Why doesn’t this exist?
Take dried beans, roast 'em, grind 'em, and brew some bean juice?
I have no idea if it would taste good or not, but we don’t know if we don’t try.
Edit: I need to see what dried beans I have and maybe go shopping. I will give this a try with a couple different types of beans and report back if I fart or not.
That’s kind of what aquafaba is but you don’t need to grind or roast them, because most times you want aquafaba to be quite thick. I don’t know how often it’s used elsewhere but I know it can replace egg whites in coctails that call for egg whites.
Apparently you can even make meringue with it. Haven’t tried that but I often make mayonnaise with aquafaba.