Greetings Charles C.. The editing of the title may be off. I think Dakis is talking about the storage of raw materials (fruits and vegetables) that are used in the production of jam and not jam itself.
Due to its high sugar content the only microorganism that could be affecting the end product and can derive from the raw materials could be molds (not even yeasts). But then again cold storage will only put the mold in hibernation (spore formation mode on !!!), so still not really a CCP. And the jam is made by peeling the fruits etc so there is a really really minimal chance for the inside to have been affected by molds.
The real CCP would be the pasteurization.
My opinion is that raw materials storage is OPrP or CP. You do need some control over it to prevent molds from growing uncontrollably (lets not have a Last of Us incident! - no attempt at advertising here) or enymatic blackening (which deteriorates flavor, smell, appearance), but not so strict.
I do have to say that if the mentioned scenario about fridge breaking down becomes real, then you would have to test for mycotoxins if there is a visible high growth of molds. That's when they may start producing toxins, most of which by the way are destroyed in high temperatures, but do it anyway just to be safe.
By visible high growth I mean that you can actually see the hyphae.
As a sidenote, not home-made jam has to be shelf-stable in ambient temperature. I have never seen large scale production jam being stored in cold conditions during selling (some excemptions may apply of course).