I discovered this quite by accident last year. I was in the middle of canning tomatoes when my husband needed me.
I put my tomato sauce in the fridge and later discovered to my delight that the thick stuff settles!
Another reader of mine shared that she does this too. In fact it is more common that I realized. I just didn't know about it!
Place your tomato sauce from the food mill into your large stock pot. Let it cool on the counter.
When it is somewhat cool, place in the fridge overnight.
The depth of this clear layer will depend on the type of tomato and how juicy it is. These pictures are from a Roma tomato which is meatier than many other types.
My son calls this clear liquid tomato broth. My reader called it tomato whey.
What ever you call it, if you skim or siphon it off, the thicker tomato sauce is at the bottom. This step will shorten your cook down time.
You will probably still need to cook down for a couple of hours but not nearly as long as if you were not able to skim off the liquid first.
You may want to share this. Don't waste that precious tomato juice by cooking down the tomatoes to sauce or paste.
Squeeze the tomatoes by hand or as I do it, put them in my blender or Ninja to crush them. I then drain them really well through my strainer, saving the juice and canning the juice separately. I usually get 3 or more quarts juice to 1 quart sauce...adding 2 tbls lemon juice works great per qt. and heat the juice to boiling before canning.
It's delicious and so good for you. If you like tomato soup, add a bit of salt and finely ground black pepper to the juice and boil it down a bit. I just can it with the same headspace and time as tomatoes in waterbath.
I have attempted to share safe preserving methods. However, I make no promises. You alone are responsible for your health. Be aware of current safety recommendations.
See my Full Disclaimer here.