Ingredients
1 11 1/2-ounce can frozen white grape juice concentrate
1 teaspoon freshly grated lemon zest (outside peel)
3 cups fresh or frozen blueberries
Directions
In a large saucepan, combine the grape juice concentrate, lemon zest and blueberries and bring to a boil over medium-high heat. Reduce the heat to medium and cook, stirring frequently to prevent the berries from sticking or burning until the mixture jells, about 25 minutes.
To test the consistency of the mixture, place a tablespoon of it in a small cup and cool to room temperature. Lightly touch the mixture to see if it has a jellied consistency. If it is still too liquid, cook for about 5 more minutes.
Remove from the heat, cover and set aside for 1 hour. Ladle the mixture into 2 sterilized pint jars. Cover and refrigerate for use. You can store the jam for about 1 month in the refrigerator.