I missed the last post in the other thread, had a nice long reply, and it was locked, and my post is lost in outer space!
I hope that I can remember what I said! Grrr! Brain not so great on thinking it over again...
I often can excess goat milk. I use a pressure canner and a meat recipe for timing. It ends up dark in color, kind of like canned evaporated milk at the store. It works fine for cooking, but not for drinking... it tastes well, cooked kind of like evaporated milk does (to me).
I canned cream of chicken, cream of broccoli, and cream of celery soups... I experimented because my recipe said... do not thicken...
well, I had to be a chemist... I did in fact use corn starch in one, flour to thicken the other one, and the other 4 I followed the recipe and didn't add milk or thickening agent.
The corn starch did absolutely nothing. I think that corn starch has one time of thickening and doesn't repeat if you go above a certain temperature???
The flour separated out and sat on the bottom, where it made a hard, impervious layer. At point of use, it took me a lot more time to mix that flour back into the soup, than it did to just use the others and add the flour and milk when I heated it for eating. And the ones that I added the milk later, were prettier in appearance than the long processed ones containing the milk.
In my opinion, the experts were right... don't add the milk and flour until you are heating it to eat it.
The milk increases the processing time, and the flour separates.
Not expert by far, just my experience.
I hope this is not now locked.