In farm life, there is always something happening to keep you humble.
I'm not new to canning, but last week I experienced something that had never happened before. When I opened my water bath canner to remove seven jars of fabulous dill pickles...three jars were floating.
Floating jars? What does that mean?
Upon carefully removing the jars, I discovered I had a mess on my hands. For I had one...
Ā
Ā
Ā two....
Ā
Ā and three jars....
Ā 
whose bottoms all popped off while in the canner.
I just stared into the bowl. Broken jars, and wasted pickles. That's enough to make a farmgirl mad!
I asked around to my farmgirl friends who informed me there are many reasons that jars can break in the canner, but it is most often because a) a cooled off jar was put into a canner that was too hot, b) a hot jar was put into canning water that was too cold, or c) the jar was already cracked or weak when put into the canner.
Well, darn it. Live and learn. Farm life keeps you humble, for sure! I know they say there is no point in crying over spilled milk, but I do think shedding a tear over wasted pickles is probably acceptable. :)
How disappointing, Amy! Sometimes jars have a flaw and they just break, and other times it's what your friends mentioned about hot/cold, cold/hot.
I had that happen with one jar of peach jam several years ago. It was a spanky new jar into cold water, and not the first cold packing of that batch either, so I doubt it was temperature shock. I chalked it up to not being on the family shopping trip that acquired the jars in the first place. I had told them what to get, but they decided to save money (a dollar or two at most!) and bought a cheaper flat. So I am figuring a flaw in the glass is what did it in. I just count myself as lucky that it cracked around instead of bursting, which would have broken more jars in the batch.
I have been doing a lot of canning here recently. I had some brand new jars break on me while I was canning some beef stew. I cold packed everything and had cold water in the canner. I totally believe that some jars are just weak from the get go. I have had some previously used jars do the same thing and I understood that but brand new... I was in shock. I'm glad you posted this because I now know it was just weak jars!
Amy, I had one of my jars of tomatoes that did the same thing. I didn't do anything different from the other times I water bathed canned them but one out of four broke. Another one didn't seal. I have never had either of these issues in the past. Who knows what the issue was. Have a great canning day.