@BReeder! It doesn't sound like a canning process issue - sounds like you did everything right. The jars must have been damaged or had a weak spot. It happens to the best of us.
Luckily, I have never had a jar break in the canner, but I remember my mom having jars break when making pickles when I was a kid.
I was canning some tomato sauce the other day and found a jar with a slight chip on the rim - external edge and was only about 1/4 of the thickness of the jar. I set it aside, but it turned out that I needed to use it for the last of that batch of tomato sauce. (it was clean, sanitized and hot - any other jars were down in the basement, dirty and cool). I marked the lid as chipped before I put the jar in the canner, so I would know which jar it was after I unloaded the jars. It sealed fine, but is sitting in my fridge to be the first jar used - just to make sure it stays good.
Luckily, I have never had a jar break in the canner, but I remember my mom having jars break when making pickles when I was a kid.
I was canning some tomato sauce the other day and found a jar with a slight chip on the rim - external edge and was only about 1/4 of the thickness of the jar. I set it aside, but it turned out that I needed to use it for the last of that batch of tomato sauce. (it was clean, sanitized and hot - any other jars were down in the basement, dirty and cool). I marked the lid as chipped before I put the jar in the canner, so I would know which jar it was after I unloaded the jars. It sealed fine, but is sitting in my fridge to be the first jar used - just to make sure it stays good.