thought I could substitute canned diced tomatoes for whole san marzanos, or pureed/crushed tomatoes to get the same result just by cooking these down a bit longer, softening them up and hoping to get the same result for a marinara sauce I have to serve on Thanksgiving day.
But after 45 minutes the diced tomatoes still look the same as they did when they were inside the can.
Why is this happening? Any type of heat applied to most liquid contained food should break down. What is wrong with these freak resilient diced tomatoes?