Not sure whether this tip is helpful here. If one has a partially used jar - whether it is a cook-in sauce or a jam or almost anything either commercial or home-made, there is a way to re-seal it without it going off or becoming mouldy. Place the partially-used jar into the microwave and run for one minute on full power. Whilst doing this, wash the lid, rinse under running water and shake off to dry. Do NOT use a drying cloth as this could add contamination.. The moment the microwaving is done - as soon as the minute is up, hold the jar with a cloth to avoid burning your fingers and screw on the top. If it is the type of top with a safety button, you will hear that ping in, creating a partial vacuum up to about ten minutes later. By doing this, you are sterilising the top of the product and the air and it can be kept, not in a fridge, but in a cupboard and can be forgotten about until you next want to use it six months or a year later - it works and is safe every time. I've never had a recurrence of mould since using this technique. Chris.

I learned canning when I was a little girl with my Grandmother, & Mother and have taught my own girls how to can. We have been very successful with not havind unsealed jars. We have canned close to 100 25# boxes of tomatoes this year. Salsa, Stewed, Chili Sauce & Spag Sauce to name a few. We have followed the new rules to a T and still have several in a batch that do not seal with these new lids. We did 34 jars on Monday, waited the 24 hours before moving or washing them. Checked several times and found 5 that did not seal so I put new lids on and reprocessed them and they seemed to have sealed. When I went to wash the jars to store them, removing the rings found 2 more that had not sealed but I had previously checked the lids by touching and they were all sealed and indented. We want to make vegetable based soup to store for the winter but am afraid now to do it and put them on the shelf for fear the lids will pop and they will spoil. TRASH THESE NEW INVENTIONS AND GET BACK TO THE BASICS.

The Mason patent was for a threaded lid which could be used in conjunction with a threaded jar rim. It's generally a canning jar, but not necessarily. As you surmised, if the two-piece Ball or Kerr lids fit, there's no reason not to use it for boiling water bath, but pressure canning introduces stresses well beyond that. The only jars I would use for pressure canning are Ball and Kerr. Carol

No cookie jars in my house ! I would have to refill it every day if I had one around, too much temptation. I will occasionally buy ONE really good big cookie at a great bakery or store in my area with the intention of eating it later. I did that yesterday a big, warm delicious chocolate chip cookie , they bagged it up, I had it eaten before I even got to my car!!! No will power :(