Wild Blueberry Gelato

Blueberries give this frozen treat a vibrant color. For best results and flavor, cook the blueberry mixture in a non-aluminum skillet.
Combine the first 4 ingredients in a medium saucepan and bring to a boil. Reduce heat to medium; cook for 10 minutes. Place the mixture in a blender; whisk until smooth.Beat the sugar and egg yolks in a large bowl with a whisk until thick and pale (about 5 minutes). Heat the milk over medium-high heat in a small heavy saucepan to 180 ° C or until tiny bubbles form around the edges of the pan, stirring frequently (do not boil). Add a third of the hot milk mixture to the sugar mixture, stirring with a whisk. Gradually add to the remaining hot milk mixture, stirring constantly with a whisk. Cook over medium-low heat until the mixture covers the back of a spoon (about 4 minutes). Remove from heat. Add the blueberry mixture and let cool completely. Add the juice.Pour the mixture into the freezer compartment of the ice cream freezer; freeze according to the manufacturer's instructions.