Plum Jam (Without Pectin)

4.50 from 20 votes

Old-fashioned plum jam made with just plums and sugar, no added pectin. A small batch that gels on its own and cans up for the pantry.

Prep Time10

Cook Time30

Canning Time (Optional)10

Total Time50

Course: Canning

Cuisine: Preserves

Servings: servings, Makes 4 half pint (8 oz) Jars

Author: Ashley Adamant

Equipment

Water Bath Canner
Canning Funnel
Canning Jars, Lids, and Rings

Ingredients

9 cups plums chopped but not peeled
3 cups sugar

Instructions

Place the plums and sugar in a heavy-bottomed jam pot, ensuring that they fill it no more than halfway (the jam will foam up during cooking).
Turn the heat to high and bring the mixture to a boil, stirring frequently to avoid scorching (8-10 minutes).
Once the plum/sugar mixture is boiling hard, turn the heat down a bit to medium or medium-high to prevent scorching or overflows. Continue to stir frequently, and cook until the jam reaches gel stage. (That's 220 degrees when tested with an instant-read thermometer). It should take roughly 20 minutes at a boil, or 30 minutes total cook time, but can vary based on the fruit used.
Once it reaches gel stage, ladle the mixture into prepared jars. Store in the refrigerator for immediate use, or freezer for up to 6 months. Or water bath can for long term storage.

Optional Canning Instructions:

If canning, ladle the finished plum jam into canning jars, leaving 1/4 inch headspace. Cap with 2 part canning lids and process in a water bath canner for 10 minutes (pints & half pints). Adjust canning time to 15 minutes if above 6000 ft.
Properly canned jam in sealed jars should last for 12-18 months at room temperature in the pantry without losing quality. Once opened, store in the refrigerator and use within a few weeks.

Notes

Yield ~ This recipe makes about 4 half-pint jars (roughly 4 cups of finished jam). The recipe starts with 9 cups chopped plums, which is about 3 pounds prepared fruit or 3 1/2 pounds as purchased (with pits).

Altitude Adjustment ~ Process for 10 minutes at 0 to 6,000 feet and 15 minutes above 6,000 feet.

Doubling ~ Don't double this recipe. Larger batches take much longer to reach gel stage and often fail to set. Make two single batches back to back instead.

Low Sugar Plum Jam ~ You can cut the sugar in half for a tarter, lower-sugar jam. The yield drops and the cook time runs longer, but it still gels because the pectin comes from the skins. To go lower than half, switch to a low-sugar pectin like Pomona's.

Keep the Skins On ~ Plum skins carry most of the natural pectin and a lot of the flavor. Leaving them in is what lets this jam gel without a pectin packet. Dice the plums small if you'd rather not notice the skins in the finished jam.

A note on lemon juice ~ Lemon juice is optional here, for flavor only. Plums are high-acid, so no added lemon is needed for the jam to set or to can safely.

A note on variety ~ Plum variety changes the jam dramatically. Sweet purple plums make a classic jam, tart damsons cook into something dark and winey, and golden greengages turn out light and apricot-like.

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