1st step: Mashing, The oils or fatty acids and lye are successively added to the cauldron (most often made of metal presently) under moderate heat, then brought to a boil, and the mass transforms and emulsifies,
2nd step: Salting-out, Since soap does not dissolve in salty water, this operation consists in adding sea salt so as to wash out the salty glycerine effluents. In this step the soap loses part of its water content.
3rd step: Boiling, This operation characterizes the saponification and leads to the complete transformation of the vegetable fats into soap.
4th step: Washing, This is a refining step which refines the soap paste by washing it to remove the glycerol, any impurities, and the fatty acids which did not turn into soap
5th step: Liquidation, In this operation, water is added to cause the crystalline structure of the soap to transition to the smooth phase.
Marseille soaps are required to have a minimum of 72% vegetable oil. Authentic Marseilles soaps are stamped “Savon de Marseilles” and “72%” on the soap.