Nah it would be pretty easy to discover soap accidentally. People have been using ash to scour metal for ages. Someone scours a plate or bowl with some leftover

Nah it would be pretty easy to discover soap accidentally. People have been using ash to scour metal for ages. Someone scours a plate or bowl with some leftover fat or oil or grease in it and it cleans really well, because it makes a kind of soap. It only takes one person to notice this fact, and the idea catches on.