The percentage of sodium Hydroxide in a formula is carefully calculated according to the degree of saponification desired. When enough sodium hydroxide is used to supply all of the fatty acids with sodium hydroxide mates, the soap is considered fully saponified. No discount is taken from the percentage of sodium hydroxide required for complete saponification. The full saponification does not contain excess oils. By using less sodium hydroxide or discounted amount, soap becomes superfat. Superfatted soap would leave oils unsaponified roam free in the formulation. The left over oils then will become moisturiser that moisturise your skin after rinsed off.
23
Jan