Canning fail-what happened

There are a few reasons jars break - and it happens to even the most experienced canners.
For me, the most common reason is the jar has a hairline crack in it that I didn't see when I examined them. Fill it up, put it in the waterbath, it gets hot and kerflooey. That hairline crack gives way under the heat and yucky canner.

This doesn't sound like your issue but I will admit I have broken a jar one time early on - entirely my fault. Just wasn't thinking. I put cold'ish food in the jar, dropped the jar into the boiling water and knew instantly what I had done - SMH. Cold jar + hot water and boy did I feel silly.

I'm sorry it happened, but truly it happens to most of us at least once.

It can also happen if you put the jars directly on the bottom of a pan, instead of on a rack.

Lids may have been too tight when you put them in the canner too. I've done that before

I am sure it will not be the first time it will happen. I know it does happen to us all but it always sucks. If you do not have a rack or use a smaller pan I lay a tea towel in the bottom . Yes it floats and stuff but it does help.

The two most common jar failures I have seen happen are both bottom separation incidents..
Either the bottom separates in the canning process. Or separates when the seemingly sealed lid is taken off..

The most common brand of jar we have seen fail by breakage or lack of seal, is the Golden Harvest or other Walmart brand jar.. Rarely have we had a Mason, Kerr, Bernardin brand jar fail.. They can have damage like any other jar, but luckily few failures in our experience..

My jar was Kerr, I had a rack, the food was hot, i feel like the lid wasn't too tight... honestly it could have been a crack. My grandpa brought me some jars that were over 20 years old!