Soap Ash... ugh?
Soap Ash is a white, chalky looking film that sometimes appears on soap and is caused when unsaponified sodium hydroxide reacts with naturally occurring carbon dioxide in the air. The soap is still safe to use, it just does not look as nice. While avoiding it in the first place is best, such as insulating / wrapping the soap and keeping it warm longer and delaying the cooling time so the soap can saponify, it can happen. Some cold press makers spray isopropyl alcohol (rubbing alcohol) to make a barrier to the air; steam off the ash when the bar is firm; or cut it off to maintain a desired nice look. I either leave it and use the soap for myself, cut it off or leave it if minor. So next time you see a soap with ash on it, don't fret, it is still okay to use and is not visible once wet.