Mortgage lifter and Rutgers were just as describe for me last year, awful. Brandywine, on the other hand, saved the season. I have no clue as to the cause but there is nothing worse than a grainy tomato.

You are right. My 9 year old son commented on the tomato nastiness this morning. It's that bad.

Did you have cold and wet weather while fruits were developing? I figure if I had a cold, wet stretch back in May, you probably did, too, except your tomatoes were probably fruiting already, unlike mine, which were much younger. Folk wisdom has it that cold and wet weather makes for mealy tomatoes, from what I understand.

Cool, wet weather is my guess. I have had this happen before and it will effect some more than others and should get better as the year goes.

Nothing but scorching heat for my tomatoes last year.

Also leaving on the plant til dead ripe.

I planted out April 29th, which was colder and wetter than normal. May was normal weather. So maybe only the first few fruits will be like this. i will update as time goes on.

I usually harvest so that they need one or two or three days of counter ripening.