Sugar

Pick and wash. Put in kettle and cook and stir as soon as you can for 1 1/2 hours until all plums are broken open, then stir the sugar in. If I got a 3/4 kettle full I add 2 quart jars of sugar and taste it. If not sweet enough, add more sugar so it tastes sweet then cook and stir for 20 to 30 minutes then shut off the stove. Leave set for 4 to 5 minutes then can it. Put a silver knife in the fruit jar as it is filled. Jar and can as fast as you can.