“I’ve heard you can buy canned sauce and just transfer it to jars and reprocess it.”
For true SHTF long term storage spread it out and dry it then bag or jar it. It will also reduce the bulk by 90% or better. just re-hydrate when needed. :)
I tried tomato powder and it just solidified in the container. (I’ve been playing around with emergency storage since 2009, when the antichrist first took power.) So I know to stay away from dehydrated food and choose freeze-dried instead, and definitely avoid dehydrated tomato powder. Not only did I lose the powder, but I had to toss the jars also. It was like concrete.