i don't have an answer but i have a similar problem. My big tomatoes [dont remember variety] have this they are grown in buckets with a mix of potting soil and garden soil with added continuous release fertilizer. Big gorgeous plants with ugly tomatoes. What is it???

It's the beginning stages of Blossom End Rot. The spot doesn't become sunken until later, when the fruit begins to ripen. Then the affected area not only becomes sunken, it also turns dry and leathery.

If it were Late Blight you'd also have black spots on the leaves and stems of the plant by the time you got fruits that looked like that.

One of my plants a few years ago also had almost every fruit affected by BER. None of the plants surrounding it had any BER at all. Weird.

That is not BER. Not sure what it is though. Maybe the results of sunscald.

Ummm. Yes it is BER. Just hasn't turned black as yet.

if you say so jean.

I also have blight/BEM - but only on 1 of 4 plants that are next to each other and close together. Any way to save any of the tomatoes on the problem plant? Can it spread to other plants? Should I just cut down the blighted plant? Had a similar problem last year with 1 of 6 tomatoes, checked soil at end of last growing season and beginning of this one and no measurable deficits. Fortunately, my sweet 100's and early girls are out producing anything I've grown in the past! Any ideas for solving the solitary blighted plant problem much appreciated.

This is most likely BER, besides - if it were indeed late blight, then it would be on the top of the tomato, not the bottom.