Originally Posted by spunkmaster

I was an Italian Cook 25 years ago in a real Italian restaurant in New York and here's your answer:

If it's made from fresh crushed tomatos then it needs to cook for 8 -9 hours on a low simmer (with a lid) or crock pot.

If it's made from paste then it's done after 1-2 hours because the paste is already cooked down.

I use 50% diced tomatos and 50% paste and cook it for 4-5 hours the
night before and let it sit all day the next day then heat it up an hour before serving