Start by preparing jars and getting water in the canner heating.You want the canner hot, but not boiling, when the jars are ready to be processed. See full water bath canning instructions here.
For a Hot Pack
Make a light or medium syrup.
Wash fruit and prick each plum skin.
If desired, slice plums into halves, removing pits.
Place your plums in syrup or water.
Bring to a boil for 2 minutes.
Cover and let this rest for 20 to 30 minutes.
Gently pack plums in jar.
Cover with syrup or cooking liquid, leaving 1/2” headspace.
Remove air bubbles. Wipe the rim clean and place on your seal and ring.
Place the jar in the warm canner. Proceed to fill all jars. Process according to the chart below.
For a Raw Pack
Make a light or medium syrup.
Wash fruit and prick each plum skin.
If desired, slice plums into halves, removing pits.
Gently pack raw plums in jar.
Cover with syrup, leaving 1/2” headspace.
Remove air bubbles.
Wipe the rim clean and place on your seal and ring.
Place the jar in the warm canner. Proceed to fill all jars. Process according to the chart below.
Notes
Processing with a Water Bath CannerPlace the jar in the warm canner. Proceed to fill all jars placing them in the canner.When all the jars are filled, bring the water in the canner to a boil. When a boil is reached that is when you'll start your timing. Process for the length of time on the chart below. Adjust for your altitude. After your time is over, turn the heat off remove the lid and allow the canner to rest for about 5 minutes. Then bring your jars up out of the water. Allow them to rest for another 5 minutes. Then remove the jars and place them a few inches apart on a thick towel to cool completely. Leave them alone for about 12 hours. When they are cooled remove the metal bands, check the seals, label the jars and store them away! Processing Time for Pints in Water Bath (Raw pack or Hot Pack)
0-1,000 ft - 20 minutes
1,001-3,000 ft - 25 minutes
3,001-6,000 ft - 30 minutes
Above 6,000 ft - 35 minutes
Processing Time for Quarts in Water Bath (Raw Pack or Hot Pack)
0-1,000 ft - 25 minutes
1,001-3,000 ft - 30 minutes
3,001-6,000 ft - 35 minutes
Above 6,000 ft - 40 minutes
Source: The National Center for Home Food Preservation