Anatomy of a Canning Jar
Updated: Oct 17
Emmaline and marie both love and adore vintage canning jars, but for Modern canning, we recommend that you don’t go vintage. Old canning jars with colored glass or spring-type lids are beautiful collector pieces. They may have irregular sizes, may crack, and have greater chances of failed sealing. we recommend that you use them for spices and dry goods.
There are 4 parts to modern canning jars:
Canning jars are molded from a thick glass that is made to withstand heat and pressure year after year. Jars come in a variety of sizes that we discuss in the following section.
Metal canning flat/lids are sold as single use. They are available in regular and wide-mouthed varieties. When purchasing new jars, the lids and bands are generally included, but you can also purchase new lids separately.
The Lid Sealing Compound
On the underside of the canning lid is a ring of sealing compound. This compound seals the lid onto the jar using what is known as a hermetic seal.
The Ring or Band
Canning jar rings or bands may be reused. They secure the lids to the jars during processing. After processing you should remove the bands and wash the jars before storing them in your pantry.
Resealable Canning Lids and Gaskets
Reusable Canning Lids
Lid and sealing compound alternative – reusable canning lids
Marie grew up knowing that you don’t reuse canning lids. She always bought canning lids in bulk whenever she could find them. They were considered a yearly unavoidable expense. That is until she found reusable canning lids.
At first, Marie struggled with the idea of reusable canning lids, unsure how they would perform. Even her mother and her good friend, Joy, who have canned for years, had never used them. In fact, she found out both of them had the reusable canning lids in their cupboard for multiple seasons but had never used them.
Emmaline had never even heard of reusable canning lids and she loves to can. We decided to include them here to help others to know and understand there are some other options available. We also want you to have the most success using these lids as there are a few slight differences.
Reusable Canning Lids
Differences Between Regular Canning Lids and Reusable Canning Lids
There are some differences between reusable and regular canning lids. Those differences can make a difference in how well your processed jars seal and we believe are responsible for most people’s reluctance to try them. Here is a list of the things to do differently if using reusable lids for a successful seal.
Heat up the gasket in simmering water to increase its pliability and ability to seal.
Leave a 1 1/2″ headspace. This allows more room for the vacuum to form since the lid depresses into the jar more than the regular metal disposable canning lids.
Do not overtighten the rings. It should be truly fingertip tight so that the air can escape during canning. Place a left-hand (nondominant) finger on the lid to hold the jar in place. Use your right-hand (dominant) fingertips to tighten the ring. When the jar moves when you tighten it, you know that is tight enough.
After removing your jars from the canner, allow them to cool for 3 minutes, and then tighten the ring.
Let your canned goods sit a full 24 hours before removing rings and storing your preserved foods.
The difference between using regular versus reusable lids isn’t really that much of a difference in workflow. It just requires a little getting used to. We feel like using these lids is so worth it. We not only save on our annual canning expenses but we keep more out of our landfills.