All the jar rings were loose when I removed my canning jars from the canner. I tightened them all. When I went to store the jars, I noticed that none of them had sealed. What happened?
Retightening jar rings after processing causes a condition called "cut throat." The ring cuts right through the sealing compound leaving the enamel against the glass jar rim. Loss of seal usually occurs. Never retighten jar rings. Don't disturb canning jars for 12 to 24 hours after processing while seal is forming.
Barbara Willenberg, Nutritional Sciences, University of Missouri-Columbia
Last update: Tuesday, May 05, 2009