How to Use the Handmade Soap Ingredient Calculator
Accurate lye calculation is the most critical step in cold-process soap making. Too much lye produces a caustic bar; too little means it won't saponify fully. Select your oil type, enter the total oil weight, and choose your desired superfat percentage. The calculator provides exact NaOH and water amounts. Always verify results with a dedicated soap lye calculator before making a new recipe.
SAP Values by Oil Type
| Oil | SAP Value (NaOH) | Properties |
|---|---|---|
| Olive oil | 0.134 | Gentle, moisturizing |
| Coconut oil | 0.190 | Hard bar, rich lather |
| Palm oil | 0.141 | Hard bar, stable lather |
| Castor oil | 0.128 | Boosts lather, moisturizing |
Frequently Asked Questions
Saponification completes in 24โ48 hours, but curing (drying out excess water) takes 4โ6 weeks. Cured soap is harder, milder, and longer-lasting. The finished bar weighs roughly 25% less after curing.
Calculate each oil separately: oil weight ร SAP ร (1 โ SF) for each. Add all lye amounts together. The water is always based on total oil weight ร 38%.