This is a soft jam filled with the sweetness of peaches and plums without being overly sweet. Enjoy.
Variation on a Theme: While boiling fruit place a cheesecloth bag filled with 5 crushed cinnamon sticks, 5 allspice berries and 10 whole cloves to created a spiced peach plum jam for the holidays. Make sure you remove the bag before filling jars.
Prepare waterbath canner by placing clean jars on rack and fill pot and jars with hot water till it just barely covers the jars, then bring to a boil. Once the water begins to boil turn temperature down to simmer and drop in rings and lids.
Chop peaches and plums.
In an 8 large pot combine chopped peaches, plums and juice or water. Gradually stir in pectin. Bring mixture to a full rolling boil that can not be stirred down, over high heat, stirring constantly.
Add sugar. Boil hard for 1 minute stirring constantly. Remove from heat. Skim foam if necessary.
Remove jars from canner and empty out water. Place jars on a folded towel.
Ladle hot jam into hot jars, one at a time leaving 1/4 inch headspace. Wipe rims. Center lids on jars. Apply bands and adjust to fingertip tight.
Place filled jars in canner making sure jars are covered by at least 1 to 2 inches of water. Place lid on canner. Bring to water to gentle, steady boil. Process for 10 minutes. Turn off heat and let set for an additional 5 minutes.
Remove jars and place on a folded towel and let cool undisturbed for 24 hours. Check to see if lids are popped down before storing. If they aren't store in fridge.