Blackberry Ice Cream

In a large saucepan over medium heat, cook blackberries, sugar, and lemon juice until sugar is dissolved and berries are soft. Put the berry mixture in a blender and puree for about 1 minute. At this point, you might want to put the puree through a mesh sieve to remove the seeds. If you do remove the seeds, return the mixture to the blender. Add heavy cream and the sour cream and pulse a few times. Pour into a bowl and chill thoroughly. Freeze in your ice cream maker following the manufacturer's directions.