Homemade Blackberry Plum Jam

Recipe by roozoo
READY IN: 45mins


  • 3
    cups plums, chopped and pitted (leave the skins on)
  • 3
    cups blackberries, crushed (do not puree, crush with potato masher)
  • 6
    cups sugar (add less if desired)
  • 1
    (1 3/4 ounce) package dry pectin (Sure Jell works well too)


  • Prepare the boiling water canner before starting to cook your jam. (Fill the canner/stockpot at least half full of enough clean, warm water so the level will be at least 1" over the top of the filled jars once they're added).
  • Wash, pit and chop plums w/ skins.
  • Wash and crush blackberries w/ potato masher.
  • Place plums and crushed blackberries in large pot.
  • Add pectin a little at a time to plums and berries, stirring constantly.
  • Heat on high stirring constantly until mixture comes to a FULL boil.
  • Add sugar ALL at once, stirring.
  • Bring mixture back to a full hard boil, stirring constantly.
  • Use potato masher to carefully further crush plums and berries in pot.
  • Boil for 5 minutes.
  • Skim off foam, if present.
  • Place in sterilized, hot jars, leaving 1/4" headspace.
  • Wipe edges of jars with clean cloth, place lids and screw on bands fingertip-tight.
  • Process in a boiling water bath for ten minutes at sea level (over 1000 feet, add one minute of processing for each 1000 feet in altitude).
  • Remove from water and place jars on a cloth-protected counter or cooling rack to cool undisturbed for 24 hours.
  • Remove rings from sealed jars and store; put any unsealed jars in the refrigerator and use first.