Then, a few months later you'll get a renewed craving, this time for PB&J rugelach perhaps, and you might wonder: Is that ...

Ok, here's the thing. I grabbed a jar of grape jelly to make a sandwich just now and twisted hard, but it didn't budge. Let go of the top, grabbed it again, and it turned easily.

Take a look at the ingredients of most jelly jars, and it's a pretty simple list: fruit, pectin, some sort of sweetener, and some form of preservative (like citric acid or sodium citrate).

Prepare jelly jars and rings by either sterilizing them, which will shorten the processing time, or by washing them thoroughly in hot, soapy water and then rinsing well. Place jars and lids in a ...