The Marseille saponification is a traditional and discontinuous soapmaking process that includes cooking the paste in a cauldron. Characterized by five main stages (pasting, releasing, cooking, washing, liquidation), it takes place according to a cycle of 8 to 10 days during which the paste is worked in the boil during the day and left to rest overnight. All these steps are supervised by a soap master, like Michel Bianconi at the Fer à Cheval soap factory, or his apprentice.