Bernardin Home Canning: Because You Can: Whole Grape Jam (Preserves)

Ingredients

• 2.8 lb (1.2 kg) Concord grapes, about 2 L
• Water
• 7-1/2 cups (1875 ml) granulated sugar
• 1/2 tsp (2 ml) butter or margarine, optional (to reduce foaming)
• 1 pouch (85 ml) BERNARDIN® Liquid Pectin