Last year, I found that one of my most appreciated preserve was pie filling. I had resisted making pie filling, because I am really, really fussy about fillings thickened with tapioca, too much flour or gels. I prefer my fruit natural and intensified by simple reduction and seasoning, not artificial thickeners.

Liana Krissoff seems to share my feelings about this. She says, “Official recipes for canned pie fillings consist of sliced fruit in a syrup thickened with something called ClearJel, which is cornstarch that has been specially engineered to remain stable when heated during processing – other starches break down and lose their thickening power in the canning pot.  I’m sure those pie fillings are just fine, but when putting up stone fruit or muscadines or Concord grapes to be used in pies (or cobblers) I prefer to more closely replicate what one does when making a pie from scratch, so that the juices being thickened are the fruit’s own rather than plain water plus lots of modified cornstarch. I simple add the thickener – instant tapioca, a little flour, or regular cornstarch – when I open the quart jar of fruit to make the pie.”
This recipe can be either processed in jars or frozen in quart sized freezer bags.
6 lbs plums, pitted and cut into eights (12 generous cups)
3 TBS strained fresh lemon juice (bottled is fine too)
3 cups sugar
1 1/2 tsp ground cinnamon
2 generous pinches ground clove
Put the plums, lemon juice and 2 cups of the sugar in a large bowl.  Toss gently to combine.  Let stand at room temperature for about 1 hour, until the plum juices are almost deep enough to cover the plums.
Working in batches if necessary, drain the plums in a colander set over a nonreactive pot.  Return the plums to the bowl and toss with the remaining 1 cup of sugar (or more to taste), the cinnamon and cloves.
You can either stop here, put 4 generous cups into a freezer bag and freeze, or go on to prepare for water-bath canning.
Wash the jars and keep them hot in the canning pot, and put the flat lids in a heatproof bowl.
Bring the plum syrup to a boil.
Ladle boiling water from the canning pot into the bowl with the lids. Using a jar lifter, remove the hot jars from the canning pot, carefully pouring the water from each one back into the pot, and place them upright on a folded towel.  Drain the water off the jar lids.
Pack the plums into the jar, leaving 1 1/2 inches headspace at the top.  Ladle the hot syrup into the jars, leaving 1/2 inch headspace.  Use a knife or chopstick to remove air bubbles around the inside of each jar.  Use a damp paper towel to wipe the rims of the jars, then drain the water off the jar lids and put a flat lid and ring on each jar, adjusting the ring so it’s just finger-tight.
Return the jars to the water in the canning pot, making sure the water covers the jars by at least 1 inch.
Bring to a boil, and boil for 25 minutes to process.  Remove the jars to a wire rack or folded towel and do not disturb for at least 12 hours.
Before storing in your pantry, check to be sure jars have sealed by unscrewing rings and lifting jar by the cap. A properly sealed lid will stay firmly sealed and may be stored for at least 6 months (I tend to push the envelope on this one and have enjoyed canned goods well into their second year).
If the jar has not sealed, it should be refrigerated and used quickly.