What causes lids to buckle?
The build up of pressure inside jars causes lids to buckle. This is a result of putting screw bands so tightly that air can hardly escape from the jars during processing. Screw bands should be tightened firmly by hand. Do not use a jar wrench to tighten screw bands.
Buckling causes tiny pinholes in the flat. For this
reason, the food cannot be stored on the shelf. Within
24 hours of processing, foods can either be refrigerated
and used within one to two days, or reprocessed.
Barbara Willenberg, Nutritional
Sciences, University of Missouri-Columbia
Last update: Tuesday, May 05, 2009