It's been awhile since I shared a canning recipe! This is a plum jam that I made this fall.
Begin with about 8 cups pitted and peeled plums. Put them in a large saucepan with a half cup water and bring to a boil. Reduce the heat and boil gently until the plums are softened, about 5 minutes.
You can crush the plums but I wanted something a little more consistent so I pureed them with my stick blender. This gives you about 6 cups of pulp.
Now add 1 package of (1.75 oz) regular powdered fruit pectin and whisk it in really well. Bring the mixture to a boil over high heat, stirring frequently.
Add 8 cups of granulated sugar all at once and return to a full rolling boil, stirring constantly. Boil hard, stirring constantly, for 1 minute. Remove from heat and skim off foam.
Prepare your jars and lids. See HERE for further information of preparing your jars and lids.
Ladle hot jam into the hot jars, leaving 1/4" headspace. Remove any air bubbles and add more jam, if needed. Clean the rims with a damp towel and put on the lids. Screw band down until finger-tip tight.
Place your jars in a water-canner, making sure they are completely covered with water. Bring to a boil and process for 10 minutes. Remove canner lid. Wait 5 minutes, then remove jars, cool and store.