1. Can you use a normal pressure cooker or do you need one that is actually designed for canning?

2. Have you ever seen plastic disks that are somehow meant to be used for canning? I bought some a couple of years ago out of desperation when I couldn’t find proper canning jars - and then I finally did find the jars so the disks have been sitting in my cupboard ever since. I spoke with an elderly English lady about them briefly - but she seemed to think they were so basic I was embarrassed to ask for too many details. It seems like they are used by Europeans for re-using non-canning jars (yes, I know!). Anyway, just curious if you have ever come across them…?

Christy–the usual water bath canning is great for high acid foods such as fruits and pickles and for jellies and jams. And it used to be the preferred method for tomatoes as well.

However, the USDA tested the pH of tomatoes in the 1990’s and found that they had started being less acidic than they had been, so they recommended pressure canning instead of hot water bath canning.

Now–you can still can tomatoes in a hot water bath canner–but you need to add acid to them.

However, if you use a pressure canner for them, not only do you not need to add acid, you cook it for a shorter time at a higher temperature, so that vitamins and minerals tend to be preserved better.

Grace–it could be the age of the jars. After being used over and over, some of them will just go splewy and shatter.

You might need new jars….

I find it fun to can–though I do different stuff than Grandma did. She never made salsas, though she did make her own spaghetti sauces and can them. I will be doing some of that–I already processed about seven quarts of homemade marinara for the freezer, but I will probably do some canned too–it is just so convenient and tastes better than store bought.