Grape Preserves Wouldn't Jell...

This is a recipe I've used in the past; it's scrumptious. My grapes are seedless so I don't have to follow the first few steps; I just cook them until soft and then add the orange peel and go from there.

The original recipe called for 1 1/2 lbs. of grapes to 2 1/2 cups of sugar, and I cut it down to one for one, which I'm almost certain I've done in the past. But this time it wouldn't thicken and we have to spread it with a spoon. Any ideas why?


Spicy Grape Preserves
2 lbs stemmed grapes

1 tbsp. grated orange peel

1 cup water
(I leave this out; squashing the grapes in the pot yields enough liquid)
2 cups sugar

½ teaspoon cinnamon

½ teaspoon cloves


½ tsp ginger

Wash grapes; separate skins from pulp. Cook pulp until soft; sieve to remove seeds. Add orange peel and water; cook 10 minutes. Add skins; heat to boiling. Add sugar and spices; cook till thick. Pour into hot, sterilized jars. Seal immediately. Or pour into hot, well-washed jars and store in refrigerator or freezer.
Makes about 4 cups.