I made peach jam yesterday. It was 98 degrees and disgustingly humid so I figured that would be the perfect day to have vats of boiling jam and water on the stove!
When I took my filled jars out of the boiling water, all of the lids "popped" shut within a minute except one. I waited about 1/2 hour and it still hadn't popped so I tossed it in the fridge figuring I would just use it right away. However, when I went back to check it, a couple of hours later, the lid had popped and appeared to be sealed tight. Do you think this jar is now shelf stable or was it somehow just related to the temp change and it's not really sealed?