Hey sparrowgrass, just a tip. The original source of this idea suggested it would take 20 to 40 minutes for the top layer of your undisturbed tomatoes to soften. Mine took an hour just due to the large vat of tomatoes i had.
I also wanted to give credit for this idea. I found it in my all time favorite magazine ever, Countryside and Small Stock Journal (small stock as in animal, not Wall Street!). It is a reader written homesteaders magazine, not unlike this forum, lots of ideas from different perspectives.
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. Margaret Mead