Hi,
Canning 911, several anecdotes from one person:
Crisis 1:
Saturday evening at 8:45 pm, I get an unhappy phone call from a friend. "All my jars are exploding. I'm losing a day's work. I am not coming the picnic tomorrow." As she was lifting jars of tomatoes from the water, they were breaking. When she called, there were three busted jars and several more sitting in the pot.
I had just provided this person 36 canning jars bought for $9 at a rummage sale. Some were brand spanking new with new lids and rings. A casual inspection suggested they were fine. My friend was sure it was the jars.
I learned from being a Master Gardner volunteer, you need to ask a lot of questions to find out what really happened. It took a while to figure out what was happening here. Instead of water bath canner and rack, she used a stock pot. This is fine, if you make some adjustments. Apparently nothing came between the jars and bottom of the pot, which is a great opportunity for thermal shock. A towel or improvised rack at the bottom would have helped here.
I then asked, "Were the jars touching each other?" "Yes, I do this all the time." I said those jars banging against each other was a likely source for cracks. "I do it all the time!" "You were lucky those other times. Today you're luck ran out."
If she had spaced the jars and used a towel, while not ideal, it is workable. When I was a Master Food Preserver volunteer, this was a suggested method for someone who could not afford a waterbath canner. It is also adequate for someone who is testing this out.
Crisis 2:
Yesterday morning, I received a phone call advising, "My stove just blew up." When she switched on a burner to make breakfast, two rings of fire began at the stove and floated to the ceiling. I will admit that is not how I would want to start my day, too.
She had finished two gallons of sauce the evening before, which now needed canning.
After waiting for a service call and learning the stove won't be back in action until October, my friend and her sauce were at my house.
While waiting, she had used her gas grill's side burner to reheat the sauce and get them jarred. By the time they reached my house, they were nearly back to room temperature.
Much to her chagrin, I emptied all the jars, reheated the contents, jarred and processed them. If I could have found anything to suggest you could properly process from room temperature, I would have though I didn't.
I ran into an issue with my pressure canner, which I quietly took care of without much comment. I figured if I said something, it just would be another source of frustration. My pressure canner simply didn't come to pressure. It made funny noises, I observed water leaking through a seal on the rim and decided nothing was going to happen here.
I turned off the burner to depressurize and inspect the gasket. It depressurized quickly, because it was never under pressure. I looked the seal over, took a towel and wiped. At 9:15 PM, the chance I could quickly buy a new gasket was zero. What the heck, I closed the pot and began reheating. After it evacuated steam, I put the weights back on and it sealed fairly quickly.
I think I have been given my warning this gasket may be wearing out. I'll get a new one by next year. I already have most stuff I would pressure canned out of the way.
Just before 1 am, we were finished processing. I did get to watch two movies: Young Victoria and a 9/11 film by Oliver Stone.
Regards,