225g/8oz unpeeled fresh root ginger, finely sliced
175g/6oz/¾ cup caster (superfine) sugar
zest and juice of 2 lemons
1 litre/1¾ pints/4 cups soda water
1 Heat the ginger, sugar, lemon zest and juice in a pan with 600ml/1 pint/2½ cups cold water. Stir well and simmer for 10 minutes.
2 Strain through a fine sieve into a jug. When cool, top up with soda water.