One of my favorite summer fruits is also one of the most fleeting—plums. Smaller and denser than peaches, more meaty than juicy, with as many sour notes as sweet, plums are delicious on their own, but they really sing when they’re cooked.
How do you preserve plums without losing their rich flavorful essence? Make jam, of course. Read our complete guide to stone fruits before you start.
How to Make Plum Jam
- 10 cups chopped plums* (about 4-1/2 pounds)
- 1 cup orange juice
- 1 package (1-3/4 ounces) pectin for lower sugar recipes
- 3 cups sugar
- 3 tablespoons grated orange zest
- 1-1/2 teaspoons ground cinnamon
*Do you peel plums for jam? You don’t have to. When the plums are cooked, the skins will soften and add flavor and color to the jam. They will be slightly chewy, though, so you may peel the plums if you choose, or blend the jam with an immersion blender before canning.
Step 1: Cook the plums
Put the plums and the orange juice into a Dutch oven or other large, heavy-bottomed pot. Bring the mixture to a boil, then reduce the heat and cook until the plums soften, about 5-7 minutes.
Step 2: Add pectin
Add the pectin to the pot and return to a rolling boil for one minute, stirring constantly. The added pectin will help the jam set properly.
Step 3: Add the rest of the ingredients
With the pot boiling, add the sugar, orange zest and cinnamon. Bring back to a boil if necessary and cook, still stirring, for one minute.
Step 4: Transfer into jars and can
Remove the pot from the heat. Some foam or froth may have risen to the surface; skim it off with a spoon and discard. Ladle the jam into sterilized half-pint jars, leaving 1/4-inch headspace. Make sure to remove air bubbles in the jar by carefully inserting a clean spoon or knife into the jam and gently pushing against the side of the jar. Wipe the rim of the jar clean before topping with a lid.
Step 5: Sterilize and seal in a hot water bath
Carefully lower the jars into a simmering water bath, making sure they’re completely submerged. Bring the water to a boil and let the cans sit for 5 minutes. Then remove from heat to a cool, dry place. Over the next few minutes, you may hear the pinging noise of the cans sealing. After 24 hours, check that the jars have sealed, and store in your pantry for up to a year. If any jar failed to seal, keep it in the fridge and eat immediately.
Can Plums Be Frozen?
Yes! You can freeze plums. Just wash them, slice in half and remove the pit, then freeze on a baking sheet in a single layer. When frozen, store in a tightly sealed bag. Note that the texture of a frozen plum won’t be the same as a fresh plum, but the fruit can still be used to make jam.