ottawa foodies

This is awesome! I've had it happen a few times but my buddy Nick (Halifax's Nomad Gourment food truck) captured it on video

This is very neat but I don't understand why they popped more than once. I've seen and heard my preserves pop down as they cool on the counter but have never seen nor heard them pop back up and then down again several times.

Something as simple as a small air current going over top will do it. As the jars cool to just the popping point it can do this because a current will momentarily bring it to pop in, but then the internal temperature makes it pop back out. Sort of the same idea as why when I took a plastic container of juice in from the side porch 2 days ago it was not frozen but as soon as I opened it, it froze up right before my eyes in about 30 seconds. Wish I'd gotten that on video. I opened a 2nd one to try it but for some reason that one did not freeze up. But it was basically at just the right temperature .

Although I think it basically means they were taken out of the canner too soon. These days I like to leave mine in til well beyond the popping point.