For a berry swirl, add some sweetened crushed Black Currants during the last minute of churning. The swirl may become icy after the ice cream is frozen, so soften slightly before serving.
Puree Black Currants, 2 tablespoons sugar, and CurrantC™ Nectar in processor. Let stand 15 minutes. Strain puree into bowl, pressing on seeds to extract as much fruit as possible; discard seeds.
Whisk yolks and remaining 1 cup sugar in medium bowl to blend.
Bring milk and cream to simmer in heavy medium saucepan. Gradually whisk hot cream mixture into yolk mixture; return custard to pan. Stir over medium heat until custard thickens enough to leave path on back of spoon when finger is drawn across, about 6 minutes (do not boil).
Immediately pour custard into large bowl; mix in vanilla.
Place bowl of custard over another large bowl filled with ice and water and cool, stirring occasionally, about 40 minutes. Stir in Black Currant puree.
Process custard in ice cream maker according to manufacturer's instructions. Transfer ice cream to large container, cover, and freeze until firm, at least 4 hours and up to 2 days.