In cocktail sharker, muddle blackberries, and coarse sugar until berries release juices. Top with ice, lemon juice, simple syrup, and black currant flavour. Shake until cold.
Strain into prepared glass and top with soda water. Garnish with thyme and blackberries. Give it a stir, sip and enjoy.
Notes
Make it a cocktail by adding an 1 ½ ounces of gin or vodka.