No. Fruit Fresh is for color protection (anti-oxidant). It can't be used to acidify.

You can use citric acid or at a pinch vinegar, but vinegar has a detrimental effect on the flavor. Proportions at the link.

(It doesn't matter if they're yellow tomatoes or red; the only difference is the color in the jar.)

Carol

Here is a link that might be useful: Standards for Acidifying Tomatoes

As mentioned in many recent posts, ascorbic acid (Fruit Fresh and other brand names), cannot be a substitute for true an acidifer. Either granulated citric acid or bottled lemon or lime juice can only be used. Fruit Fresh is only used to prenet oxidation of the fruits. I also use it in pickled mushrooms and they remain a lighter color than without it.

Sorry Edie but you need to go get some lemon juice. Yellow tomatoes are often even lower acid than most reds.

Dave

I was afraid of that. Drat. It's 1/2 hour to the nearest store... OK, it's off to town with me. Thanks so much for all your help, I really do appreciate it.

Yellow tomatoes are often higher sugar but they aren't lower acid. Color is no indicator of acidity.

Carol

Color is no indicator of acidity.

True Carol, but several of the most common yellow varieties do, in fact, have a higher pH on the tomato pH scale.

Dave

Higher pH means less acidity!! The addition of an acid is very necessary in all kinds of tomato based canning. If there is an Indian food store near you, they sell citric acid, so its easy to find it, provided you look or call and ask.

Higher pH means less acidity!!

Yep. Exactly my point. ;)

Dave

My googling turned up the following amusing result:

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* Posted by digdirt 6 AR (My Page) on
Tue, Aug 14, 07 at 17:50

Has tomato acidity and/or flavor changed over the years?

Some of the "new" hybrid taste less acidic but based on all my reading that is supposedly due to the increased sugar content rather than actual lower acidity.
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Dave, was there specific info that changed your mind? The thread where I found this (linked below) has a pH table for different varieties (as well as some non-standard and potentially unsafe advice from other people who don't acidify tomatoes OR salsa!).

More importantly...I would bet that variation in the pH of a given type of tomato, based on growing conditions, is almost as great as the variation in the pH between different varieties of tomato. Statistically speaking, I would expect the effect size to be small (look up Cohen's d to learn more about the concept of effect size). No evidence, just an intuition, and I'd love to find some research on it. If only there were a scientific journal on canning, or at least canning papers in a peer-reviewed journal!

Melissa

Here is a link that might be useful: tomato forum discussion

Yes, Dave. Some of the common red varieties do also. I think we're back where we started, LOL.

Carol

pH values can vary greatly, not just by the type of tomato, but climate conditions, soil conditions, fertilizers, and many other factors, including locations, sunlight, shade, watering. Even from plant to plant and year to year they can differ in pH. Hybrids, heirlooms, big, small, plum, paste, beefstake, and so many varieties and even colors, that you can never depend on the natural pH of a tomato product, even from batch to batch. Suffice to say the discussion can continue, but there is no way that anyone can simply determine how much acidity there is in a tomato, or anything they are made into using current home canning methods.

Wow! Didn't mean to start a brouha! ;) Just to stress the import of using the required acid.

But discussing the acidity of a tomato in the context of taste as was the case in the quote above and in the context of canning are 2 very different situations. Numerous 'acid taste' discussions come up on the Tomato Forum. Can one taste the differences in acidic pH? NO. Can it make a difference in canning? Possibly if one is doing whole jars of yellow tomatoes and IF they are one of the higher pH varieties. But if you add the required acid to the jars then it is a moot point.

The pH range of all tomato varieties is very narrow - something like 4.3-4.9 so no we aren't talking a huge diff here and it is very true that growing conditions can change the end pH of the fruit. But yes, there are charts of tested tomato pH's on the web - posted here in the past and in the full discussion that is linked below. But based on those tests and the obvious limitations of them, only a few reds (most commercial) fall into the highest range while several yellows do - again based only on the test results of a specific set of growing conditions so your results may vary. ;)

And that variance is yet another reason that the acid is required.

Dave

Here is a link that might be useful: Tomato Acidity

Ok, so if I canned tomatoes w only salt, can I re-can them, or are they wasted?

<Ok, so if I canned tomatoes w only salt, can I re-can them, or are they wasted?>

It is your choice. Some who are willing to take the risk just use them as is. If you want to abide by the guidelines and have no risk then they can be re-canned within 24 hours. Otherwise they have to be boiled for at least 10 mins. before consuming.

The boiling will kill any toxins that have developed. But with no added acid they wouldn't be considered safe to eat without boiling them first.

Dave