The secret of soap fabrication lies with know-how passed down from generation to generation by master soapmakers. If saponification is simple in theory (oil, soda, and saltwater), it requires, above all, significant knowledge that the master soapmakers acquire after four years of training. Michel Bianconi, master soapmaker at the Fer à Cheval soap factory, has thus already been training Stéphane, one of his former colleagues' son, for several years.