I'm currently working it out. Different ways of cooking and fermenting. It just takes a lot of time To make them edible. Really old beans don't like to soften.
My trick is I tap into the LDS community. I am always telling my LDS friends. If you know anyone getting rid of old food storage I'll take it. I literally have hundreds of number 10 tin cans of wheat. Ferment it and boom! chickens love it better then feed. Old canned potatoes from the 60s soak...