I had bought a box of jars at walmart, the mainstay brand, I liked that they were plain and smooth, easy labeling. I was canning sweet pickle relish and zucchini relish and decided to use these mainstay half pint jars. I thought when I open the lids they were a little odd. Even the rubber on them were different textured. I water bath the relish as I have always done before. 12 of them. none of them sealed. in all the years I have been canning I have never had this happen. I had to remove the lids, put new ones on and reprocess. Did not use the same brand the second time. Today my niece and I were canning green beans, I was one lid short, I inadvertently opened the mainstay box of lids and used one out of it. we processed the beans. when we opened the canner there was this jar of beans with a crease in the side of the lid like it had buckled and the top swollen like it was about to explode. I fear that if the time was any longer then the 20 min required for processing the beans, it would have exploded. So please keep in mind what you are buying. And remember, cheaper is not always better.
Interesting events. Unfortunately I've never had such problems with any lids over the years so I can't relate, but if there is evidence of a defective lid you should contact the manufacturer and return them for testing. The construction of flat lids are rather basic and not much can go wrong with them. I've even used flats acquired from estate sales and had to be 20+ years old and none failed.
I would examine your canning procedures and make sure you are following the current procedures correctly, including the longer delay before removing the canner lid and avoidance of drafts. There can be many reasons for lids not properly sealing. A bent/warped lid is usually evidence of a catastrophic purge by the spring lid being on too tight (they should be only finger-tight).
Just canned green beans with the mainstay brand lids. Three of the four jars, the lids creased. This is the second time this has happened to me while using the mainstay brand. The first time I was teaching my daughter and her boyfriend how to can, and thought it was due to the rings being to tight...Wrong!!!! Have not had a problem with this brand using water bath method, just a problem with pressure cooking. GRRRR!
Why do you say that its not from the rings not being on too tight? That and exposure of the jars to a sudden temperature change at some time during processing. You can blame the flat lids all you want but they aren't the problem.
Although I do not wish to debate the point on mainstay brand lids. I have been canning for 40 years...in that time I have NEVER had a lid crease on me. After examining the lids that creased, there seems to be a slight defect on the edges of some of these lids. I will be contacting the company, and sending them these creased lids.
So yes, I do believe it is the result of poor quality lids.
A good way to prove it to the company is to place several flats in your pressure canner without attaching to any jars and run the canner through it paces. If you are right the lids should warp on their own. That would prove there is nothing else involved causing the flats to become twisted.
I assume you have been updating your canning knowledge as changes have been made, especially after the 1990's, such as waiting 15 minutes after pressure drops to zero and the vent is opened before removing the lid.
I had the same problem with those lids!! returned all I had. I have been canning for over 40 yrs and keep up to date on canning practices and times. They are very dangerous lids. Do not use these lids.
I have also discovered some of the rings from these mainstay canning jars do not fit right on the jars. They pop off under pressure. That would tell me that the sizing is off. It happens water bath canning or pressure canning. I have had it happen through both processes.
Although the original post is a couple of months old, I felt I had to respond.
My Mom and I can (water bath/pressure) at least 300 jars annually, and we always buy Ball brand lids. Well, years ago there were other quality brands like Kerr, but Ball is the only trusted brand we have access to now.
Just last week, the local big-box store was out of Ball lids, so I thought I'd try the only other brand the store carries, their store brand, Mainstays. Upon removing the jars from the pressure canner, the Mainstays lids were buckled in a crease-like fashion. By some miracle, the jars did seal with a resounding snap. However, I question the integrity of the seal due to the severe crease the lid had upon removal from the canner.
A quick internet search reveals similar results with the Mainstays lids, although some users reported the jar losing its seal in storage.
I will be returning all of the Mainstays lids I purchased and will never purchase a Mainstays jar, band or lid again. Why take the chance when Ball manufactures a proven, quality product right here in the U.S.A. The Mainstays canning supplies are made in China.
Mainstays lids are clearly a questionable product and in my opinion, inferior. I trust that Granny knows her way around the kitchen, and the failure of the lid is no fault of her own.
I also have had the same issue with the cheaper lids from Wal-Mart. They look all bubbled up as though they were going to blow off the jar. Buckled and under pressure. When cooled they pulled in some but remained creased. Not smooth. Several jars did not seal at all.