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How to Know If Canning Lids Are Sealed

Many people worry about the safety of home canning. If home canning guidelines are followed correctly, eating home canned food is safe. Not to mention that you will never get the taste of home canned goods from food bought in a store. Plus, you can control the ingredients that are added. No more high sodium canned food or msg and other unhealthy additives!

After the canning process, it is important to be sure that the canning lids are sealed correctly. Incorrectly sealed lids can result in food poisoning. See common reasons why canning lids didn't seal.

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Old fashioned canning jars photo: Patrick Q @flickr

Old fashioned canning jars photo: Patrick Q @flickr

How to Know If Canning Lids Are Sealed

How can you tell if your canning jar is sealed properly? First, let the canning jars cool overnight before testing the seals. Don't try to check them when they are still hot.

To inspect them visually, your canning lids should sink in a bit. Press on the center of the lid with your finger. If it sealed correctly, it will do nothing. If your canning lids didn't seal, they will give a little and may make a small sound. Also, try tapping the canning lids with a metal spoon. They should make a slight ringing sound.

Often you will hear the cans make a popping noise when they start to cool. This happens when the air leaves the jar and the vacuum seal forms. Be happy when you hear all of those little pops! But a jar doesn't have to make the popping sound in order to be sealed correctly.

The food doesn't have to go to waste if it didn't seal properly. Just put the jar in the refrigerator and use the canned food in two or three days. Or freeze the food for longer storage.

Another option is to reseal the canning jar. This must be done within 24 hours at the most, though. Check the jar itself to see if it is defective in any way. That may be the reason the canning lid didn't seal. If the jar is okay, repeat the original canning process. Don't forget to use new canning lids. Some people say that it's okay to reuse canning lids. I would rather be safe than sorry. Look for sales, especially at the end of the season. If you're vigilant, you can find canning lids on sale pretty cheap.

If you can't stand the thought of throwing away canning lids after just one use, there are other uses for them. Be creative, or look up ways to reuse canning lids on the internet.

You can reuse the canning rings if they haven't become rusty or dented. But never try to reuse canning lids. You have to take some precautions to keep canning jar rings (bands) for a long time. Remove the jar rings after the jars have cooled completely, probably overnight. They will rust easily if you leave them on the canning jars. Then wash the rings to remove any possible food residue. Dry them really well. Keep them stored somewhere away from humidity so that they don't rust.

How to Know If Canning Lids Are Sealed Comments

Courtney on August 02, 2012:

I canned some pickled okra and two of my cans sealed and the other two didn't so I put them in the fridge. When I checked them later, the lids didn't pop! Are they really sealed now??

RACHEL on September 01, 2011:

Hi I canned with my grandma for the first time yesterday so I'm just learning. We did whole tomatos and she was told me that if they aren't floting in the jar with at least an inch of liquid that they probably didn't seal. Well this morning I have 5 jars that aren't floting does this mean I need to use them now?

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Char on August 31, 2011:

I am new at canning. After canning pickled beets, I was waiting for the can to make the popping sound and began wondering if they sealed correctly. After a couple of hours I checked by pressing slightly on my lids. All but two of them didn't budge and seemed fine. Two of them however, popped and sunk in from my finger as though they were just on the verge of being sealed. Did they seal properly or does this mean that I have to redo them because they didn't seal properly? I'm confused.

Gustave Kilthau from USA on June 16, 2010:

Angela - Canning foods can be tricky. Your article is most helpful. Gus :-)))

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