In soapmaking, lye (sodium hydroxide) is mixed with water and fatty oils to create a saponification process, whereby oil is turned to soap from heat and the reaction with the lye. SOAP CLUB CURIOUS? JOIN SOAP CLUB Share this:Click to share on Facebook (Opens in new window)Click to share on Pinterest (Opens in new window)Click to share on Telegram (Opens in new window)MoreClick to share on Reddit (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on WhatsApp (Opens in new window)