From The Designer's Cookbook by Tatjana Reimann, Caro Mantke, and Tim Schober
2 cups (250 g) fresh blueberries
5.4 fl. oz. (16 cl) crème de violette (clear)
2.7 fl. oz. (8 cl) gin
0.7 oz. (20 g) sugar
7.4 fl. oz. (220 ml) water
For the syrup, heat 0.7 oz. (20 ml) of sugar with 0.7 fl. oz. (20 ml) of water in a small saucepan and bring to a boil. Stir until sugar has dissolved and then remove from stove and let cool.
For the blueberry water, thoroughly wash blueberries and add to a small saucepan. Pour in a bit of water and bring to a boil. Simmer until blueberries fall apart and then pass through a fine sieve. Pour the blueberry water into a bowl and set aside. Next, rinse the sieve with the blueberry skins with 6.7 fl. oz. (200 ml) of water to create a violet-colored liquid.
For each cocktail, add 0.6 fl. oz. (2 cl) of gin, 1.2 fl. oz. (4 cl) of crème de violette, 1/3 fl. oz. (1 cl) of syrup and crushed ice to a cocktail shaker and shake for 10 seconds. Strain into a cocktail glass and fill with 0.9 fl. oz. (3 cl) of blueberry water.