Step 1

Pit plums; do not peel. Grind or finely chop. Measure 4 cups into a 6- or 8- quart sauce pot. Stir in walnuts, lemon peel and juice.

Step 2

Prepare jars (wash, inspect rims, clean in sink or dishwasher). Keep lids warm until ready to fill jars.

Step 3

Measure sugar and pectin into separate bowl.

Step 4

Bring fruit mixture to a full rolling boil on high heat, stirring constantly.

Step 5

Stir sugar/pectin mix into fruit mix in sauce pot. Return to full rolling roil and boil one minute, stirring constantly. Remove from heat.

Step 6

Gently stir in rum. Skim off any foam with a metal spoon, if desired. (I usually skip skimming.)

Step 7

Ladle quickly into prepared jars, filling to 1/4 inch of top. Wipe jar rims and threads. Cover with two piece lids.

Step 8

Process jars for 10 minutes in a boiling water bath canner. When processing time is done, let rest a few minutes in the water bath, then place jars on a towel on the kitchen counter. Allow to cool completely.

Step 9

Remove rings for storage. Wipe tops and test seals. Date and label and store in a cool, dark location. Best if used within 1-2 years.

Step 10

If any jars did not seal, refrigerate and use within a month.