Steps
- Combine 4 cups of frozen partridgeberries, 3 cups of peeled, cored, and chopped McIntosh apples, and 2 cups of sugar in a heavy saucepan.
- Simmer slowly over medium-low heat for about 45 minutes, until most liquid has evaporated and the jam is very thick. Stir often, then constantly near the end.
- Transfer to clean jars, cool, and refrigerate.