Lye Is Mandatory and Dangerous Without Respect Cold process soap cannot be made without sodium hydroxide (lye). Every bar of soap in the world was made with an alkali. The lye fully reacts with the oils during saponification and is not present in the finished bar. However, handling lye before it reacts requires goggles, gloves, long sleeves, and good ventilation. Keep a bowl of white vinegar nearby to neutralize any lye spills on skin. Never use aluminum tools or containers: lye reacts with alum
How Saponification Works
Saponification is the chemical reaction between lye (sodium hydroxide) and fats that produces soap and glycerin. Every oil has a saponification value (SAP value) that tells you exactly how many grams of lye are needed to fully convert one gram of that oil. Soap calculators (like Soapcalc.net) do this math automatically. Always use a 5 percent superfat, meaning 5 percent of your oils remain unsaponified in the final bar, leaving a slight conditioning buffer. Never eyeball lye amounts. A kitchen scale accurate to 1 gram is non-negotiable.
5Percent
4to 6 Weeks
Run Your Recipe Through a Soap Calculator
Before weighing anything, enter your oil blend at Soapcalc.net or SoapMaker3.
Run Your Recipe Through a Soap Calculator
Before weighing anything, enter your oil blend at Soapcalc.net or SoapMaker3. A simple beginner recipe: 40 percent olive oil, 30 percent coconut oil, 30 percent palm oil (or lard). The calculator outputs the exact lye and water amounts for your batch
Mix the Lye Solution
Weigh distilled water into a heat-safe container (HDPE plastic or stainless).
Mix the Lye Solution
Weigh distilled water into a heat-safe container (HDPE plastic or stainless). Weigh lye separately. Always add lye to water, never water to lye: adding water to lye creates a violent reaction and can spatter. Stir slowly. The solution will reach 180 to
Combine Oils and Reach Trace
Melt hard oils (coconut, palm) and combine with liquid oils (olive, castor).
Combine Oils and Reach Trace
Melt hard oils (coconut, palm) and combine with liquid oils (olive, castor). Bring to roughly the same temperature as your cooled lye solution (90 to 110 F). Slowly pour lye solution into the oils while stick-blending in short bursts. Trace is reached
Unmold, Cut, and Cure
Insulate the mold with towels for 24 to 48 hours to allow saponification to
Unmold, Cut, and Cure
Insulate the mold with towels for 24 to 48 hours to allow saponification to complete. Unmold once firm. If the surface is soft or sticky after 48 hours, leave it another day. Cut into bars with a soap cutter or wire. Place bars on a rack with space
Before You Start Any Batch
Goggles and gloves on before lye touches any surface
Recipe confirmed through soap calculator (not estimated)
All tools and containers confirmed non-aluminum
Distilled water weighed (not tap water, which can cause issues)
Lye weighed on a scale accurate to 1 gram
Ventilation open: window or fan running