How to tell if your canning jar lids are new or used.
It's all in the Seal
I was asked how to tell if a lid has been used. You can tell by the sealing compound. If it is used it will show an indentation from the rim of the jar.
If not used... it will be smooth. I took a picture of two lids. One is used - One is new. Can you tell the difference? (answer below the picture... don't cheat! Decide first then scroll down and look.)
It might be hard to tell but the lid on top with the gold finish is the new the lid. The lid underneath with the white finish is the used lid. Another way to put it, the lid on the right is the new the lid on the left is the used.
There are no canning police.
This of course leads to the next question... does it matter. My answer is Yes, it does matter.
This indent in the sealing compound makes a failed seal more likely if you try to reuse the lid. I don't like to waste my time and food for a higher chance of failure. So my recommendation is... don't reuse lids. (It also happens to be the recommendation of USDA and all traditional lid manufacturers that I know of.)
I just know that I will get tons of replies from folks who have reused lids. I don't recommend it.. you have to make your own decision. Remember there are no canning police. :)
Some other ideas.
Question from Sharon's inbox....
Help, the lids on new jars are marked.
Alan asks: Good day, I have 2 quick questions. I purchased some 1qrt knorr jars and put them away. After about a month or two I pulled them out to use them. As i took the rings off to put them in the hot water to get them sterilized they popped on me.
I checked the lids and they seemed OK but with the edge of the jar marked down on the red gasket part. Are those lids still good? and second. how can I avoid these jars from creating impression while they are in storage?
Yes, unfortunately many manufacturers of jars place lids on the jar in the box. I assume this is to save space and packaging. I wish they would just place a box of lids with the jars instead. What happens is the jar leaves an indentation. I'm sure the boxes probably get warm while in storage and this will just exacerbate the problem as the sealing compound gets soft when heated. This is precisely why we simmer them before use, to warm them up.
Your best bet is to remove the lids from the jars when you get them. As far as them still being useable it will depend on the how deeply the jar seals are marked. That is something I can't really tell you. You'll just have to decide if it is worth risking a failed seal. They may be fine... they may not.
Wish it were an easy answer.
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