Plum Jam Step by Step
Step 1:
Remove the heft from the plums and divide into quarters. If you are using a loose stone variety of plum, cut around the equator, twist in half to separate them, and discard the pit. But with clingstone varieties, such as these Elephant Heart plums, it is easiest to cut out the pit with a knife. If you cut away five pounds of plums, you should be left with four pounds of plum pulp. This is because much of the plum’s aroma is in the skin!
Step 2:
Maceration Transfer the plums and chopping liquid to a large bowl (the largest one you have) and add 1 1/2 pounds of granulated sugar and 1 tablespoon of pectin for every 4 pounds of plums. Stir in the plums, cover with plastic wrap, and refrigerate overnight until the juices run clear.
Step 3:
Start cooking Place plums in a saucepan and add 4 teaspoons calcium water. (The proper dilution rate for the calcium water can be found on the pectin package.) Place the pot over medium heat and bring to a simmer. Stir frequently while simmering to prevent the bottom of the jam from burning.
Step 4:
Crush the plums. Once the plums have broken down a bit, they should be soft enough to crush. Running the jam through a food mill will break up the plums and produce a smoother textured jam.
Step 5:
Simmer down As the jam simmers, bubbly scum will appear on the surface. Remove this scum if you want the jam to be glossy. Adding a small amount of butter to the pan will help reduce the foaminess.
Step 6:
Test for doneness Once the jam has thickened and become glossy (takes about 15 to 30 minutes), it’s time to check the baking. Place a small amount on a frozen spoon and return to the freezer. Let rest for 5 minutes and check the jam. It should be firm but not rubbery and stick to the spoon when tilted. At this stage, it is almost done. The jam can be chilled and stored in the refrigerator and eaten within a few weeks, or it can be jarred and stored at room temperature for several months.
