Combine all ingredients (except start with about half the amount of juice and add only as necessary to to achieved desired consistency) in the canister of a blender and blend until smooth and creamy. Blueberries take awhile to break down, so you may need to blend for a couple minutes.
Serve immediately. Extra portions may be frozen in freezer-safe (plastic) glasses for up to 3 months. Allow to soften at room temp before serving.
