Reading those processes, got to wonder how someone first ran across these foods. Seems like an odd direction to go when looking for a new flavor. With that said I have never really delved into food creation so maybe I am completely wrong.
Marmite was invented fairly recently (late 19th/early 20th century), apparently by a german scientist who was studying food chemistry and nutrition. (In case you missed the joke, the liquid the parent suggests you can discard is beer).
Miso I know less about but my wild guess would be it's some sort of by product of trying to preserve food.
