We have had some quarts of tomatoes leak and ferment. They sealed when we processed them. We took the bands off figuring they would stay sealed. Now I'm thinking we should leave bands on. ?

We always leave ours on.

If you don't get a vacuum, you are probably screwed either way.

We always take our bands off after they have cooled down.leaving the bands on has nothing to do with your jars sealing.its when the jars start to cool down that you get a vacuum that pulls the seal down and you hear the popping noise that they make.once that happens they should stay sealed with the bands off.

We leave them on to protect seal. Jars get knocked around plenty moving things in pantry.

We take them off and use on the next batch.

Take them off or they will rust to the lids.

The official recommendation is to take them off.

Some of mine are both ways. I prefer to take them off and then wash the jar before storing, because if you don't, anything that seeped out of the jar during processing before they sealed will sit under that ring and mold. That doesn't really hurt anything (since it's on the outside of the jar) but just looks gross when you go to open it.

The rings aren't going to help keep a seal.
Even with the rings on or off , if the seal fails , the ring had nothing to do with it.
I never leave rings on for at least two reasons, it's really not needed, and the rings can be used on another batch.
I remember when I first started canning, would leave the rings on, and needed to buy more rings as the rings were all used up.
Now as soon as cooled , for 24 hours, take rings off , make sure they're clean and dry. Store for the next batch.
How many times have you found rusty rings on your canned goods?
Take the rings off , and you always have enough rings.

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If they did not stay sealed its possible you didn't get the top of the jar wiped off good or there is a small defect in the jar. poor quality flats is another possibility

the bands can keep the mess down if something happens to compromise the seal but don't keep it sealed

they might prevent bumping the lid and breaking the seal but sitting on a pantry shelf that shouldn't be much of an issue

Only time I put rings back on a jar , is when it's a gift.
I never leave rings on.
When gifting jams, jellies or pickled anything that needs a lid for the refrigerator, is the only time lids are on.
Have gone camping with plenty of canned goods, and never had a problem with lids coming off just by accidental bumping.
A good seal isn't going to break by just bumping it.
A one time use jar of anything doesn't have a ring on it.

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Take em off. The band doesn't make a bad seal good. Leaving them on year after year they will eventually rust. Take them off, wash dry and store them. They'll last a lifetime

I've always left mine on the jar. No real reason other than habit. Seems like there's plenty of reasons to take them off.

I always have plenty of the bands and figured it made it less likely to have the seal broken by accident and just left them on. Sounds like I would be better just taking them off.

I like leaving the bands on. I think that the bands would slightly protect the lid if the jars did make contact with each other. I have plenty of bands too. If I didn't have enough bands, I wouldn't worry about it.

Keith

?????????? You wouldn't worry about having enough bands , when in the middle of a batch?
I used to buy used jars until I had more than I needed.
There's always a need for bands , lids , and that's why I don't leave bands/rings on.

I take them off. If for whatever reason the seal fails, you will know it. The lid will be loose and floating. If sucked down, it's still good. I keep about 3 doz regular bands and about 1 to 2 doz wide mouth....kept in a small bucket. Been using same bands for years. Have 10X more jars than bands. Few years back we were gifted an elderly lady's jars.....no lids or bands.

Take them off. You’re gonna be fighting them off later if you don’t.