Plum-Ginger Freezer Jam
This no-cook jam captures the joy of biting into a cold, crisp plum, and the technique it employs is ideal for capturing the freshness of firm ripe summer fruit. This jam, which can be stored in the refrigerator or freezer, making it what's commonly known as a refrigerator or freezer jam, is also packed with ginger and lemon, so you’ll get a bouquet of flavors in every spoonful.
- Serves: 6 persons
- 3pounds ripe but firm plums, pitted and cut into 1-inch pieces (about 5 cups)
- 1cup superfine sugar
- 2tablespoons scrubbed, grated fresh ginger
- 2tablespoons lemon zest (from 4 lemons)
- 2tablespoons lemon juice, plus more to taste
- ¼teaspoon calcium powder, if needed (see Tip)
- 4 ½teaspoons powdered pectin (see Tip)
- ½teaspoon kosher salt (Diamond Crystal)
Step 1Using a potato masher or fork, gently crush the plums in a large bowl to release some pulp and juices while keeping the fruit chunky. Toss with the sugar, then add the ginger and lemon zest and juice. Stir until the sugar dissolves. Measure the volume of your fruit mixture; you should have about 6 cups.
Step 2If your package of pectin comes with calcium powder, stir 1/4 teaspoon of the calcium powder into 1/4 cup water to dissolve. Set aside. Place the 4 1/2 teaspoons pectin in a stand blender, or have it measured and ready if using an immersion blender. Bring 1 cup water to a boil, then pour it into the stand blender and blend. (If using an immersion blender, add the pectin to the saucepan and blend.) The mixture should become very smooth and look like a soft gel. Stir the pectin mixture into the fruit until evenly combined, then stir in 4 teaspoons of the calcium water, if using. The jam should thicken and be softly set. Add the salt, stir and taste. Adjust after tasting with more teaspoons of lemon juice, if necessary, for a good balance of sweet and tart.
Step 3Transfer to clean airtight containers, cover and chill in the refrigerator for at least 24 hours and up to 2 weeks before serving. Or, store in the freezer for up to 3 months; defrost completely in the refrigerator before serving.