I think that this is the part that most people panic about when it comes to safe home canning. Did my jars seal? Are they safe for my family to eat? How can I be sure?
Once you have the basic pressure canning or water bath canning part down, you shouldn’t have much to worry about. But do you know how to test a seal on a jar properly? Here are some things to look for…
The most common method for testing jars is the Finger Test Method. Simply press on the middle of the jar lid with your finger. If the lid “pops” up and down with your finger when you press it, it’s not sealed and needs to be reprocessed.
The next method you can try is the Spoon Test Method. Tap the lid with the bottom of a spoon. If it makes a dull sound, the lid is not sealed. If it makes a pinging noise, it is correctly sealed.
Of course, you can also look at the lid at eye level. If the lid looks flat or bulging, it’s not sealed. If the lid is nice and concave, it’s properly sealed!
Do not remove a jar rim before the jar has cooled, but DO remove the rim before storing the jar. Re-tightening a rim after the jar is sealed can cause the seal to break.