How did Greeks make Greek fire? Did they put oil in the bottle because it could burn on water due to its ability of floating on it?
This is an interesting topic, although how do we put the fire out? So that's 2 questions
We don't know how it was made because the formula for it has been lost. It was probably not even the same thing in every case, but instead a generic name for incendiary weapons. The real power of Greek Fire seems to be that the Byzantines delivered it in tube, like a flamethrower, rather than catapults.