I recently had a complaint from someone that said that a pear based jam that I made separated and that after they looked it up on the internet they realized it was botulism! Ugh! Is all I could think and I got pissed. I think my only pet peeve when it comes to giving away jams and jellies is when people make off the cuff comments that are neither constructive nor polite.
I go through great lengths to make sure that the product that I produce are safe including following precautions for seal failure which means that I don’t give out the product for 2 weeks while I observe the products without the band ring to make sure that the seal is good.
With this said seal failures will occur and other odd things will happen especially if my instructions are not followed regarding storage. These items will technically last years if kept in a cool, dry, dark space! With this said separation does occur it is not the end of the world it just means that there was more air in the fruit and it rises to the top in the jam. If this happens let me know. I just means that I need to tweak my recipe and cut the fruit smaller or cook much longer.
Here is a link that discusses this if it happens to you. http://foodinjars.com/2015/06/canning-101-how-to-prevent-jam-separation/#comments