Blueberry Refrigerator Jam
["1 1/2 tsp. unflavored gelatin", "1/3 c. frozen sweetened grape juice concentrate, thawed and undiluted", "3 c. fresh blueberries"]
["Sprinkle gelatin over grape juice concentrate in a saucepan. Let stand 1 minute.", "Add blueberries and cook over low heat, stirring constantly, until gelatin dissolves and mixture thickens slightly.", "Cool.", "Pour preserves into airtight containers and chill until set.", "Store in refrigerator."]
["unflavored gelatin", "frozen sweetened grape juice concentrate", "fresh blueberries"]