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high seal failure rate

Posted by lana_lang CAlifornia (My Page) on
Sat, Oct 20, 12 at 20:05

Hi all,

I've been canning a batch of tomatoes ever weekend for the last 6 weeks, and I'm getting really annoyed with the number of cans that don't seal. The average is probably 1 out of 5 that don't seal. I always leave about 1/2 inch headspace, use a plastic spoon to get out air bubbles, use new lids, heat the lids in almost boiling hot water, and wipe the rims clean.

What am I doing wrong? :(


Follow-Up Postings:

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RE: high seal failure rate

Are you pressure canning or BWB canning them? Which tomato instructions are you using - whole, crushed, etc? And are you hot packing or raw packing? All those factors can affect seals.

Is the water in the canner clear or tomato colored when finished? If pressure canning are you doing the 10 min wait between the weight and removing the lid? Are you letting the jars sit in the canner a few mins until they quit boiling? Are you tipping the jars at all when lifting them out? Are you sure you are screwing the bands on tight enough?

Don't heat the lids so hot - they just need to be lightly simmered and many just set them in a pan of hot tap water.

More info please.

Dave


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RE: high seal failure rate

I'm doing BWB, whole, raw packing. I did notice a tiny bit of tomato particles in the water afterward, but not enough to make the water turn red. Yes, I do let them sit a few minutes before removing. I don't tip the jars. How tight is tight enough? I just screw them on until they are "fingertip tight", meaning just until there is resistance.

Thanks, Dave :)


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RE: high seal failure rate

Several months ago...maybe even a year ago...Walmart had a sale on off-brand canning lids. The price was good and a lot of folks stocked up on them only to find that these lids had a high failure rate. What brand lids are you using?


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RE: high seal failure rate

I've been using some old, and new Ball jars w/lids (from those 12 pack cases) and some Kerr lids as well. The new ones I bought from Winco.

Maybe the canning gods just hate me! ;)


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RE: high seal failure rate

Perhaps the old lids are the ones not sealing. I thought you shouldn't re-use old lids.


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RE: high seal failure rate

If by "old" lids you mean ones that you've had for a year or two, that shouldn't make a difference. See if you can identify if the seal failures are exclusive to a particular brand (i.e. Kerr vs. Ball) or fall into all categories. If it's one brand, that tells you it's the lids. If it's across brands, that tells you it's technique.

Are you using old or gifted jars? Did you check rims for nicks or chips?

The more information you can provide the more help we can be.

Carol


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RE: high seal failure rate

Sorry, I actually never use old lids! I meant old jars :) I always use brand new lids. And the jars (I bought new just a few years ago, so they are not that old) don't have any damage that I can see or feel. Maybe I'll stop using the Kerr lids and see if it makes a difference.


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RE: high seal failure rate

Based on the info so far I'd bet on the rings/bands not being screwed on tight enough. "Finger-tight" is different for all so "full finger-tight plus a bit more" might be more accurate.

Some make the mistake of trying to tighten the bands back down when the jars are removed from the canner and that can ruin seals too.

But wife and I use all sorts of brands of lids - from generic to the red gingham cheapies and very seldom have any seal failure. But then we'd never use whole/raw packed method and the 85 min. processing time it requires either.

Dave


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RE: high seal failure rate

I wouldn't think the Kerr lids would be any more susceptible to seal failure than the Ball ones. They're manufactured by the same company.

Carol


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RE: high seal failure rate

Thanks everyone. I think Dave might have a good point about the tightness of the bands. I've noticed that the bands are very loose when I remove the bottles from the canner, so I'm probably not putting them on tight enough.


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RE: high seal failure rate

If you are raw-packing the tomatoes and over-packing the jars that may be part of the problem.

Carol


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RE: high seal failure rate

If you are raw-packing the tomatoes and over-packing the jars that may be part of the problem.

Agree. That particular method of canning tomatoes is the most problematic.

Dave


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RE: high seal failure rate

Hmmm... how do I know I'm over-packing? Maybe I should just switch to hot-pack method. I guess I've always just raw packed because the processing times are the same for each and it saved me a step. But maybe it's more trouble than it's worth :(

So for hot-pack, how much water do I add? I don't want to have watery tomatoes.


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RE: high seal failure rate

Whole/halved packed in water has half the processing time 40-45 min. Link explains how much water.

Crushed with no added liquid (the most popular method) calls for even less time 35-40 mins.

Of course if you switch to PC canning them the times are cut even more.

Have you checked out all the different methods posted at NCHFP?

Dave


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RE: high seal failure rate

shoot, I've been processing my raw tomato pints for 40 minutes for as long as I've been canning! I quarter the tomatoes first (just because they are usually huge and won't fit otherwise), and there's rarely any room for adding water. So, I guess they are essentially "crushed", just not heated first. Yikes.... I guess I'll be switching to the crushed-no-liquid-added method from the website. I have looked at the NCHFP website before, but I guess I was confused about what constituted a raw vs. hot pack. I must have been overpacking the jars, since there wasn't much room to add water. Thanks for clarifying this for me, Dave!


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RE: high seal failure rate

Whole or Halved Tomatoes packed raw without added liquid processing time is 85 mins. for pints or quarts.

If you have been processing them for only 40 mins. then they have been way under-processed. You have been fortunate not to have gotten ill.

Dave


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RE: high seal failure rate

Ugh... I'm mad at myself because I've canned over 20 pints of tomatoes already and now I'm afraid to eat them! What a waste! Could they be good for anything? Like long-cooking stew recipes and such? I did notice the liquid inside the jars was boiling when I removed them from the canner (I realize that's not the most scientific way of knowing they are OK) but I have a feeling they might be.


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RE: high seal failure rate

Botulism is not killed at boiling temperatures. It takes at least 250 degrees (which requires pressure) for 3 minutes. Sufficient boiling will kill active toxins, so yes, long-cooking as long as at some point you achieve 10 minutes of boiling will take care of the problem.

However, it really depends upon your comfort level. If the product spurts when opened or you spill any and there's contamination, then there are additional issues.

It really is a kind of gamble. Depending upon their acidity, the size of container, the density and heat-penetration, your tomatoes may be fine. But the reduced processing time does introduce an element of risk.

Carol


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RE: high seal failure rate

Thanks, Carol. I'm so glad there are people out there who can give me guidance :)

So, let me get this straight.... boiling DOES NOT kill botulism? Then why is BWB canning good for anything? Is it just the acidity that keeps the botulism microbes from growing? It sounds like there is a lot more to home canning than I ever imagined.


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RE: high seal failure rate

So, let me get this straight.... boiling DOES NOT kill botulism? Then why is BWB canning good for anything? Is it just the acidity that keeps the botulism microbes from growing? It sounds like there is a lot more to home canning than I ever imagined.

Indeed there is more than many folks imagine.

BWB processing is strictly for high acid foods where the acid provides the protection, not the processing. BWB processing cannot be used for low-acid foods or for borderline foods - which is why the lemon juice has to be added to tomatoes.

As Carol said your tomatoes are risky - how risky depends on your personal level of risk tolerance and how they are used. Had you caught the problem within 24 hours you could have reprocessed them or frozen them. Now it is too late.

Technically speaking, from the guidelines POV, they should be disposed of, carefully and without question.

Personally, and totally unapproved, IF you added the required lemon juice or citric acid to them then I would salvage them. If you did not add the acid then I would dump them as they are much more dangerous as a low-acid under-processed product.

To salvage them I'd dump them all back into a big pot and boil them well for 15-20 mins. and then either pressure can them or run them through the tomato mill and cook them down into tomato sauce for the freezer. I would NOT leave them as is with the plan to use them later. I don't have that much risk tolerance. JMO

Dave


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RE: high seal failure rate

I see... thanks Dave. I did add the proper acid. I'm thinking I'll have to either salvage them as you suggest, or just boil the contents for 15 minutes before I use it in any recipes. Either way is kind of a pain, but at least I'll know better for next year, right? Thanks for all your help!


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RE: high seal failure rate

What many people don't realize is that boiling kills any botulism toxins which might have developed in the jar but not the botulism spores which produce the toxins. That requires pressure canning sufficient to reach the temperature and duration I indicated. Depending upon the density of the food, it may take some time to fully penetrate the center of the product and reach the desired temperature.

Botulism spores like low-acid, warm,(some exceptions depending upon the strain), oxygen-free environments.

So a sealed jar of say, green beans, processed in a boiling water bath would be a perfect candidate.

But raising the acidity, as Dave mentioned, removes one of the necessary conditions under which botulism spores proliferate.

It's not rocket science, but it's definitely a whole lot more complex than many recognize.

Carol


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RE: high seal failure rate

Perhaps to put this in perspective, botulism spores are everywhere, blow with the wind, land on your fruit and garden vegetables, yet they don't make people sick. The area around Utah and Western Colorado has a particularly high concentration of spores in the soil. We - us humans - very likely ingest / inhale spores constantly, yet the acidic nature of the digestive track prohibits the formation of botox, the stuff that's so dangerous.

As others have said, heat will destroy the toxin. Acid prohibits the formation of the toxin.

The problem for me is when people confuse the USDA's position of "if you process them this way for this long, you are absolutely, positively certain not to get sick" into "if you don't process them this way for this long, you are absolutely, positively certain to get sick".

So its a question of acceptable risk. I, personally, water bath can tomatoes for 20 minutes and use them in stews, soups, etc. - a heating process which, after opening the can, would destroy any possible botulism toxin.

as per the CDC: Despite its extreme potency, botulinum toxin is easily destroyed. Heating to an internal temperature of 85°C for at least 5 minutes will decontaminate affected food or drink. 85C = 185 F - eg a simmer.

Given the abundance and ubiquity of botulism spores, you'd think people would get sick far more often. But they don't - again because of cooking food and the acidic nature of our digestive tracts.

Here is a link that might be useful: link to CDC site


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RE: high seal failure rate

The problem for me is when people confuse the USDA's position of "if you process them this way for this long, you are absolutely, positively certain not to get sick" into "if you don't process them this way for this long, you are absolutely, positively certain to get sick".

No one here says that David. What is said is that if you don't process them as recommended by the guidelines then the risk of toxicity is increased and that you have now sealed the spores into the perfect environment for their growth, something they cannot do floating around in the air. And often added - that you have to determine the level of risk you are comfortable with.

I, personally, water bath can tomatoes for 20 minutes

If you are comfortable with processing them for only 25% of the time called for in the guidelines and you are comfortable with the risk that approach creates then that is your choice. But it isn't something to be advocated to others.

And I'm compelled to ask why 20 mins? Why not 10 mins. or 30 mins. or 45 mins. or 85 mins.? In other words why makes your choice of 20 min. processing time anything other than a totally arbitrary choice?

Dave


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RE: high seal failure rate

"....that you have now sealed the spores into the perfect environment for their growth"

We disagree: I don't consider a jar of acidic tomatoes with added acid a perfect environment for the creation of botulism toxin.

I water bath can tomatoes, tomato sauces, salsa, catsup, pickles, apple sauce, and pretty much everything suitable and recommended - eg acidic - for water bath canning for 20 minutes because the contents are boiling when I remove them from the bath, and I get a good seal.

I make an exception for pickled okra, if I water bath that for 20 minutes, I end up with slimy glop. I do that, in pints, for 10 minutes.

As many of the forum threads on this subject have noted, at unpressurised temperatures, you can boil botulism spores for hours and not destroy them. You need pressure canning and 250 F temps to destroy the spores. The toxin, how ever, is easily destroyed with a few minutes of simmering temps.

Out here in the west where the soil concentration of spores is so high, its windy, dry, and dusty, that those spores are very likely sneaking into a fair amount of everything I eat and can, no matter what precautions I take.


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RE: high seal failure rate

I was answering a general question about botulism. No knowledgeable person would consider an acidic product (including tomatoes with citric acid or lemon juice) as susceptible to botulism.

In an earlier response to the poster, Dave said that if the tomatoes had been amended with acid per recommendations he also would use them.

It doesn't sound as if anyone is in disagreement in that regard.

Carol


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RE: high seal failure rate

Just an update:

I canned 14 pints of crushed tomatoes today per the NCHFP instructions and all but ONE of them sealed. Kind of a bummer, but maybe it was just a fluke. I did tighten the lids just a little bit more than I've done in the past. One thing I've noticed is that the lids seem to take a few minutes to seal after I remove them from the canner. Is that normal? It seems like with the other things I've done (jams, salsa, etc.) the lids seal almost immediately upon removal from the canner.


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RE: high seal failure rate

Yes, it's totally normal for some foods to take longer to seal. The headspace, the size of the container and the density of the product can all play a role, so I don't see anything abnormal about a few minutes or even an hour.

Carol


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