iPlum Jam

1. Wash, pit, and chop the plums into 0.5-inch pieces; measure out about 8 cups of chopped fruit.

2. In a large nonreactive pot, combine the chopped fruit with granulated sugar and lemon juice; stir well, cover, and let stand 1 hour at room temperature (or refrigerate up to 8 hours) until juices are released.

3. Meanwhile, set a rack in a deep pot or canner, place clean jars on the rack, and fill with hot water to cover by 1–2 inches; bring to a simmer and keep jars hot. Wash lids and bands and prepare according to manufacturer instructions.

4. Bring the macerated mixture to a boil over medium-high heat, stirring often. Reduce to a brisk, steady boil and cook, stirring frequently and scraping the bottom, until thickened, 20–35 minutes; skim foam as needed.

5. Check doneness: the jam should register 220°F on a thermometer, or a spoonful on a chilled plate should wrinkle when pushed at the edge.

6. Working one jar at a time, remove a hot jar, ladle hot jam into the jar leaving 0.25 inch headspace, and wipe the rim clean. Center a lid on the jar and screw the band on until fingertip-tight.

7. Return filled jars to the canner, ensuring they are covered by 1–2 inches of boiling water. Cover and process 10 minutes (start timing when the water returns to a full boil; increase time as needed for altitude).

8. Turn off heat and let jars rest in the hot water 5 minutes, then transfer to a towel-lined surface. Cool 12–24 hours undisturbed.

9. Check seals (lids should be concave and not flex when pressed). Label and store sealed jars in a cool, dark place for up to 1 year; refrigerate any unsealed jars and use within 3 weeks.