Follow These Steps to Seal Jars of Preserves
Question: I recently made several jars of apricot preserves and although I made them all the same way, about half did not seal. Can you suggest any reason why and tell me what the storage or shelf life should be for the unsealed jars?
Answer: Since your letter did not indicate for certain, we’re assuming you used the combination lid and screw band closures with standardized jars. Both Ball Corp. and Kerr Glass Manufacturing Corp. recommend the boiling water bath method for canning preserves. The following steps are compiled from both companies’ instructions:
--Examine the jars to see there are no nicks, cracks or sharp edges. Check the screw bands and discard any with dents or rusted areas.
--Wash the jars and bands well in hot, soapy water. Rinse and place in simmering water.
--Be certain to use lids with new seals. Place the lids in a pan, pour boiling water over and let stand until ready to use.
--Remove the jars from hot water with tongs just before filling. Pack hot preserves into hot jars to within a quarter-inch of jar top. Remove air bubbles from the jar with non-metallic spatula. Wipe residue from top edge and threads of the jar with a damp cloth.
--Place the prepared lid on the jar with the seal next to the glass and screw the band down firmly by hand.
--Place the jars in a boiling water bath canner rack and carefully lower into a canner filled with boiling water. Add boiling water, if necessary, to bring water one or two inches over the tops of the jars. Cover the canner and bring water to rolling boil. Begin counting processing time at the point that rolling boil begins. Allow water to boil gently, but steadily, for time specified in recipe, generally 15 minutes for pint containers. Remove the jars from the canner and allow to cool.
--As the jars cool, slight pinging noises may be heard, indicating that a vacuum has formed and the jar is sealed. The center of the lid is pulled down by this vacuum, creating a slightly concave surface. If uncertain whether the jar is sealed, push down on the lid center. If it does not push down, the jar is sealed. If the lid is not already concave, but holds when pushed down, the seal is questionable. Remove the screw band and carefully lift the jar by the edges of the lid just a fraction of an inch over a padded surface. If the lid comes off, the preserves should be reprocessed or refrigerated and consumed within two to three weeks.
Before storing, remove the metal bands from the sealed jars, be certain the jars are clean and label with contents and date. If stored in a cool, dry, dark place, preserves should remain optimum for a year.
Carefully following those steps should result in sealed jars. According to the manufacturers, the most common problems result from damaged jars or screw bands, not cleaning the jar edge well, not screwing the band down firmly and lack of heat during processing.