no, I did not know that: Calcium Chloride is added to diced canned tomatoes...


to keep them from breaking down when they are cooked. So if you want to make a tomato sauce (where the tomatoes gradually break down, like a Pomodoro recipe), use whole canned tomatoes without the Calcium Chloride. Muir doesn't use it nor do imported San Marzano plum tomatoes.
Bon Appetit had good recipe for Basil Pomodoro but they only let you view it once without subscription. So I can't show it here.
Oh yeah, I didn't know why at first, but I knew that canned diced tomatoes were always hard and no amount of cooking would break them down.

I got so ticked when my little cousin asked for my pappa al pomodoro soup recipe and posted it all over social media saying it my cousin's recipe tagging me in the posts. She made it with canned diced tomatoes and everyone commented how it looked nasty. I told her specifically, I even put it in the typed recipe - DO NOT USE any kind of tomato except whole San Marzano/plum tomatoes that you crush by hand. I said DO NOT USE diced tomatoes. Her soup was yellow/green from all the hard un-ripe tomatoes. I replied to every comment that she didn't use the right tomatoes and posted a picture of it made correctly. She is now blocked from not only my social media but my life for so many reasons, this being the least of them but still this one really hit me wrong because it did look pretty nasty - bread and green/yellow bits of tomato. Oh and she used white loaf bread.