How Does Lye Turn Fats into Soap During Saponification?

💡 The Answer

• Lye (sodium hydroxide) attacks ester bonds in triglycerides, breaking them into fatty acid salts and glycerol.
• The fatty acid salts are the soap molecules, having a hydrophilic head and a hydrophobic tail.
• This reaction is exothermic and requires careful temperature control for proper soap formation.
• The process yields about one part soap to one part glycerol, which can be separated or left in for moisturizing.