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Pressure Canning Tomatoes

Posted by lyndapaz PA (My Page) on
Sun, Sep 21, 08 at 23:01

I've looked everywhere but can't find an answer to this question. Since pressure canning is required for low acidic foods, can I assume that I can pressure can tomatoes without added acid from lemon juice or vinegar? Everything I read says to add the acid, but I don't understand why, when I can pressure can corn or green beans that have little or no acid. If I don't add the lemon juice, should I pressure can for a longer time than what is recommended? I ask this because I just finished a batch of tomato juice and forgot to add the lemon, but I used a pressure canner maintaining the required pressure for 15 minutes. Thanks in advance for your thoughts.


Follow-Up Postings:

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RE: Pressure Canning Tomatoes

Oh, my gosh. We have discussed this so many times.

The acid needs to be added because that makes it possible to keep the processing time short for optimal quality.

With corn or green beans the processing time is going to be long regardless, unless you added so much acid it would impair flavor. So they're canned without it.

Carol


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RE: Pressure Canning Tomatoes

Lynda, as Carol says, without acidification the processing time would be much longer (no time has been published for that so there's no way to know how long). Since you finished within the past 24 hours, you can open the jars and reprocess. It sucks but it's the only way to know for sure that your product is safe. The danger with under-acidified products is botulism, which is the one food-borne illness that actually scares me, so if I were you I would reprocess. Sorry. :-(

Melissa


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RE: Pressure Canning Tomatoes

Looks like no tomato search was done.. Its always going to be a number one question, no matter what I guess. Lemon juice, lime juice (both bottled types), or granulated citric acid are very necessary. Even without them and pressure canned, you still risk safety. I prefer the citric over a juice. Its just tasteless sour acid with no flavor of its own. I add that to each jar just prior to filling. In this way I am assured that each jar has the proper amount. Its sometimes difficult to figure out how many quarts or pints you are making, so a total meaurement of even salt and citric can be way off if the tomatoes are less than a measured amount. Simply boiling the tomatoes can reduce liquid greatly, and if it also has salt and citric, they will get stronger when the water is boiled out. I do not think the 15 minute pressure canning is enough.


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RE: Pressure Canning Tomatoes

Everything I read says to add the acid..

And everything you read here will say the same thing. ;) The "why" only becomes a question when you try to "compare apples to oranges" or in this case, corn to tomatoes. Very different foods with drastically different pH.

Your juice needs to be totally reprocessed and the acid added. And please keep in mind that it must be bottled juice, not fresh, if you use juice.

Dave


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RE: Pressure Canning Tomatoes

Thanks for all the help. I have researched canning for two years now, reading hundreds of sites and no where does it say why you have to add acid if you are pressure cooking, but everywhere it says that you have to use a pressure cooker when processing low acidic foods. That's why I thought there might be a way to pressure can tomatoes without adding lemon juice. Of well, I'm certainly glad I finally came to the right place. I'll reprocess today. After reading ksroges response, now I'm wondering - Isn't okay to just put the juice in the bottom of each jar, like a lot of the sites tell you to do? And you don't have to add salt, do you?


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RE: Pressure Canning Tomatoes

No, salt is optional. So is sugar that many add.

And yes, just add the juice to the bottom of each jar. 1 T per pint, 2 T per quart.

Dave

PS: If you haven't already explored it, check out the link below as it provides all the current guidelines.

Here is a link that might be useful: National Center for Home Food Processing


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Now I Got It

Thanks, now I'm good to go! I'll reread that site. Part of the problem is that there are so many people saying so many conflicting things that it's hard to put all the pieces together. I canned for years with my Mom and Grandmom and, of course, we didn't do any of this stuff. Just boil, fill hot jars and screw on lids. Surprise, I'm still here to laugh about it.


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RE: Pressure Canning Tomatoes

  • Posted by gran2 z5 INDIANA (My Page) on
    Mon, Sep 22, 08 at 10:25

Grandma would indeed by appalled by what we do now (and what she didn't do then) but the vegetables just aren't the same. Thanks to genetic engineering and newer varieties, our tomato varieties have far less acid than hers did.


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RE: Pressure Canning Tomatoes

Here, when someone has an incorrect process or suggestion, it will always sbe corrected or expanded into a recipe that is usually perfectly safe to can. Fear not, we try to give accurate info here as much as we can.


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RE: Pressure Canning Tomatoes

I just processed tomato sauce without meat according to the directions of the National Center for Home Food Processing and it didn't require any addition of lemon juice or acid. The processing time is 20 minutes at 11 lbs of pressure. Now, why can't other tomatoe products, especially thoughs without added vegetables be processed for the same amount of time without added lemon juice? It just makes no sense to me.


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RE: Pressure Canning Tomatoes

Odd that no acid was mentioned. Its usually citric or bottled lemon or lime juice, (NOT fresh squeezed!). In all the safe, current tomato recipes I see, they all call for added acid, no matter if its tomato juice, sauce, puree, salsa, or other. The density changes when you add other vegetables. Most of them, like peppers and onions, etc, are low acid, and reduce the safety of the final product even more, so added acid is very necessary, as well as a longer processing time.


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RE: Pressure Canning Tomatoes

Again this very question has been discussed here SO many times that it is the one issue that I wish we could have a FAQ on. Invariably the person who learns they now have to add acid then discovers the spaghetti recipe and wants to know why it doesn't. ;) So if you want to read through additional discussions about it just do search.

The difference is this: what is allowed because of extensive testing in one recipe can never be transferred to any other recipe.

Once you accept that and the fact that you cannot can tomatoes with out adding acid then the "whys" become irrelevant to you and you can quit worrying about them. ;)

In this case the spaghetti sauce has been extensively tested over many years and found to hold its level of safety without any added acid needed. Part of the difference is because there is much less water in the spaghetti sauce than in plain tomatoes and because of the sugar which binds up much of the water in the recipe. Lastly the spaghetti sauce MUST be pressure canned will the plain tomatoes are optional.

On the other hand the plain tomato recipes have been repeatedly tested over many years and the testing shows the need for the added acid to maintain safe levels of acidity.

The spaghetti sauce recipe also allows for 1/4 cup of oil. Oil isn't allowed in much of any thing else so please don't assume that because this recipe allows it, it is ok to use in other recipes too.

OK?

Dave


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RE: Pressure Canning Tomatoes

Thanks for the explanation. I have always been one to question authority and have to be able to understand things on my own. I guess the only way that would happen in this case is if I start to use litmus paper and test the acidity of my products before and after processing (and potentially waste some good tomatoes). It's just so frustrating not being able to come up with rules that you can depend on rather than depending on someone else's conclusions without the benefit of the work that got them there. And why, I wonder, since so many people have this question has nobody done the research to say how you could process tomatoes in a pressure canner without adding the acid. If you can can meat that way, surely you can find the pressure and length of time necessary to process tomatoes that way. Sorry, I just find this very frustrating. But, don't worry, I'm not crazy enough not to follow only the approved quidelines. Thanks again for putting up with my questions.


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RE: Pressure Canning Tomatoes

And why, I wonder, since so many people have this question has nobody done the research to say how you could process tomatoes in a pressure canner without adding the acid.

Keep in mind we are dealing with a bureaucracy and an underfunded one at that. Safety is the focus and once that is established, they move on. ;)

Honestly, adding the acid is not a big deal for most of us since we have been doing it for 25 some years now. It only seems to bother those who are just discovering the rule. And most prefer the texture and color of the acid-added ones with the shorter processing time that allows over the texture and color you'd get from no acid and an excessively long pressure canning time.

Dave


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RE: Pressure Canning Tomatoes

Lynda, I agree that it's weird that tomato sauce requires lemon juice and spaghetti sauce doesn't. But to me, it does make sense. Notice that the "spaghetti sauce without meat" recipe says "Simmer uncovered, until thick enough for serving. At this time the initial volume will have been reduced by nearly one-half." This is a very important step. The thickening and the added sugar reduce the amount of water available, which makes the environment less hospitable to botulism. Also, the processing time would be 5 minutes longer at the same pressure (20 min at 10 lbs for spaghetti sauce, 15 min at 10 lbs for tomato sauce). That's not much but it does factor into the safety.

I am not recommending this, but I would think that in theory you could follow the spaghetti sauce recipe, leave out the other veg, and still process like spaghetti sauce, without lemon juice. The key requirements would be adding the sugar and salt as in the spaghetti sauce recipe, and cooking it down until reduced by half. Again, I don't know whether that's actually safe and I wouldn't risk it, I'm just trying to point out the big differences between the recipes that makes one not need lemon juice while the other does.

If the spaghetti sauce were not reduced to half its original volume, I wouldn't feel safe canning it without added acid.

As Carol said, in theory you could process plain tomatoes without acid, but you would have to can them so long they wouldn't be good. Don't ask how long, nobody knows. :-)

Melissa


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RE: Pressure Canning Tomatoes

But that's just it, Melissa. I used the plain sauce recipe which tells me to boil it down to desired thickness - either 1/3 to 1/2. I boiled it down to 1/2. But it still required me to add lemon juice and to process for 15 minutes instead of 20. Seems then like I could have processed for 20 minutes and skipped the lemon juice. And I wonder if the extra minutes aren't really because of all the alkaline veggies that are added to the spaghetti sauce. It just feels like it was just easier to keep all the recipes the same no matter which processing type you are using. But because you can't use a water bath canner with the spaghetti sauce they researched it differently. I like using the pressure canning method BECAUSE it has LESS processing time (and I believe the tomatoes taste better), using less energy, keeping the house dryer and cooler. I'm also particularly interested in leaving out the acid because I like to add milk when making some soups and sauces, but have found that I can't with any of the home processed tomatoes because of the addded acid. Maybe I can talk PA State Extension service into doing the research for those of us who really would like to have the answers to this dilemma.


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RE: Pressure Canning Tomatoes

Lynda, good luck. I haven't yet had anyone in "authority" tell me why I can pressure can tomatoes with okra or zucchini, the instructions from the NCFHFP says I can even add pearl onions, and pressure can, no additional acidity needed.

However, I can't can plain tomatoes for the same amount of time without the acid. Every single person I talk to says it doesn't make sense, but that it just hasn't been tested so they can't say it's OK.

I finally just gave up asking the extension service, or NCHFP, because they are underfunded and don't really do a lot of additional testing to answer specific questions.

I've learned to just take it on faith, and do what I think is the safe thing to do.

Annie


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RE: Pressure Canning Tomatoes

Back in July when this question came up again I wrote to Dr. Elizabeth Andress at NCHFP and asked for clarification. This is the answer I got.

Thank you for visiting the National Center for Home Food Preservation.

> question -> When pressure canning plain tomato products, why is acidification still required when it is not required for other pressure canned vegetables that are less acidic than tomatoes?

Thank you for checking. This is the statement about acidification on our website, below. The last sentence notes that the BWS and PC process times are equivalent:
If a procedure from the USDA Complete Guide to Home Canning for canning tomatoes offers both boiling water and pressure canning options, all steps in the preparation ("Procedure") are still required even if the pressure processing option is chosen. This includes acidification. The boiling water and pressure alternatives are equal processes with different time/temperature combinations calculated for these products.
http://www.uga.edu/nchfp/how/can_03/tomato_intro.html

In other words, the pressure process times are the equivalent to the boiling water heating; these pressure processes are not botulism processes like are calculated for low-acid foods. In a similar vein, there are pressure processes for many of our fruit products, but they are not botulism processes simply because they are in a pressure canner. Those are the equivalent to the acid processes in a BWC for each of those fruits.

You can use a little bit of acid in tomatoes to keep the process heating shorter like boiling water, which helps preserve quality and nutrients. It would take enough acid to create a pickled product for lower the other vegetable pHs to a boiling water-safe level. Non-acidified pressure processing times for tomatoes would most likely be longer than those we published as boiling water equivalents.

I hope this helps; I am not sure how many more ways to say it! let me know if this doesn't do it.
Elizabeth Andress
--------------------------------------
Elizabeth L. Andress, Ph.D.
Project Director, National Center for HFP
Professor and Extension Food Safety Specialist
Department of Foods and Nutrition
The University of Georgia
208 Hoke Smith Annex
Athens, GA 30602-4356
Phone: (706) 542-3773
FAX: (706) 542-1979

-----------------------------------------------

I'm also particularly interested in leaving out the acid because I like to add milk when making some soups and sauces, but have found that I can't with any of the home processed tomatoes because of the addded acid.

Why not? We use milk to make tomato soup out of our canned sauces and they have the lemon juice added.

Also keep in mind that likely there are folks that can their tomatoes without the the added acid either because they don't know about it or they just refuse to do it because Grandma never did it. So even though it isn't considered safe, you always have that choice. Each of us has to decide for ourselves the level of risk we can live with.

Dave


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RE: Pressure Canning Tomatoes

This is an old thread. However, I still believe there has to be another answer. Everything I read--here and elsewhere states that acidification must be done to tomatoes to prevent the possibility of botulism. Is it not true that if you boil the contents of a canned product at least 10 minutes you will kill any possible cause of botulism? Also, most Italian cooks will tell you the best Sunday sauce is cooked for hours. There really isn't any taste problem to processing tomatoes for as long as necessary - 60 minutes-- or more if necessary. Nutrition value I can't comment on. But, I would rather give up the nutrition value to have a good tasting final product.
I do not agree that the taste of added lemon to tomatoes is acceptable-- it is quite dreadful! If my theory is incorrect, I would rather give up canning tomatoes, than eat the lemon flavored ones and I certainly don't want to jeopardize my family with bad canned food. Can anyone comment on this? Thanks


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RE: Pressure Canning Tomatoes

I wish somebody would comment on this!

I don't mind the lemon taste in the tomatoes but I do wonder why I can can tomatoes and zucchini together without lemon juice but I can't can zucchini alone WITH lemon juice.

I asked this question last year on here and got a variety of answers but I think most folks got quite impatient with my questioning of status quo and some got a little snippy. I even emailed the lady quoted above, the expert. She just kept giving me the same pat answer. I even asked her about a LONG processing time because I will puree the zucchini anyway to make a non-tomato sauce for my allergic son. The basic answer I kept getting was "it would make an unaceptable product" and I couldn't seem to explain that the product would be totally acceptable to me, I don't care if it's pure mush!

I wish somebody would just explain in a way that makes sense. I completely understand your frustration.

I just read on here today about canning the tomatoes ans zucchini so I'm going to do that and I'm going to add lemon juice just to be safe because if testing is so incomplete, how do they know for sure it is safe?

VG


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RE: Pressure Canning Tomatoes

Everything I read--here and elsewhere states that acidification must be done to tomatoes to prevent the possibility of botulism. Is it not true that if you boil the contents of a canned product at least 10 minutes you will kill any possible cause of botulism?

That is a misunderstanding. You are talking about 2 different issues - botulism spores and botulism toxin.

Pressure canning kills the botulism spores themselves. Pressure canning WITH added acid allows for a much shorter processing time and a better quality product than would be required if the acid was NOT added.

Canning without pressure canning (BWB) does not kill the spores. But with acidification it prevents the spores (which are still alive) from growing and producing the toxin that is a side effect of their growth.

It is the toxin, NOT the spores, that make us sick.

Cooking/boiling after wards destroys only the toxin that may have been produced. It does not kill the spores themselves.

Citric acid is the most recommended form of acidification since it imparts no flavor as lemon juice does.

I do wonder why I can can tomatoes and zucchini together without lemon juice but I can't can zucchini alone WITH lemon juice.

Again, 2 totally different issues. The processing time on tomatoes WITH zuke is much longer than just tomatoes themselves with acid. So the spores are killed.

Canning zucchini is a safety AND quality issue. If you want to can chunks of zuke with added acid you may just as you can use zukes in pickles. Plain chunks of zuke canned would be mushy so not recommended.

Pureed zuke is another matter - when pureed it becomes a density issue so not recommended because it would take so long for the heat to penetrate that what you get is scorched tasting zuke mush with a hint of lemon flavor. No one would want that so why would they ever take the time to test it.

The bottom line is that you both can do whatever you wish as no one is going to come and arrest you. ;) It just isn't 'recommended'. It is your time and produce and risks to take and if the end result is acceptable to you that is fine.

So leave out the lemon juice if you simply can't stand it for some reason and cook the heQQ out of it after wards if that is what you want to do. And pressure can your chunks of zuke with added lemon juice and puree it after opening if you wish.

None of us can tell you it is 'safe' or not because they are low-acid vegetables. It is your choice.

But you are both trying to squeeze a square peg into a round hole and that never works. So best solution is to just puree the zucchini or make the tomato sauce and freeze it. Then you'd have no concerns.

Dave


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RE: Pressure Canning Tomatoes

Thanks Dave!

I have frozen the puree but my freezer is full!

I would certainly can chunks and puree it after opening so the fact that it is lemon flavored mush doesn't matter. I add lemon juice to the frozen puree to make the "Untomato Sauce" for my son so adding it to the jars to can is not a problem.

So the botulism toxin is what makes one sick and the boiling in the pot does destroy the toxins. If the spores remain in the food, it would not create more toxins would it? Seems like I've read that it only produces the toxins in an oxygen-free environment, i.e. a sealed jar. Is that true? If so, the leftovers wouldn't be a problem? I do remember hearing about a man and his daughter who got botulism from eating foil-covered baked potatoes that had been left out on the kitchen counter overnight. I assumed the foil had kept the oxygen out.

I really appreciate the spirit of scientific inquiry. My mind just wants to get it all figured out. I have nothing against safe canning practices. I've been canning, following all the rules, for over 40 years and helped my grandmother before that. She followed all the rules at the time too.

Thanks again Dave

VG


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RE: Pressure Canning Tomatoes

The big danger in refigerated leftovers isn't botulism. There is usually too much oxygen present for that. The danger in leftovers is e coli which loves those conditions. Although it isn't deadly like botulism it can still make you mighty sick. It is the cause of so called "food poisoning" which hospitalizes many people every year. Picnics where food gets left too long in the sun are notorious for producing food poisoning. Ask any hospital doctor or nurse.


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RE: Pressure Canning Tomatoes

I am including the link for the tomatoes, okra and zucchini recipe from the NCHFP.

My understanding is that substituting a low acid vegetable with a higher acid vegetable is allowed and considered safe. If anything, keeping all other ingredients the same and using the same processing time would make the recipe even safer.

So I take the approved (safe and tested) recipe for okra, zucchini and tomatoes, and put more tomatoes in place of the okra and zucchini. Since the extra tomatoes are higher in acidity than either zuchs or okra my overall pH should actually be a little lower than the original recipe. So now I have my canned tomatoes safely processed in a pressure cooker for 30 or 35 minutes at 11 psi. I can live with that.

OK, now I take Linda Lou's tomato soup recipe. This is to be pressure canned for 20 minutes at 11 psi. I actually use more time because I don't want to process twice for just a few pints, but it should work with the minimum of 20 minutes. I have recently made the recipe for soup just as it is (with only a 1/4 of the sugar though!) and it is delicious. But sometimes I want just plain sauce, not soup. So I take this recipe, and I substitute more tomatoes for the onion, red peppers, carrots and celery. No sugar. I do add salt (not needed for safety, just a personal preference). Now I have plain canned tomato sauce, which I can flavor upon opening, with some onions, garlic, white wine, herbs, olive oil, olives.....you name it.

So this is how I am safely making tomato chunks and tomato sauce, using my pressure canner and adding no acid.

I do not want to add acid simply because I am a snob. I have grown them little babies from seed which I have purchased, traded, or received as gifts. They are so delicious just as they are! Adding 'bottled' lemon or lime juice, or citric acid, or any acid is not acceptable to me, because it will affect the flavor of my precious home grown heirloom tomatoes (I told you I was a snob). I think with the method I described I take care of the safety issue, and others might want to do it too. If there is any flaw in my reasoning, please let me know.

cabrita, the tomato snob.

Here is a link that might be useful: tomatoes okra and zucchini


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RE: Pressure Canning Tomatoes

So this is how I am safely making tomato chunks and tomato sauce, using my pressure canner and adding no acid.

Well that is how you are making them and it is of course your choice. But whether they are safe or not, no one can say. For one thing, the issue of density would need to be factored in to compute the required processing time. Processing them for 2x as long as required may be enough but no one knows. Second concern is the long-term shelf stability of their pH.

With your canned tomatoes the only pH control in the jar is the pH of the tomatoes to begin with. Since all varieties are borderline and some varieties are well over the line at 4.7-5.0 that pH is in question to begin with.

Further, since pH rises over time, even if the pH of all your tomatoes were less than 4.6 it wouldn't remain so. But with the added acid, long-term pH stability is not a concern since the pH of the recommended additives is stabilized.

Your choice but not recommended as safe.

Dave


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RE: Pressure Canning Tomatoes

That is a misunderstanding. You are talking about 2 different issues - botulism spores and botulism toxin.
Pressure canning kills the botulism spores themselves. Pressure canning WITH added acid allows for a much shorter processing time and a better quality product than would be required if the acid was NOT added.
Canning without pressure canning (BWB) does not kill the spores. But with acidification it prevents the spores (which are still alive) from growing and producing the toxin that is a side effect of their growth.

Dave, thank you for your response - and your clarification of spores vs toxins. I know I am "beating a dead horse". But, in reading your response, perhaps you misunderstood what I was saying.

I only pressure can fresh tomato sauce ( puree and basil)- I do not use BWB. I am willing to pressure can as long as necessary to produce a safe product without added acid. I don't care how long the process time is and the "product" will be a much better quality for me if it does not contain any added acid. I would happily cook down the "sauce"if that was the only alternative. I just wish there was some difinitive time - i.e. 40 minutes, 60 minutes etc. in the pressure canner that someone could give me.


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RE: Pressure Canning Tomatoes

Ladylyn, per my previous post, I use the same as the okra, zucchinis and tomatoes recipe. 30 or 35 minutes at 11 psi (if you are under 2,000 feet) is what I use. I use this for my tomato sauce, and tomato chunks without added acid.

Dave, there is no reason that the pH would become unstable with all tomatoes, but be stable with mostly tomatoes plus some zucchinis and okra (approved pressure canning recipe). Sorry, but this does not make sense. Same with your argument on the density. The density of the sauce was exactly the same as the density of the soup (I measured it).

Ladylyn, they do not want to give processing times for tomatoes in pressure cookers because a lot of folks feel that long pressure cooking degrades the product. If you feel like I do, that you'd rather pressure cook a little longer than add acid, the link I provided gives you the approved cooking time. The substitution that I made is one that is considered safe, so I am not sure what the problem is.

There was an old thread I had started on this topic, and the conclusion was that one way around this acid issue was to use the recipe I linked above. It was NCHFP approved with safe substitutions (no substitution really, just leaving the okra and squash out).

I do agree with Dave that the choice is up to every one of us. I have read a lot about this dilemma, and have made the choice to pressure can tomatoes without acid. I use 11 psi for 30 to 35 minutes because it is the closest recipe that the NCHFP lists. The recipe that the NCHFP lists has lower acidity than my mix (tomatoes, zucchinis and okra vs. just tomatoes and salt) so I feel that by using their processing pressure/time I err on the side of over-processing, if anything. I feel this is safe enough to feed the products to my family. You need to understand the risks and make your own choice, of course!


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RE: Pressure Canning Tomatoes

after 30 years i am thinking of canning again. i wish i had kept the jars and equipment that i'd gradually shed. people in this thread are talking about 11 psi. but the newer pressure canners with weights are for 5, 10, and 15 psi. is 11 psi a new standard ? and how would you achieve that with weights ?
also, if i can only heirloom tomatoes in a bwb, and my pH color strips read under 4.5 for the cooked tomatoes, my sense is that i don't have to add acid. i work in a lab and the pH strips are accurate for solutions and buffers, even ddH2O. any chemists out there, or comments from someone who might know more about this ?
someone mentioned the pH in the jars changing over time. if the spores are killed with proper pH and canning times- well, dead spores won't grow no matter what the pH becomes.
thanks ! pattypan


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RE: Pressure Canning Tomatoes

The 11 lb. requirement is a relatively new requirement but is only attached to dial-gauge canners and is due to the now-established gauge inaccuracy. The instructions when using a weighted canner is 10 lbs. or 15 lbs. according to altitude.

Heirloom tomatoes are no more or no less acidic than non-heirloom varieties. The pH assigned to any particular variety is totally dependent on where the particular tomato was grown and under what conditions as soil pH, water pH, and fertilizers used can all affect the pH of the resulting fruit.

The use of pH strips or pH meters is not approved in home canning because of the danger of false positives. It is an issue which is often discussed here.

As to pH rising over time, USDA/NCHFP research has well documented that to be the case and that too has been discussed here in great detail on numerous occasions. Accept or reject it as you wish.

However the reason it is an issue is due to the vagaries of human participation in the process, one cannot safely assume or even hypothesize that all the spores are killed.

Everyone has the option of accepting and abiding by the published guidelines and the science behind them or ignoring them. It is their risk to take.

However, given the ease of following the guidelines and the minimal, if any, change they make in the product, and the readily available alternative of citric acid to the lemon juice, it defies common sense to ignore them.

I only pressure can fresh tomato sauce ( puree and basil)...I just wish there was some difinitive time - i.e. 40 minutes, 60 minutes etc. in the pressure canner that someone could give me.

There is none. Not without the acid. You can do as Cabrita suggested and use the processing time for one of the other tomato recipes if you wish. It is your choice. But there is no guarantee of safety attached to it. Have you tried using citric acid?

Dave, there is no reason that the pH would become unstable with all tomatoes, but be stable with mostly tomatoes plus some zucchinis and okra (approved pressure canning recipe). Sorry, but this does not make sense. Same with your argument on the density. The density of the sauce was exactly the same as the density of the soup (I measured it).

Cabrita - it may not make sense to you but it is the position of NCHFP currently. Whether that is because the tomatoes plus zucchini is one of the very old carry-over recipes that has never been upgraded or what, I can't say. Dr. Andress at NCHFP could likely explain it better than I anyway.

But as I said above the choice is yours as long as you understand that it wouldn't be approved as safe and IMO shouldn't be advocated as a "safe" alternative to others.

Dave


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RE: Pressure Canning Tomatoes

I agree with Cabrita that her method follows NCHFP guidelines for canning tomatoes with a pressure canner without the addition of acid. NCHFP makes provisions for canning tomatoes and also has provisions for canning acidified tomatoes. Tomatoes and acidified tomatoes are not considered the same vegetable by the NCHFP.

Tomatoes are considered by the NCHFP to be low acid and must be canned in a pressure canner. Alternately acidified tomatoes are considered as acid and may be canned in a boiling water bath or a pressure canner.

From the USDA Principles of Home Canning

Although tomatoes usually are considered an acid food, some are now known to have pH values slightly above 4.6. Figs also have pH values slightly above 4.6. Therefore, if they are to be canned as acid foods, these products must be acidified to a pH of 4.6 or lower with lemon juice or citric acid. Properly acidified tomatoes and figs are acid foods and can be safely processed in a boiling-water canner.

To me it is clear that you have an option to can tomatoes as acid or non acid. To can as an acid food you must add acid.

As noted by Cabrita NCHFP provides for processing times for tomatoes in the tomato and zucchini recipe. There is also a PC processing time for tomato sauce in a pressure canner. The spaghetti sauce recipe can be modified by removing the low acid vegetables. No added acid is required in the spaghetti sauce recipe and it must be processed in a pressure canner.

In addition the NCHFP recipe for tomato paste requires no added acid and is processed in a boiling water bath.

Of course that is my intgerpretation of the NCHFP quidelines and everyone must read them and make their own interpretation.

Zeuspaul

Here is a link that might be useful: Principles of Home Canning


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RE: Pressure Canning Tomatoes

Good evening!
I am new to the site, but trying to get a good answer here. I just processed 6 jars of tomatoes and forgot the lemon juice. Can I just open them, add the juice, change the lids and reprocess... or should I just freeze these tomatoes instead? I guess I am looking for someone who has done this and knows it is safe :)

Heidi


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RE: Pressure Canning Tomatoes

Heidi - if less than 24 hours, yes, you can reprocess them. You can always reprocess with 24 hours. Or, and easier, just freeze them.

Dave


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RE: Pressure Canning Tomatoes

Sorry to revive such an old thread (although the last post wasn't but a few months ago), but it occurred to me that one MAY can tomatoes by the pressure method, using the mixed vegetables procedure. The procedure, itself, says you may change the proportions of the mixed veggies, and may substitute anything but leafy greens, dried beans, cream-style corn, winter squash and sweet potatoes. So, it seems to me that one could have a 100% tomato batch, and prepare and process per the instructions cited in the link below, and still be safe.

Here is a link that might be useful: NCHFP mixed vegetables instructions


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RE: Pressure Canning Tomatoes

but it occurred to me that one MAY can tomatoes by the pressure method, using the mixed vegetables procedure.

Sorry but I don't get it.

Why would anyone want to process them for 75 or 90 mins (depending on jar size) at full pressure when they can be processed for only 20 mins. at a much lower pressure (depending on altitude) if they used the standard tomato PC instructions?

75-90 mins. at 10-11 lbs. is going to result in chunky tomato soup.

Dave


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RE: Pressure Canning Tomatoes

Dave, you are right. The texture would not be something I would want, but there was someone upthread (vegangirl, I think) who said that she didn't care about texture, didn't care if it was mush. So, I figured this might be useful information for those for whom eating texture does not make a difference.


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RE: Pressure Canning Tomatoes

In our litigious society, there are no USDA guidelines to safely pressure can tomatoes without acid. Each of us has to use our brains and decide for ourselves what we personally will do. I, personally, tend toward the adjust safe recipes to only tomatoes and PC at that level for those tomato products to which I don't want to add acid. But I would never suggest anyone do this unless they are sure, for themselves, that it is safe, and have made that personal decision! Most tomato products aren't a problem for me with a little added acid. The tomato soup is an exception. For that, I use the tomato soup recipe from Linda Lou. I always can a few Spaghetti Sauce without meat(also with out everything else) to have at least a few jars of tomato sauce that has no extra acid. We all might just as well admit that until the USDA has the money and impetus to test PC tomatoes without acid, there will be no guidelines. At least we have gone beyond open kettle canning of tomatoes, which is how I grew up canning tomatoes. I remember, as a child, putting up 100 quarts of tomatoes a year without even BWB canning them. We even used flour in the tomato soup. Boy have things changed! I'm maybe lucky to have survived.


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RE: Pressure Canning Tomatoes

gardensewer, respectfully, that's my point. There IS an approved method: the mixed vegetables procedure. The procedure says:

"Selecting, Preparing and Canning Vegetables
Mixed Vegetables

* 6 cups sliced carrots
* 6 cups cut, whole kernel sweet corn
* 6 cups cut green beans
* 6 cups shelled lima beans
* 4 cups whole or crushed tomatoes
* 4 cups diced zucchini

Optional mix � You may change the suggested proportions or substitute other favorite vegetables except leafy greens, dried beans, cream-style corn, winter squash and sweet potatoes."

If you can have a small amount of tomatoes, and the procedure states that you can optionally change the proportions, then this, to me, implies that you can have up to 100% of any vegetable in that list, and process for the time required by the procedure, and still be safe.

While it is not something I would choose to do because of the reduced textural quality of the end product, someone WAS looking for a procedure for canning tomatoes without added acid. This is what I found.

Here is a link that might be useful: NCHFP mixed vegetables instructions


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RE: Pressure Canning Tomatoes

I don't believe I would want to can tomatoes for that long. I prefer to use the spaghetti sauce without meat recipe. Since we are changing things anyway and there really isn't a recipe for PC tomatoes, alone with no changes and no acid, we have to use what we as individuals choose. Until the USDA finds the money or is somehow forced to test and produce a recipe, we are forced to make these choices.


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RE: Pressure Canning Tomatoes

I agree. If one isn't concerned about texture, I can't think of a single rational reason why the time and pressure for mixed vegetables wouldn't be just fine.

I had said very early in this thread that adding acid makes pc-ing tomatoes for a lesser time possible, thus improving quality (including retention of nutrients).

From the perspective of the NCHFP (when it was funded), it was also easier/less expensive to extrapolate a PC time from the BWB testing data, which was with acid-amended tomatoes, than to start from scratch.

In many cases the NCHFP extrapolated from original USDA data. They didn't have the resources for anything else.

I don't choose to can my tomatoes "plain"; I am not bothered by citric acid and for a lot of reasons (including energy costss) I prefer a shorter processing time.

But if someone wants to use the time for mixed veggies, who cares?

Carol


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RE: Pressure Canning Tomatoes

I canned my own spaghetti sauce with ground beef and pork italian sausage a while back and it went well. So this time I did it again and used the citric acid. The jars are about a month or so old now, we opened one the other night and the sauce tasted sour. Does this mean it's bad? Should I throw the whole batch out? What could have caused this? I can't find any real info online.


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RE: Pressure Canning Tomatoes

I canned my own spaghetti sauce with ground beef and pork italian sausage a while back and it went well. So this time I did it again and used the citric acid. The jars are about a month or so old now, we opened one the other night and the sauce tasted sour. Does this mean it's bad? Should I throw the whole batch out? What could have caused this? I can't find any real info online.

I'm sorry but I don't think we can answer your question with any degree of accuracy. First because you apparently used an untested, unapproved recipe. That is something that is done-at-your-own-risk when it comes to safety issues and whether to keep it or not. First rule of home canning is that you shouldn't make up or use untested recipes so for that reason alone it may need to be tossed.

Second because we'd need much more information on the recipe itself, the specific ingredients and amounts, the density, the type of processing used, the processing time used, the size of the jars used, the amount of citric acid used, etc. etc.

While it is possible the citric acid caused the flavor change it is more likely that something else is the issue. One of the big advantages of using citric acid over vinegar or lemon juice is the fact that it normally causes very little if any flavor change when used in the recommended amounts.

Further, the tested and approved spaghetti sauce recipes don't call for using citric acid so I can't compare the taste to determine if the citric acid is the issue or not.

Sorry to be of so little help.

Dave


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