How to Check That Your Seal is Good

concave lids
I got a question tonight from a reader of this blog about seal quality and as I was writing her back, I realized that there may be more of you out there who could benefit from a brief seal-testing tutorial.

When it comes to canning, sometimes you miss the pinging sound that gives you auditory confirmation that your jars have sealed. Just because you didn’t hear it doesn’t mean that the jars didn’t seal. Here are some ways to test….

  1. Press down on the center of the lid. Does it move up and down or does it feel solid and concave? Solid and concave means a good seal, movement means no seal.
  2. Tap on the lid. Does it sound tinny or hollow? Tinny means sealed, hollow means poor or no seal.
  3. Unscrew the band you used to hold the lid in place during processing. Now attempt to pick your jar up holding onto nothing but the lid. If you have a good seal, you should be able to do this easily. You’ll know pretty much right away when you remove the band whether your seal is good.

How else do you guys check your seals? And, while I’m answering questions, who else has got one?

Related Posts:


100 Responses to How to Check That Your Seal is Good

  1. 51
    Tiffany says:

    Can I seal the jars by the heat of the content alone because I’ve done that and they sealed, made a popping noise and everything and they’re completely sealed without the water bath, is that ok? I sanitized my jars and lids first.


  1. Preserve a Peck of Apples – Part 2 « The Foodie Scientist - November 25, 2009

    […] in the bottom of the pot to keep the jars from bumping and cracking) Once the jars have cooled, check the seal and reprocess any unsealed jars or use refrigerate and use those jars immediately. Store jars […]

  2. Canning Salsa | Eva Was Here - September 19, 2013

    […] while they were boiling. Not all of my cans sealed properly (I found some simple tests for seals here), so I reprocessed them the next day for another 15 […]

  3. Meyer Lemon Curd, simple or spiced: Edible holiday gift gold | One Hungry Mama - December 6, 2013

    […] food safety of your gift! If you’re feeling unsure or worried, check out this awesome post on how to check if your seal is good by the small batch canning queen, Marisa […]

Leave a Reply