It is called thermal shock breakage. The water in the pot was far hotter than the temperature of the jars going into it.

So if the jars were hot as they are supposed to be and filled with hot contents as are supposed to be then the water in the canner was far too hot. It isn't supposed to be boiling. Just hot, max. of 180 degrees.

It often happens when folks let the filled jars sit on the counter cooling as they fill the remain jars.

Sorry for the mess.

Dave

There are several kinds of breakage you might experience in canning jars. (If you can lots or over a long period it's likely you'll see all of them at one time or another.)

As Dave said, thermal shock is identified by a crack that runs around the lower portion of the jar and sometimes up the side (the bottom falls out).

A vertical crack that runs up the side and may "fork" is an internal pressure break. That's caused by inadequate headspace, sudden changes of temperature in a PC (forced cooling by running water over the top of the canner or removing the weight before pressure reaches zero).

Impact breaks look like a windshield does when a rock hits it. I think of this one everytime someone returns canning jars clanking around in a plastic bag. It also can happen if a jar is damaged by a metal knife used to remove air bubbles or just the wear-and-tear of age such as scratching or rubbing.

Carol

I think the "thermal shock" was the problem, because I did not have the contents hot enough when putting in the water bath. I had a "check" in this before I did it, but followed a website that OK'd the procedure of just adding hot juice or water to the cold cut up tomatoes in the jar. Next time, to make sure I think I will heat the tomatoes to the boiling point BEFORE putting them in the jars.

Also, how do you test to make SURE you have a good seal when taking them out? Shouldn't there be a sound of the lids sealing? A little "ping"?

~Barb

but followed a website that OK'd the procedure of just adding hot juice or water

Big no-no. All the approved tomato canning instructions call for boiling liquids - even the raw pack instructions.

Jar may seal in the canner, immediately on removal or even 10-20 mins. later. So while the ping/thunk is nice to hear you don't always hear it. A true seal is determined by the concave shape and firmness of the lid center when you check them several hours later. Then once you remove the rings you can test the seal the next day by carefully lifting the jar by the lid.

Dave

This is good info Dave. I think I really messed up this time. It has been several years since I canned. What sounded like an easy and feasible job I believe has cost me this batch. I checked for that concave center, and don't believe it's there. I'll know better next time. I'm trying not to get depressed, lol!

You sound like a pro :)It's so nice to see people willing to help out others on this forum.

Thanks again,

Barb

You can re-process the tomatoes with clean jars and new lids as long as it's within 24 hours. That way you've lost some time but not the product.

They'll be a little softer but still perfectly fine for soups or other cooked recipes.

Basically with a jar that's sealed you don't have a "bouncy" lid. It's solidly concave without spring. But often you don't hear anything, either because the jar's already sealed, as Dave mentioned, or because there's product against the lid, dulling the sound.

Carol