Rinse and drain the blackberries and puree in blender or food processor along with wine and sugar until smooth, about 1 to 2 minutes. Press through strainer to remove the seeds. Stir in lemon juice, season lightly with salt and pepper. Cover and chill several hours or overnight.
To serve, ladle the gazpacho into chilled soup plates, footed glasses or bowls. Drizzle or spoon on the sour cream and scatter with raspberries and blueberries. (You may not need all the raspberries and blueberries - they can be treats for the cook.) Top each serving with a mint sprig or coarsely chopped mint.