee and carbonation react violently; the spoon keeps the foam under control and lets the coffee float in a layer on top.
6. Twist the peel over the glass so the oils land on the foam, and serve without stirring.

Tip: choose your tonic the way you choose your coffee

The tonic decides half the flavour. A dry Indian tonic lets the coffee speak; a citrusy Mediterranean tonic suits Ethiopian and Kenyan beans. If a 1 to 3 ratio is too punchy, move to 1 to 5. For more places that take this seriously, see our list of the best coffee bars in Amsterdam, with FUKU at number one.

Espresso tonic recipe: frequently asked questions

Why does my espresso tonic foam over? You are pouring the coffee too fast or the tonic is not cold enough. Pour over a spoon.

Can I use cold brew instead of espresso? Yes. Cold brew concentrate makes a softer, less acidic version that barely foams, but you lose the layer of crema.

Which coffee works best for espresso tonic? A light roast with fruity notes, such as a washed Ethiopian or Kenyan coffee. Dark blends make the drink bitter and flat.