Plum & Apple Jam

5 lbs plums, pitted and sliced (14-15 cups)
3 Granny Smith apples, peeled, cored, and sliced
¼ cup white grape juice (or your favorite fruit juice)
2 tbsp lemon juice
¾ cup sugar
¼ tsp ground cinnamon or ginger

1. Place a plate in the freezer to test consistency later.
2. Combine plums, apples, grape juice, and lemon juice in a large pot. Bring to a gentle boil over medium-high heat and cover, stirring occasionally for 15-20 min until fruit is softened.
3. Uncover and boil gently for another 20 min, continuing to stir.
4. Reduce heat to medium and add sugar and cinnamon/ginger. Cook and stir frequently for about 15 min longer, until a spoonful of jam dropped onto the chilled plate holds its shape.

Spread jam onto bread or muffins, or spoon over a bowl of oatmeal or yogurt.