Makes 1 quart
1 cup Heavy cream
½ cup Granulated sugar
4 Egg yolks
1 pinch Salt
1 pint Blackberries, blended and strained into 1 cup of purée
¼ cup Sour cream
½ Vanilla bean, split and scraped
Heat cream and vanilla bean in a saucepan. Whip egg yolks and sugar in a bowl until pale and fluffy. Bring cream to a rapid boil. Turn heat off and pour while whisking slowly into the fluffy egg yolk mixture. Strain with a fine mesh strainer into a clean mixing bowl, return the vanilla bean to the custard. Allow to cool over an ice bath in your refrigerator for at least 4 hours or loosely wrapped over night. This step will mature the custard leaving a very smooth rich flavor.
When ready to pour into the ice cream machine, take out the bean and whisk in the Blackberry puree and the sour cream. Process according to manufacturers instructions.