In this episode we discuss the most frequently asked general canning questions we get on our blogs, social media, and in person and we share the up to date, tested answers to questions and pitfalls.
Canned food can be safely recanned if the unsealed jar is re-processed in a jar with a new lid within 24 hours of discovery of an unsealed lid. Processing time remains the same.
If a jar of canned food is frozen during storage, there’s no reason to worry. The food is still safe to eat.
You must process jars of food as determined by a tested canning recipe. Many old books give directions for open kettle method which is no longer recommended. Use up to date canning recipes.
Headspace is important for driving oxygen out of jars, preventing spoilage, and creating a vacuum tight seal. Maintain proper headspace.
Properly canned food will keep (be safe) indefinitely, but most foods are highest quality when eaten within a year.
Two layers of jars can be processed at the same time in a water bath, steam canner, or pressure canner IF there is a rack used to separate the layers.
It is critical that you exhaust a pressure canner before bringing it up to pressure.
Liquid lost during the processing of jars should not be replaced and is often typical, depending on the recipe. Excessive loss (2-3 inches of liquid) is called siphoning and can compromise the seal integrity.
Do NOT reuse lids in a 2-piece metal lid system.
Lids sometimes discolor because of the foods canned (tomatoes are a common culprit) and discoloration does not signal spoilage.
Broken jars in the canner can be caused by using commercial jars rather than canning jars, using cracked jars, placing jars directly on the bottom of the canner rather than on a rack, putting hot food into cold jars, or putting cold food into the hot canner.
If you find mold inside a jar of food, the food should be discarded.
Add a splash (a few tablespoons) of white vinegar to the processing water in all canning processes to avoid the hard water film from forming on jars.