Why a paste makes the difference

Cocoa powder does not dissolve in the same way as sugar. It needs to be dispersed through the drink, and a small amount of liquid lets you work through lumps before they are lost in a full glass. Starting with cold milk and a heap of cocoa often produces tiny dry islands that remain even after enthusiastic stirring.

Use unsweetened baking cocoa here, not a ready-sweetened hot chocolate mixture. The latter can contain milk powder, starch and added flavourings, so it changes both sweetness and texture. If it is all you have, follow its label for a cold drink and omit the recipe's sugar until you have tasted it.

Balance bitter and sweet

Coffee and cocoa both bring bitterness. The modest sugar quantity rounds off those edges without turning the drink into a dessert sauce. Dark-roasted coffee may need a slightly different balance from a lighter roast, but add sweetness in small amounts rather than masking the coffee altogether.

Stir once more halfway through drinking if some cocoa settles. That is normal for a homemade cocoa drink without commercial stabilisers. A wide glass is easier to mix than a narrow bottle, and there is no need for a blender when the paste has been made properly.

What you'll need

  • 60 ml freshly brewed espresso
  • 2 tsp unsweetened cocoa powder
  • 2 tsp caster sugar, or to taste
  • 160 ml cold milk
  • 100 g ice cubes

Let's make it

  1. Put the cocoa and sugar into a heatproof cup. Add one tablespoon of the hot espresso and stir firmly into a glossy paste, pressing out dry pockets with the back of a spoon.
  2. Gradually stir in the remaining espresso. Cool the cup in a shallow cold-water bath for roughly 15 minutes, keeping water out of the coffee.
  3. Fill a tall glass with ice, pour in the milk and add the cooled chocolate coffee. Stir from the bottom until the colour is even. Taste before deciding whether it needs a little extra dissolved sugar.

Make it your own

For a stronger chocolate note, stir 10 g finely chopped dark chocolate into the hot espresso before cooling. It may leave a little fine sediment when cold.

Decaffeinated espresso can replace the regular espresso without changing the method.

Keeping it fresh

Serve over ice immediately. The un-iced mocha can be covered and chilled promptly at 5°C or below for up to 24 hours, subject to the milk's use-by instructions; stir well before serving.

Allergen notes

Contains milk. Added chocolate may contain soya or carry nut warnings.