Prune Plum Jam Recipe

Wash, peel, pit and chop plums. Combined plums, plum juice, and pectin into a medium saucepan, mix well. Add butter and bring to a boil over high heat, stirring continually. Add sugar all at once and bring back to a hard boil, stirring until sugar is completely dissolved. Boil hard for (1) minute. Ladle into very hot sterilized jars leaving 1/4" head space. Wipe rims and threads with a clean damp cloth. Tighten rings and lids. Place on a towel and let stand over night to cool. Check seals and store in a cool dry place. Shelf life is one year and, refrigerator life is six months.