Putting Food By - Janet Greene [39]
CHECKLIST FOR POOR SEALS
One poor seal out of a full canner batch is a disappointment, but not a worry. Nor is the food in only one container worth reprocessing, which means getting cranked up to start over from scratch with a fresh jar or can and a fresh closure, and repeating, with utmost care this time, every step in the whole canning procedure. Best to eat it right away.
But two poor seals?—not so good. And more than two seal failures in one canner batch will tell you that you’re making at least one mistake in your canning technique. For your family’s sake, see if it’s one of these:
Short cuts in sanitation or preparing food “because it will sterilize anyway.” Manufacturers’ directions not followed in preparing closures.
Imperfect or makeshift containers/closures. Sealing edges of jars or permanent closures (glass tops) have nicks/cracks/warps. Jars are “one-trip” commercial containers, plus commercial lids from peanut butter, mayonnaise, pickles, etc., or baby-food jars. Rusty or bent bails on old jars (with extra padding to take up slack?). Re-used sealers (rubber rings or metal lids with sealing compound). Dented/bent cans or can lids.
Haphazard filling, exhausting, capping of containers. Packing too tightly or too loosely. Too much or too little headroom. Trapped air not removed. Cans not properly exhausted before capping. Sealing rims not wiped clean after filling. Screwbands of modern two-piece lids not “firmly tight” to hold lids snugly on and in place during processing; bailed jar lids not allowed necessary venting. Cans not properly exhausted before sealing. Can-sealer not tested/adjusted.
Processing kettle mismanaged. Water in B–W Bath not 2 inches over tops of containers; Pressure Canner not vented long enough to remove air (or, if used unlocked as a substitute B–W Bath kettle, not vented long or strongly enough before starting to time processing period). True boil not reached and maintained in B–W Bath; called-for pressure not reached (gauge unchecked?) or maintained; full processing time not used. Maker’s instructions for mechanical operation not followed. Pressure allowed to fluctuate, so contents lost from jars and trapped between jar rim and lid—thus preventing good seal.
Processing method inadequate. Maverick or makeshift method used. Adjustments for altitude above sea-level zone (up to 1000 ft/305 m) not made. Incorrect venting or return-to-Zero of Pressure Canner (made to cool quickly? lid removed before Zero?).
Containers mishandled after processing. Modern two-piece screwband lids were fiddled with (notable offense being brisk tightening of the screwband, which usually loosens slightly during processing); seals not completed as needed for bailed jars.
Cans not cooled quickly enough; but jars left in B–W Bath kettle after processing time is done OR were wrapped to slow down natural cooling.
Jars inverted to cool: wrong and unnecessary.
Jars/cans roughly stacked for storage or in other ways knocked around, thus hurting seals.
Cleaning and Labeling
Twelve hours after they’re processed, remove the screwbands and wipe the jars carefully with a clean, damp cloth, paying special attention to the area around the seals.
Never force a reluctant screwband. Hold a hot cloth around it to make it loosen by expanding; if this doesn’t work, mark the jar for special watching while it is stored, and turn to the next jar.
The modern metal closure doesn’t need a screwband to ensure the seal, of course—but the band does protect the seal in case you plan to transport the jars or stack them. Don’t replace the screwbands if you take them off, because