Unused Lids
According to Jarden Home Brands, the manufacturer of Ball home canning jars, lids and bands, unused lids should be stored in a cool, dry place. Helen Aardsma of Mulberry Lane Farm reports that lids have a shelf life of five to 10 years if stored properly.
Sealed Lids
Jarden states that if correct canning procedures are followed, preserved foods with sealed lids should last indefinitely. A lid corroded on the top is OK as long as the vacuum seal between the lid and jar is retained. Freezing can cause the seal to break.
Reuse
According to the manufacturer, lids are for "one-time use only." Once a lid has been used, it may not form the all-important vacuum seal needed to preserve the canned food a second time around. Aardsma shares that about half the jars did not seal when she tried reusing lids once.