I seem to remember a real shortage of lids many years ago and we were going to out of the way places to find them. That taught us to keep at least a one year supply ahead. As far as shelf life of new lids go we have no way of knowing how long those lids sat in a warehouse before being purchased. ..
>>>I seem to remember a real shortage of lids many years ago and we were going to out of the way places to find them.<<<
About 35 years ago, I remember them being in short supply - one company made high temp plastic ones with silicone seals - you could reuse them over and over. One of the jar companies (there was more than one then - now they are all owned by Jarden) bought them out and then discontinued them.
I have about a dozen 6 year old spaghetti sauce jars and one-piece lids with silicone seals that pop down when sealed - have used them every year (sometimes twice in same year) and they perform flawlessly - over and over. The technology is there, but the financing to get approval, the ability to survive the legal wrangling results in the will to produce such a product being unachievable. Reminds me that ‘Government isn’t the solution - Government is the problem!’