In a bowl of cold water, gently clean the blackberries. Be sure to remove all debris and any soft or discolored berries.
In a food processor or blender, combine the berries, water, sugar, lemon juice and wine. Process or blend mixture until smooth. Add the whipped egg white and stir until thoroughly blended. Chill mixture.
Freeze (churn) cooled mixture in an ice cream machine, according to the manufacturer’s directions. Garnish with fresh blackberries and mint leaves.