I’ve heard of this happening to other canners and after all these years . . it happened to me.
Yesterday I was canning 17 quarts of pinto beans for making refried beans. I had soaked them overnight, then drained them, got them all in the jars, added bacon and seasoning, got the canner started and they canned for 90 minutes. Once the pressure went down, I opened the canner and one of the lids had come off one of the jars. A whole quart of beans with bacon and bacon grease was all over the canner.
The three jars on the front right and the one behind the one on the very front right . . the ones that are not covered in beans and grease . . they were in a different canner. It was the biggest mess. I can’t lift the big canner when it has water in it so Vince took it outside, dumped it and scrubbed it clean.
I always tighten the jar rings before I pick them up off the counter because I pick them up by the ring/lid. I had to have just missed that lid but I’m not sure how but you can bet I won’t make that same mistake again.
The jar wasn’t broken . . the lid just unscrewed and came off. There were good beans in about the bottom third of the jar so I ate those with dinner last night. They were yummy and I’m happy I have 16 quarts . . but I’ll be sad about that 17th quart for a while.