For 8 glasses
For the Rhubarb Syrup
1,2 kg rhubarb, peeled and diced
480 g castor sugar
450 ml water
For the Rhubarb Lemonade
To prepare the rhubarb lemonade first combine the rhubarb, sugar, and water in a large saucepan.
Cook over a medium heat, stirring frequently for 20-25 minutes until the rhubarb is soft and the syrup has slightly thickened.
Strain the syrup through a fine sieve lined with muslin or cheesecloth, sat over a bowl.
Press the rhubarb against the side of the sieve with the back of a spoon to extract as much syrup as possible.
Pour the rhubarb syrup into a jar, seal well, and chill until ready to serve.
Pour 50 ml of rhubarb syrup into serving glasses.
Top up with chilled sparkling water, stir briefly, and garnish the rhubarb lemonade with lemon slices and mint leaves before serving.