The plum’s high amount of pectin brings joy to any canner. In fact, plum jam requires no added pectin. This recipe uses just 3 simple ingredients.
4lbs.peeledseeded, and crushed plums (crushing helps with the seeding)
Sterilize jars and setup canning equipment.
Combine ingredients into a large saucepan and bring to a boil, stirring frequently to dissolve sugar.
Once a boil is reached, reduce temperature to medium-high and continue to stir frequently to prevent burning.
Reduce syrup until the jelly stage is reached. (The spoon test and the freezer test work well, but since I know there is enough pectin, reading the temperature is the easiest method for me. The syrup should read 8° above boiling point, 220° at sea level. Be careful not to get the temperature too high, 223° is the thread stage in candy making! Invest in a good thermometer; you’ll be glad you did.)
Fill jars to ¼ inch from the top and boil in a hot water canner for 5 minutes (10 minutes above 1000 feet, 15 minutes above 6000 feet).