I agree with the refrigeration. . . but...
I gotta tell people what the USDA/Calif. MFP rules say. Food Safety, always.
Yes, jams are preserved by 4 things: the acidity in a fruit, sugar (controls the availability of the water, cooking and the last method is by processing in a boiling water bath to seal. I recommend storing anything not processed, in the fridge though! smileys/wink.gif