Adapted from – Cooking Light
4 Cups cold water, divided
3 Cups blackberries
3/4 Cup sugar (can increase to 1 cup if your blackberries are especially tart)
1 Cup freshly squeezed lemon juice
2 Cups sparkling water
In a blender or food processor, combine the blackberries and 1 cup of the water.
Puree until smooth, then press the mixture through a fine-mesh strainer to remove the seeds.
In a pitcher, combine the blackberry puree, sugar, lemon juice, and the remaining water.
Stir well to dissolve the sugar.Chill until ready to serve, and top with the sparkling water just before serving.