For several years now, I have put up stewed tomatoes in pint jars, processing them in a waterbath. This year, I have a lot more tomatoes than usual, so I decided to make a batch of Italian-style tomato sauce (I.e., spaghetti sauce).
I used 20 lbs of tomatoes which were peeled, seeded, & cooked down (with seasonings) to fill 7 pint jars. The jars & lids were sterilized for 10-15 minutes in a boiling water bath, then filled hot, and then processed in a boiling waterbath for 35 minutes. Once removed & cooled, they all had sealed well & looked delicious.
My question is this: Someone told me after I was done that I needed to add lemon juice to the sauce, and without it, the sauce would not be acidic enough to be properly preserved. I did not add lemon juice, and was under the impression that tomatoes were one of the few things that could be safely processed in a waterbath, due to their acidity. I am now, however, uncertain as to whether this sauce is unsafe due to the lack of lemon juice? I've never had trouble with the stewed tomatoes, but with the sauce, since the tomatoes were seeded, I wondered if maybe this reduced the acidity significantly?
I'd hate to discard so much hard work, but am at a loss for an answer. Any insight appreciated! Thanks,
Kirstin Larson
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jal_ut
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Tomatoes are one fruit that is borderline acidic, and different varieties vary considerably in how much acid is present and also the soil they are grown on has an influence. For many years now, it has been recommended that additional acid be added to tomatos for processing. Lemon juice, vinegar and citric acid are sometimes used.
If any low acid food is added to tomato products you further reduce the acid content. Please also note that there are new times for processing tomatoes.
I recommend that you use only approved recipes for all home canning. Approved recipes can be found in the Ball Blue Book or at your extension office.
Botulism is the risk if you can low acid foods improperly. Botulism is nasty stuff. It is not worth the risk in my book.
I am not going to make any recommendation about your spaghetti sauce.
Call your extension.
If any low acid food is added to tomato products you further reduce the acid content. Please also note that there are new times for processing tomatoes.
I recommend that you use only approved recipes for all home canning. Approved recipes can be found in the Ball Blue Book or at your extension office.
Botulism is the risk if you can low acid foods improperly. Botulism is nasty stuff. It is not worth the risk in my book.
I am not going to make any recommendation about your spaghetti sauce.
Call your extension.
I don't know the precise pH at which tomato purees and the like are considered sufficiently acidic to can by water-bath. No doubt your ag extension service will know! 
I can't remember where I read it, but somewhere in the past three to five years, I *finally* found an explanation of the recommendations to add lemon juice to (normally acidic, you'd think
) tomatoes when canning them:
Traditional, I.e., "heirloom" or "heritage" breeds of tomatoes were acidic enough to safely can using water-bath methods. Hybrid tomatoes, however, are usually less acidic for flavor purposes--more appeal to more people--and usually are *not* sufficiently acidic.
This does NOT mean, though, that heirloom tomatoes from one's garden are, ipso facto, safe simply because they're heirlooms.
Inquire about pH information and how to test/measure it. Again, your county ag. extension service will probably be the best source of information.
I've been freezing tomatoes, but this is a temporary dodge, because the freezer space is much more limited than the room-temperature or even cool spaces. All it will take is one good power outage....
Cynthia H.
Sunset Zone 17, USDA Zone 9
I can't remember where I read it, but somewhere in the past three to five years, I *finally* found an explanation of the recommendations to add lemon juice to (normally acidic, you'd think
) tomatoes when canning them:Traditional, I.e., "heirloom" or "heritage" breeds of tomatoes were acidic enough to safely can using water-bath methods. Hybrid tomatoes, however, are usually less acidic for flavor purposes--more appeal to more people--and usually are *not* sufficiently acidic.
This does NOT mean, though, that heirloom tomatoes from one's garden are, ipso facto, safe simply because they're heirlooms.
Inquire about pH information and how to test/measure it. Again, your county ag. extension service will probably be the best source of information.I've been freezing tomatoes, but this is a temporary dodge, because the freezer space is much more limited than the room-temperature or even cool spaces. All it will take is one good power outage....
Cynthia H.
Sunset Zone 17, USDA Zone 9
I read to add 1/4 tsp citric acid per pint regardless of the variety of tomato. Better too acid than not enough. About boiling times, for stewed tomatoes I did 85 mins; salsas get 30 mins; pasta sauce might have gotten 60 (?--don't quote me on that). If you use lemon juice, you have to use a ton, like 1/4 or 1/2 cup and that affects the flavor. So I just use citric acid.
I checked my Ball Blue Book (published in the late 90's so relatively recent). It says for seasoned tomato sauce in pint jars to use either 1 tablespoon bottled lemon juice or 1/4 teaspoon citric acid and to process them for 35 minutes. If you want to keep the sauce in jars rather then freezing it, you could reprocess it, just make sure to add the extra acid when you put the hot sauce back into hot jars. 
I just canned up 5 pints of straight tomatoes yesterday. I added 1 tablespoon of lemon juice to each pint and had to process them for 1 hour and 25 minutes because I packed them in their own juices rather then in water
(with water it would have been only a 40 minute process time). The rules of canning do seem crazy some times but we want to be safe so we do what's necessary.
I just canned up 5 pints of straight tomatoes yesterday. I added 1 tablespoon of lemon juice to each pint and had to process them for 1 hour and 25 minutes because I packed them in their own juices rather then in water
(with water it would have been only a 40 minute process time). The rules of canning do seem crazy some times but we want to be safe so we do what's necessary.-
jal_ut
- Super Green Thumb
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- Location: Northern Utah Zone 5
The reason for the addition of acid is to make certain that the acidity is high enough that botulism spores will not grow. Botulism will not grow in an acid environment. If the acid content is not high enough, botulism will grow and when growing in an anaerobic environment botulism produces a toxin which is deadly. (anaerobic = without oxygen, which is the condition in a bottle of canned food.)
Botulism spores are everywhere. You have to assume that you have some in any product you can. The boiling water method of home canning will not kill the spores. It will kill yeasts, and bacteria. To be safe your product must have enough acid in it.
Botulism spores are everywhere. You have to assume that you have some in any product you can. The boiling water method of home canning will not kill the spores. It will kill yeasts, and bacteria. To be safe your product must have enough acid in it.
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pharmerphil
- Senior Member
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- Joined: Sat May 02, 2009 7:13 am
- Location: Minnesota
Best advice that can be given jal_ut !jal_ut wrote:Tomatoes are one fruit that is borderline acidic, and different varieties vary considerably in how much acid is present and also the soil they are grown on has an influence. For many years now, it has been recommended that additional acid be added to tomatos for processing. Lemon juice, vinegar and citric acid are sometimes used.
If any low acid food is added to tomato products you further reduce the acid content. Please also note that there are new times for processing tomatoes.
I recommend that you use only approved recipes for all home canning. Approved recipes can be found in the Ball Blue Book or at your extension office.
Botulism is the risk if you can low acid foods improperly. Botulism is nasty stuff. It is not worth the risk in my book.
I am not going to make any recommendation about your spaghetti sauce.
Call your extension.
I have been canning for years, and I always, out of habit and for reference (getting feeble minded) , keep the Ball Blue Book out, and handy when canning.
The presence of sugar, salt, acid, etc. are all beneficial for increasing your odds of inhibiting bacterial growth in preserved foods. You would also have added protection if you refrigerated your home-jarred goods since the temperature danger zone for bacteria is between 40F and 140F. I personally know that tomato sauce freezes beautifully. So if you're just making tomato sauce, you don't need to preserve the sauce in a jar to store it in the freezer. Simply make the sauce, store in an airtight container and freeze.
However, if you wish to continue jarring, it would be wise to reference some books on the subject. An easy way to do this is to visit Google and enter the Books section at the top of the page. Type something like preserving tomatoes/sauce and the search engine will populate a list of books that you can reference to learn more on the subject. From here, you can read limited pages from the book(s) without ever renting or buying them.
If you follow stringent hygeine methods, contracting botulism is difficult to contract from preserved tomatoes, especially if they are preserved in a jar instead of a can. Since the botulism toxin is destroyed by high temperatures, home-preserved foods are best boiled for 10 minutes before eating.
However, if you wish to continue jarring, it would be wise to reference some books on the subject. An easy way to do this is to visit Google and enter the Books section at the top of the page. Type something like preserving tomatoes/sauce and the search engine will populate a list of books that you can reference to learn more on the subject. From here, you can read limited pages from the book(s) without ever renting or buying them.
If you follow stringent hygeine methods, contracting botulism is difficult to contract from preserved tomatoes, especially if they are preserved in a jar instead of a can. Since the botulism toxin is destroyed by high temperatures, home-preserved foods are best boiled for 10 minutes before eating.
Your nearest Extension Service office will probably have a Master Canner on staff. They are remarkably knowledgeable people, and they have all the latest information about safe canning techniques. Just find them in your phone book and give them a call. They'll be happy to answer any canning-related questions you may have. It's a free service, too!
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Gary350
- Super Green Thumb
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I have been canning tomatoes for 40 years and I never add citric acid or lemon juice. In the past I never added salt either but I did this year. Some canning books tell you to add acid but I don't recall if they tell you to do this for both water bath and pressure cook. I do pressure cook because it is faster and safer. Some years vegatables will get certain problems bactria or blite or something that low temperature water bath will not kill so I always do pressure cook. If you grew and canned low acid tomatoes adding acid would defeat the purpose of growing low acid tomatoes pressure cook would guarantee they will not spoil.