Hi Carol, I have never used Goverener Plums (never had it available anywhere). I have a regular Plum Jam recipe here http://chefinyou.com/2009/02/plum-jam-and-canning-jam-101/ which uses honey instead of sugar. Try that recipe - may be it might work. Your notes would be welcome since it might help others who are using these plum varieties. :) -- DK
The questions are always welcome jennifer :) Sorry for skipping out on the honey in the steps. Have updated the same - it needs to be added along with the plums and raisins. Actually the sweetness is dependent on the fruit itself. Mine were not exceptionally sweet and somehow the honey and sugar dint make it too sweet either. You can of course reduce the sugar to 1/2 cup in the recipe if your plums are v sweet. The jam does not get affected by it though. I have also tried it without using sugar and using only honey instead - it still comes out pretty well..
Refrigerating def. helps to prolong the life of the jam even for home made jams. Since I have always refrigerated, I dont have the exp. to tell you what would work here :( . I looked around the net for some info regarding this - see if this link helps to answer your query : http://www.uga.edu/nchfp/how/can_07/storing_jams.html