Jet Star and Ace 55 have a pH that requires addition of acid (vinegar or lemon juice) to safely home can even when full ripe.

The pH differences between "low(er) acid" Jet Star or Ace 55 and other "full acid" tomatoes is very slight however.

Click on this link:Korney's Acid Test and scroll down the page until you see a chart provided by Korney showing the Brix and pH measured in some common heirloom type tomatoes.

And you can see from Mark Korney's chart that there's really no major difference in acidity with those shown and if you were to go Googling you wouldn't find anything much different.

But so often at some seed sites you'll see this or that variety still being said to be low acid b'c for years many assumed that especially the pastel colored varieties did have low acid.

Not true. They have about the same acidity as others, it's just that a higher sugar concentration masks that normal acidity so they appear to be lo acid when eaten.

I wonder why your MD said only homegrown and while it's not my place to ask why the suggestion to eat only lo acid tomatoes, I would assume that there are other items normally eaten that are more acid ( as determined by actual pH values) than tomatoes.

Carolyn, who notes that taste perception is one thing but a pH meter is quite another.

rivkadr

Who told you to eat only "low-acid" tomatoes? A physician?

There really aren't any "low-acid" tomatoes except a very few that others may mention or list, and the difference is so slight, I really wonder if it even matters. Take a look at Korney's list. Just eat fewer of those you really like if they're higher-acid than the others!

Thanks for the information, guys. The homegrown low-acid requirement is from ic-network.com (for sufferers of interstitial cystitis); my doctor is having me follow their diet recommendations. They're really just general guidelines; some people have issues with some foods and not others, but in general, we're supposed to avoid tomatoes. The food list does say that we can eat the homegrown low-acid ones, but it sounds like maybe the folks at ic-network don't know what they're talking about in that regard...