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….
- 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.
- Tap on the lid. Does it sound tinny or hollow? Tinny means sealed, hollow means poor or no seal.
- 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?
What am I doing that some of my jars don’t seal?
The answer is here: https://foodinjars.com/blog/my-jars-didnt-seal-what-happened/
After canning tomato juice some of my lids ping when I touch them on the middle. I use ball lids. Does this mean they’re not sealed ? When I touch it it stays down.
That happens sometimes. As long as they remain sealed and concave, consider them sealed.
Can I take the rings off while the jar is hot to check the lids?
It is better to wait until the jars are cool before you remove the rings. If you do it too soon, you can risk dislodging the seal.
Hi Marisa,
This has never happened before, but I just now heard a pop from the pantry and found one previously sealed jar of homemade orange marmalade had somehow unsealed. (The one piece lid was raised and no longer indented). I’m pretty sure that this just happened now because I heard the sound (which sounded similar to when the lids pop down right after processing). The marmalade does not look or smell strange. I’m just wondering if the marmalade would still be safe if the jar spontaneously unsealed on its own like this. Any thoughts? (The other jar from the same batch is still sealed. I made this batch exactly one week ago).
Thanks a lot!
Given that you just made that batch a week ago, and there are no visible signs of mold or other spoilage, I would feel fine popping that jar into the fridge and using it up. Botulism isn’t possible with something as acidic as orange marmalade, so there’s no chance of it being dangerously spoiled. My guess is that there was some small particle on the rim that caused the seal to go bad.
I made banana butter (there is lemon juice in the recipe). I check the lids after canning by lightly trying to pull the lid off. All jars were sealed. When I went to open one with a little plastic lid lifter it opened fairly easy and didn’take a sound or if it did it was very quiet. How do I know if it was safe? I threw it out just in case.
There’s really no way to know other than to trust your recipe and processing. You don’t always get that release of suction sound when you take the lid off a jar, though.
I have been canning for a few months……. Did 4 quarts of a heavy bisque-there was some siponining maybe about 1/2”- was able to pick up all 4 cans by the lids and it seems tight- but when i tap with a spoon i don’t hear a ping…..
I am wondering if the ping is due to the clean connection between the lit and glass and if you have any fat from siphoning on the rim- you may get a seal….. but it will fail over time…..
I’m thinking these jars i will just refridgeration and try again…..
Thoughts..
I don’t believe that there are any safe for canning bisque recipes out there. I would discard immediately.
Hi last season I canned (water bath) lots of tomatoes. I found one with some sort of mold or something growing in it so I dumped it. The rest look good and tops are all concave in center. It doesn’t seem to take much effort though to pop the lids off. Should I be concerned about there safety?
As long as they still appear sealed, they should be fine. When you open a jar, listen carefully. Does it sound like a seal is being released? It’s okay if it’s not a huge challenge to remove the lids, but if they pop right off without any sort of suction release, it might be time to dump those tomatoes.
16 hours after my salsa processed I touched a lid with a slight bubble. It popped down and stayed. Now I can’t tell which bottle it was! What do I do??
It’s okay. That happens sometimes.
I been canning like crazy then realized the stuff that’s was canned they all sealed but I can pop the lids off with my finger tips. I’m lost so much work for nothing 😩
That is very frustrating. I am so sorry!
When I tap my applesauce jars with a spoon they sound hollow, but I can lift the jars from nothing but the rim of the lid, is this because there was air in my apples causing the sauce to “float to the top? I left headspace in the jars before sealing, there appears to be no headspace now. Thanks for any feedback
Applesauce often expands in the jars during the canning process. As long as the seals seem firmly adhered and the lids are concave, you should be good.
When I first jarred my tomatoes, the lid didn’t move it was sealed. I checked on it a week later, and I was able to move the top and I don’t know what I did wrong.
Is it actively clicking up and down? Or do you only sense a very small amount of movement? If the seals did fail, it’s hard for me to determine why since I’m not there.
Hi. I canned stewed tomatoes 3 days ago using a pressure cooker method. The jars appear to have sealed fine – press test checks out and they pick up easily using the lid (without the ring). But the tomatoes slosh around inside the bottle, and there’s a gap of about an inch between the top of the liquid and the top of the bottle. From the outside, it appears as if there’s no suction inside. I’m not sure whether this is to be expected, or if it indicates that I didn’t do the seal properly. Again, the seal appears to be fine from all of the checks that seem appropriate. Any insight?
The product should always be able to move around the jar. That’s totally normal.
What if they didn’t suck down, but when I pushed to test them they pushed down and stayed down?
Sometimes that little touch is all they need. As long as they stay sealed, they are fine.
Can I refrigerate jars of dill
Pickles that haven’t sealed properly and still eat tgen
Yes.
I canned green beans last night and one canner got low on water so i boiled some in an extra pan and added to it..let finish canning time..turned off and left in canner maybe half hour before taking out and setting on towel lined counter to finish sealing and to cool..
This morning I checked them ..one looks like the button is down however the lid looks like it “warped “..
Can i reprocess by adding new lids ? And for how long do i process them
Were they pickled? Or were you pressure canning them? If you need to reprocess them, you have to start the entire process over again.
Hi Marisa,
I have one jar of canned chicken for which the seal did not hold after storing on my shelf. I know I must dispose of the lid and contents, but do I need to dispose of the jar as well, or can it safely be washed and boiled and used again? (jars have gotten so expensive!🥴)
Thank you in advance… your site is great!
Diane
You don’t need to throw the jar away. Just wash and sanitize before using.
I processed and refrigerated 12 jars OF Blackberry jam a few months ago. Now it seems a few of them slide to the bottom when turned upside down. Are they safe to eat? They are still in the fridge. Thanks
That’s pretty normal. The jam set firmly and so it moves around as a solid block when you turn the jar.
I used some Kanaware seals last week, but didn’t notice until I was ready to put them on the jars that they were flat – no button. How do I know if they sealed properly?
They should still feel firm and solid to the touch, no wiggle or movement after processing.
Hello, I made cowboy candy and it says to cover peppers with the liquid. After processing in a water bath, some jars peppers aren’t covered with liquid, but the lids popped. Are they still shelf stable or should I refrigerate them?
As long as the seals are good, you are all set. The peppers that are exposed might soften and fade more quickly than the rest of the jar, but there’s no safety concern.
If they didn’t seal is my batch no good
Do I have to start over
It depends on what the product is that you made. You can reprocess things like jams and jellies, but I don’t recommend it for pickles, as they will become oversoftened.
I canned some pasta sauce after 12hrs I checked and they were all sealed but on 2 ofy jars there eas some leakage. I unscrewed the bands and jeld jars by the lid amd checked to see if they had a good seal. They did.y wusetiin is with leakage after letting them seal are they still good for self or do I need to use put in frig and use them within 7 days. Thank you for your help!!🙂
Jars sometimes siphon a little bit of product during the canning and cooling process. As long as the seals are good, they jars are fine.
I made pepper relish and today there is a lot of bubbles in the jar does this mean its working and no good
The bubbles are only an issue if they are moving as if carbonated.
I am wondering about:
I made peach jam this morning , (without pectin) When I place the mixture in the jars the pinged about 15 minutes later. Are they safe to store on the shelf or do the go in the fridge?
You put hot jam into jars and let them cool on the counter without doing any kind of boiling water bath process? Those jars need to go in the fridge.
canned some plum sauce and a few jars came out sticky around the mouth, but totally sealed…good to go?
Entirely good to go. Sometimes jars leak a little during the canning process, but as long as the seal is good, it is inconsequential.
After the cans have cooled, I have one lead where the ball is not indented. After I pressed it down, it stayed indented and does not pop back up. Does this mean that my jar is sealed?
Keep an eye on it and check the seal after a week or so. If the seal remains down, you should be alright.
I canned 24 pints of tomatos. They all sealed but sound like a gun went off when they popped. All lids bulked. I checked the seals and could not prove off the the lids with my hand. Are the safe?
Lids can make a range of noises when sealing, and even no noise at all. As long as the lids are somewhat concave and don’t wiggle when pressed, they should be fine.
I canned 7 jars of salsa, none of these popped, but all of them are firm when I press on the center of lid. I don’t understand why none of them popped. I usually hear popping sounds very quickly after putting on the lids. Just wondering if they are sealed? Thank you for your help
Some of the newer lids don’t make the same popping sound that they once did (Ball changed the thickness of their lids slightly, which typically accounts for the change in sound). As long as the lids are solid, seem well sealed to the jars and don’t wiggle at all when pushed, they are fine.
Hello.
I water bath my cucumbers for the first time today. If the jars sealed and passed the lifting test then they are 100% safe for the pantry? Nervous beginner
They should be just fine!
there is a small dent in the lid of my freshly made tomato sauce. is it ok or should I reseal? its on tight
As long as the metal isn’t broken, a small dent isn’t an issue. No need to reseal.
I use the lids the second time if they are not damaged, we were unable to get lids during covid and even yet so I decided then to reuse,I remove the bands wipe the bottle and lid clean and Never had a problem with anything,if they don,t seal I freeze it
I understand your reasoning, but it’s still not a great idea.
I made jalapeño jelly and it is thick and I noticed after a couple of days the lid did not seal. Is it safe too eat or should it away.
Since it’s only been a couple days, you should be okay to just move it to the fridge.
How do you check for a seal if using lug lids with a button? Are you still listening for a higher pitched noise when tapping on the lid with a spoon? What if the lid is firmly concave but the sound is slightly duller? I ask because I just processed 10 jars of blood orange preserves and three of the jars tops are firmly concave but the sound is a bit duller than the others. I use between 1/8-1/4” head space. Ones with the duller sound are filled a bit more?
Thank you for your help.
The tapping method is not one that has ever really clicked with me. I just press hard and feel for any movement. A sealed lid should have little to no give.
Hello
I appreciate your content! I have a question about sealed lids. I did all the tests, listened for the noise, picked the jars up by the lid, did a visual test, etc. After doing all of these, I have a habit of trying to remove the lids with my finger nails. If it doesn’t budge at all, I feel really good about the seal. Well tonight, I did this same test on my pork chunks and a jar of navy beans. With a lil force from my finger nails, the lids came off. Still noticed the suction noise as the lids were removed and neither smelled or looked off. Do you think they are safe to consume?
Thank you in advance for your help 😊
Without experiencing the seals first-hand, I really can’t advise you. I do find that things processed in a pressure canner typically have a VERY strong seal. I might question a pressure canner product in which the seal came off with a just a small tug with your fingertips.
Just checked sealed jars down stairs I tap each top of them. There’s one that makes tinny sound . I don’t keep the rings on them .
I turned it up side down and nothing happened just the sound is off?
This is chutney
The sound is not an accurate test of the quality of the seal. Does the lid wiggle at all when pushed? Does it stay sealed when you lift the jar holding on to the edges of the lid? If the answer is yes, it is fine.
My cap is slightly up looking on one jar of sweet pickle relish. It does not go down when touched but appears like a slight button. Should I trust it’s good and because it’s sweet with vinegar, how could I tell if it is spoiled. It’s been about 3 weeks since I made them.
Nothing dangerous can happen in a preserve like that. I’d move it to the fridge and use it first.
I removed my applesauce from the canner and didn’t hear any popping and after they sat on table I didn’t hear any popping
After an hour or two I noticed the center of the lid was raised up. I touched the center and it pushed down and didn’t pop back up
The lids are tight and not moving up or down when I push on it
Am I ok
Do the seals hold if you remove the lids? If so, you should be okay.
My lid pinged when I was processing the tomatoes in the water bath. The lid was on firmly & didn’t push down when the jar was cool. Is it properly sealed & safe from contamination?
If you properly processed the jars, they should be sealed and reliable.
If the jars have not sealed what can you do.
Reprocess. Or refrigerate and use promptly.
I canned tomato juice using lids that were not name brand like in the past. There were no popping sounds but when I checked there was no movement in the lid. I took ring off and pulled up really hard with my fingernails….it didn’t come off easy but did come off. Now I am worried if there is enough of a seal on the pint jars….I had to really pull hard to get lid off, but is it normal for it to come off without a hand opener?
The lids really shouldn’t come off like that. How long did you let them rest before checking the seals?
Hi! I made a large batch of sweet relish and had two lids with the centers popped up, not concave. After removing the rings and lifting the jars by the lids, one of the lids came off so definitely not a good seal on that one. It is in the refrigerator now. The other jar, however, passed the test when I lifted it by the lid, several times. It’s been well over 12 hours since the water bath but under 24 hours. Can I trust the jar that passed the lift test, even though the center is popped up and not concave? Thank you.
If the lid isn’t concave, it doesn’t have a reliable seal.
I have five pints of corn that were seal when I put them in storage lost their seal three weeks later what happened
Faulty lids, perhaps?