Muffy1938 – Another thing I do before vacuum-sealing any type of dried food in glass canning jars is, a few days before I plan to do the vacuum-sealing, I take any new lids/flats I plan to use and place them in simmering (but not boiling) water for an hour or so. I then remove them from the water and let them air dry very, very well before I use them to vacuum-seal the jars. This may not be a necessary step but I think it may help soften the gasket material on the lids/flats a little bit, making it slightly more flexible and, hopefully, thus better able to conform to the rim of the jar I’m trying to seal. Again, this might not be necessary, especially with the new lids/flats being manufactured these days, but I still do it just in case. If I’m re-using an old canning lid/flat for the vacuum-sealing, I don’t bother with this step. (Note: I do not re-use canning lids/flats for water bath or pressure canning though).
