# Pressure Canner for tomatoes?



## lemonthyme7 (Jul 8, 2010)

I know that most people BWB their tomatoes but is there any reason I can not use my pressure canner? I guess I should be honest and say I have always used my pressure canner for tomatoes but am wondering if this is okay? I don't have a water bath canner although I do have a very large pot I could use if I got a rack for it. Is there a reason why the BWB would be better for tomatoes? I know they are one of the "acids" so they can be canned that way but do they HAVE to be? I love my pressure canner and prefer to keep doing it that way if it's acceptable. 
Thanks for your help!


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## judylou (Jun 19, 2009)

Pressure canning of tomatoes is the most recommended way to can them and many do the same as you. It is not only faster but per NCHFP results in a better quality and higher nutritional product. However please do note that adding the required acid is still recommended.

Pressure canning tomatoes: http://www.uga.edu/nchfp/how/can_03/tomato_water_pack.html


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## coalroadcabin (Jun 16, 2004)

judylou, I have a question regarding pressure canning tomatoes.

Do you know why they recommend adding acid to tomatoes when you pressure can - but not other non-acidic foods (like chicken, green beans, corn, etc)? Is there something in tomatoes that makes them especially prone to spoilage?


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## judylou (Jun 19, 2009)

Good question.  Yes, all the water in them. Even when pressure canned, with water based foods the pH in the jars doesn't remain stable. Over time on the shelf the water in the fruit leaches and dilutes the liquid and raises the pH into a potentially unsafe zone.


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## marinemomtatt (Oct 8, 2006)

Couple years back my MIL forgot to add Lemon juice to her Tomatoes, she wound up dumping out all the jars...now personally I'd just rebatched.


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## PrettyPaisley (May 18, 2007)

judylou said:


> Good question.  Yes, all the water in them. Even when pressure canned, with water based foods the pH in the jars doesn't remain stable. Over time on the shelf the water in the fruit leaches and dilutes the liquid and raises the pH into a potentially unsafe zone.


Would that be the same for other fruits, like apples? I have a lot of jars of applesauce, pie filling and regular apples that I canned last fall. I wasn't as scared as I am right now but I did follow the BBB for the recipes. Is there a way to safely consume these?


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## judylou (Jun 19, 2009)

> Would that be the same for other fruits, like apples? I have a lot of jars of applesauce, pie filling and regular apples that I canned last fall. I wasn't as scared as I am right now but I did follow the BBB for the recipes. Is there a way to safely consume these?


Not necessarily as the water level in the food/fruit varies greatly. ie: apples don't contain nearly as much water as tomatoes do, not by half. Tomatoes are a soft fruit, apples are not. Apples are an acidic fruit while tomatoes are a low acid fruit. See the differences?

However those unknown factors - how much water does it contain, what is the pH of the food, what amount of processing would be required for the density of the food, etc. - is why using only tested and approved recipes are recommended for canning use. Stick with approved and tested recipes and all the unknowns have been answered for you. 

Since you followed the instructions in the BBB then you need have no concerns, assuming intact seals. All recipes in the BBB as well as in the other USDA approved canning cookbooks are tested and approved recipes. Those that call for added acid require it, those that don't do not. 

Unfortunately there are also numerous unapproved canning cookbooks and potentially risky recipes on the market and on the web so it is to our benefit to use only the approved sources. That way there is no reason to be "scared" of home canning.


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## Sparkey (Oct 23, 2004)

"Over time on the shelf the water in the fruit leaches and dilutes the liquid and raises the pH into a potentially unsafe zone."

Do you have references of any USDA studies on this ?

Thanks !


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## Sparkey (Oct 23, 2004)

Question has been answered.


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## judylou (Jun 19, 2009)

Glad you found your answer.  

If you want more info you might want to review the publications on the NCHFP website on the listeria and the salsa pH stability studies as well as the studies done on low-ratio vinegar to water studies done on pickles published on the FDA website. It showed a steady rise in brine pH as the water in the cucumbers moved into the brine via osmosis.

In our MFP textbook there is also reference to the "Hurdle Concept in Basic Food Microbiology" so searching with that term might bring up some more info related to your question.


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## Osiris (Jun 9, 2010)

I've read that tomatoes have been so over-bred the acid has pretty much been bred out of them. Unfortunately. That could be wrong info, but it wouldn't surprise me.


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## PixieLou (May 1, 2010)

It's more of an issue that the tomatoes have been genetically engineered to create low acid varieties. So now we have some low acid varieties - such as the beloved san marzano sauce tomato. When they make up the canning recommendations for tomatoes, they assume that nobody knows what variety of tomato they are using, so the instructions are assuming that you are using one of the low acid varieties. But there are still plenty of "high acid" tomatoes out there. 

A while ago I saw somewhere a listing of the acidity of the different tomato varieties. I wish I had bookmarked the site.


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## coalroadcabin (Jun 16, 2004)

judylou said:


> Over time on the shelf the water in the fruit leaches and dilutes the liquid and raises the pH into a potentially unsafe zone


Guess I don't get why the water in tomatoes would raise the ph to a unsafe zone but a food that is _already_ in the unsafe zone (like chicken) doesn't need any acid? Doesn't really matter, I don't want to get sick eating my food so I'll add acid to my tomatoes. BTW, I'd prefer to taste tomato not lemon - where the heck do you find citric acid? I didn't see anything marked 'citric acid' in the canning supplies when I was at the store today. 




judylou said:


> Stick with approved and tested recipes and all the unknowns have been answered for you.


Not to nit-pick but I would add *current* to the "approved and tested".  I've been canning my tomatoes in a pressure canner for decades using the 'approved' method that came with my canner.......obviously things have changed since the 1980's - I had no idea that I needed to add acid when I pressure canned!! It's a wonder I'm not dead, huh! LOL!


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## PrettyPaisley (May 18, 2007)

I canned tomatoes a couple of years back and used lemon juice as instructed in the Ball Book. I did not taste lemon at all when I cooked them. No sure why-since the Pomoma's pectin is so citrus-y to me, but with the tomatoes you would have never known there was lemon in it.


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## coalroadcabin (Jun 16, 2004)

PrettyPaisley,
That's good to know. Lemon _anything_ makes me gag. Maybe I'll try one batch to see how I like it. Unfortunately, if citric acid is the same as those nasty vitamin C tablets Mom used to make us chew......then I'm probably going to have to just keep canning my tomato sauce without additional acid and take my chances - I'm hoping that isn't the case.


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## judylou (Jun 19, 2009)

> Guess I don't get why the water in tomatoes would raise the ph to a unsafe zone but a food that is already in the unsafe zone (like chicken) doesn't need any acid? Doesn't really matter, I don't want to get sick eating my food so I'll add acid to my tomatoes. BTW, I'd prefer to taste tomato not lemon - where the heck do you find citric acid? I didn't see anything marked 'citric acid' in the canning supplies when I was at the store today.


In theory, if you wanted to pressure can your tomatoes for as long as you have to pressure can chicken then you wouldn't have to add the acid. But the tomatoes, since they are so soft to begin with, would be nothing but scorched tomato soup. 

The acidification requirement is the research team's way of combining safety with a still desirable end food quality.

Citric acid is readily available online at many sources that sell canning supplies for those who can't find it locally. Health food stores carry it according to many and here it is sold under the Mrs. Wages brand in the canning section of most all grocery stores, even WalMart but that varies from region to region depending on the demand. You can order it from the Mrs. Wages website or check out: http://www.google.com/webhp?hl=en#hl=en&source=hp&q=citric+acid+where+to+buy&aq=3&aqi=g10&aql=&oq=citric+acid&gs_rfai=CqsrGKCdUTOqAIJHuzAS5-7T0DwAAAKoEBU_QMJjP&fp=862314fdc3c7ad5 for many other online sources.

And I agree with you that *current* should be added to the "approved and tested".


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## lemonthyme7 (Jul 8, 2010)

Thanks for all your replies. Glad to know that the pressure canner is fine. Guess I should start adding acid to my tomatoes though. I have never added the acid and have never had a problem, but since I don't want to have a future problem it is a small correction just to be safe. I do raise mostly heirloom tomatoes so maybe they are more acid to start with?


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## bluebird2o2 (Feb 14, 2007)

I have an old canning book it doesnt say too add anything too tomatoes but salt.I avoid pink and yellow tomatoes as they are said too be low acid.I use old varietys and i boil the tomatoes for ten minutes after opening.i use the boiling water bath method.i think if you grow it yourself you ought too know what kind they are.


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## judylou (Jun 19, 2009)

> I do raise mostly heirloom tomatoes so maybe they are more acid to start with?


I think in general they may be but it is important to keep in mind that soil pH plays a major role in determining the pH of your tomatoes and some studies show that even the pH of your water can affect the pH of the tomato fruit. So even the same fruit grown in different gardens can have a different pH.



> I have an old canning book it doesnt say too add anything too tomatoes but salt.


Which is one reason why using only current books and guidelines is recommended. Thanks to ongoing research, things change and the acidification of tomatoes requirement was first discussed in 1968 when vinegar was recommended and changed to citric acid or bottled lemon juice in the 1976-78 set of major revisions. So it has been around for decades. Your book must be a very old book indeed. Might be time to consider investing is a new one.


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## FrontPorch (Mar 27, 2008)

So, I'm thinking the little book that came with my harvest gold canner should be tossed, yes?


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## judylou (Jun 19, 2009)

Not tossed but not used as a source of canning instructions for sure.  

The manual is great for learning how to use your cooker/canner but are never recommended as a reliable source for canning info. Especially when so much more reliable and current info is readily available. They don't claim to be a canning authority and most all of them include a referral to USDA/NCHFP for current canning instructions and processing times.


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## Paquebot (May 10, 2002)

Forget just about everything that's been "heard" about acidity having been bred out of tomatoes. Hasn't happened. What did happen was the Brix rating went up. That means more sugar. Many yellow and white tomatoes have more acid than their red counterparts but the higher sugar content masks the acid. Few tomatoes ever were really safe to can according to the standards set in the past 20 or so years. I've grown a few and most are "spitters". That is, one bite and you spit it out! 

Martin


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## oneokie (Aug 14, 2009)

Paquebot said:


> I've grown a few and most are "spitters". That is, one bite and you spit it out! Martin


Is that due to the higher acidity or to the higher sugar content?


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## Paquebot (May 10, 2002)

oneokie said:


> Is that due to the higher acidity or to the higher sugar content?


Neither, it's from lack of sugar.

I knew that a friend posted a brix and acid chart on Gardenweb a few years ago and found it. If 5.0 is the safe line for acidity, there were none. Check out the chart and it will cause you to wonder about what just a little more sugar will do to the taste buds. Example: Reisentraube with 7.15 brix rating and 4.50 acidity vs Yellow Pear with 6.53 brix and 4.36 acid. Everyone who has grown and tasted both know that Yellow Pear is sweeter than Reisentraube but that 0.14 difference in acidity cancels out the higher sugar content. 

http://forums.gardenweb.com/forums/load/tomato/msg081645247923.html 

Martin


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## SueMc (Jan 10, 2010)

> It's a wonder I'm not dead, huh! LOL!



Me too! I guess I am now my grandmother saying "I've always done it that way..." :kiss:

I've canned tomatoes with my pressure canner per old (30+ yrs) instructions:
exhaust canner, place weight (15#), and turn off heat when weight just begins to rock.
I never canned yellow tomatoes or salsa without added acid. I usually do follow new recommendations for canning but really wonder if ALL the "old" instructions are necessarily wrong. Sometimes I wonder if some of the new recommendations are overkill for whatever reason (liability of those who make the recommendations?)


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## Sparkey (Oct 23, 2004)

We freeze the 'better' tomatoes ( for making chili & spaghetti sauce on days when the snow flies  ) & use the 'good' ones for juice. Yesterday we pressure canned 29 qt. of juice @15 lb. pressure for 10+ minutes. 
Our favorite "mix" is to add a generous teaspoon of horseradish to the qt. jar of juice, a teaspoon of onion &/or garlic powder, 1/4 tsp. of cayenne powder or tabasco sauce, shake & let set for a while & serve with some crushed ice in a tall glass..... A real eye opener !

Charlie


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