10 pts. to first good answer about glycerin soap?

Question

Okay, has anyone ever noticed that if you leave a bar of glycerin soap in a cabinet or wherever too long, it "sweats" out white chunky stuff that sits on the surface of the bar?

What is that stuff? Why does it get "sweated" out?

Answer 1

The white chunky stuff is dried humid air mixed with soap. It is created by the fact that the glycerine soaps contain a lot of humectants which attract moisture from the air (your bathroom is a very humid place) and then the moisture actually sits on the top of the soap. So it isn't the soap sweating it is the moisture from the air sitting on the soap and drying.