The Marseille manufacturing process
Authentic Marseille soap is made in a cauldron, using a specific saponification process, called the “Marseille process”, comprising 5 stages:
1. Pasting, or saponification chemical reaction.
The mixture of lye and vegetable fats is heated and brought to a boil in the cauldron. It is gradually transformed into soap.
2. Release
As soap is insoluble in salt water, this operation consists of adding a very dense salty lye in order to drag the excess soda to the bottom of the cauldron. The soda “releases” that is to say it goes down to the bottom of the tank, the soap remaining above.
3. Cooking
This allows the complete transformation of fatty substances into soap by adding concentrated lye. It is an essential operation which explains “the proverbial longevity” of Marseille soap.
4. Washing
The soap paste is refined through washing, removing glycerol, impurities and unsaponified fatty acids.
A final wash with clean water brings the soap to its final state. Then floats the smooth and pure soap which makes the reputation of the Marseille process.
These different operations take approximately one week to ten days.
