Homemade Blackberry Plum Jam Recipes

Steps:

• Place the plums and water into a large pot, and bring to a boil. Reduce heat to medium-low, cover, and simmer for 5 minutes. Stir in the sugar, and add butter to reduce foaming, if needed. Bring the mixture to a full, rolling boil over high heat, stirring constantly, and then mix in the pectin quickly. Return the jam to a full boil, and boil for 1 minute, stirring constantly. Remove from heat, and skim off and discard any foam.
• Sterilize the jars and lids in boiling water for at least 5 minutes. Pack the plum jam into the hot, sterilized jars, filling the jars to within 1/8 inch of the top. Run a knife or a thin spatula around the insides of the jars after they have been filled to remove any air bubbles. Wipe the rims of the jars with a moist paper towel to remove any food residue. Top with lids, and screw on rings.
• Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil over high heat, then carefully lower the jars into the pot using a holder. Leave a 2 inch space between the jars. Pour in more boiling water if necessary until the water level is at least 1 inch above the tops of the jars. Bring the water to a full boil, cover the pot, and process for 10 minutes.
• Remove the jars from the stockpot and place onto a cloth-covered or wood surface, several inches apart, until cool. Once cool, press the top of each lid with a finger, ensuring that the seal is tight (lid does not move up or down at all). Store in a cool, dark area. Refrigerate opened jars for up to 3 weeks.

Steps:

• 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.