• 250 g (8 oz/1 cup) sugar
• 250 ml (9 fl oz/1 cup) water
• 250 ml (9 fl oz/1 cup) lemon juice (about 4–6 lemons)

Bring the sugar and water to a boil, stir until the sugar is dissolved. Add the lemon juice. Leave to cool. Pour the lemon juice into a large jug and top up with approx. 750 ml (3 cups) cold sparkling water. Garnish with slices of lemon and ice cubes.