What is French milling in regards to soap? What’s the difference 'tween French milled soap and other soap and why is it to be desired? I washed with some such soap at a hotel stay this week and I could discern no difference.
French milling is pretty much the standard manufacturing method for bar soap. Pure soap is mixed with color, fragrance, or whatever, and various processing steps are used to reduce the particle size so that the mass becomes smooth and malleable. Then it’s formed into a log and cut into bars, which are then pressed into their final shape. One of the steps is a roller mill – that’s the “French milling” part.
Soap can also just be poured into molds; milled soap is drier, harder, denser, and less-likely-to-melt-in-the-shower than poured soap. I don’t really think there’s any inherent difference in quality; one’s own experience is determined by formulation, skin type, and the use of other products like lotions.