Answer: According to the University of Minnesota Extension, "a lot of misinformation has been printed in the popular press about "low acid" tomatoes, referring to those with a sweet, non-tart taste. These tomatoes are often white, yellow, or pink in color but are not low in acid content. The higher sugar masks the acidic flavor."
The goal, then, might be to find a relatively low sugar tomato, rather than a high acid one. Some people say that the older varieties of tomatoes--the "heirlooms"--have the best taste (examples include Amish Paste, Mortgage Lifter, and Black Krim.) And I've noticed that yellow, orange, and pink varieties are often described as mild-flavored. So you might want to try a few plants of some of the older varieties, especially those described as having deep red fruits, and do your own taste test. I suggest you also plant at least a few of the newer, disease-resistant hybrids as well, because the old varieties are often susceptible to common tomato diseases.
Q&A Library Searching Tips