Mechanic Cold Process Soap Tutorial
Recipe type: Cold Process
Serves: 3 pounds of soap
This soap is made with walnut shells and pumice for an extra scrubby feel.
  • 12 Bar Round Silicone Mold
  • 9.6 oz. Coconut Oil
  • 9.6 oz. Olive Oil
  • 9.6 oz. Palm Oil
  • 1.6 oz. Castor Oil
  • 1.6 oz. Cocoa Butter
  • 9.4 oz. Distilled Water
  • 4.6 oz. Sodium Hydroxide Lye
  • 1.7 oz. Orange 10X Essential Oil
  • 5 Tbs. Pumice
  • 8 Tbs. Walnut Shells
SAFETY FIRST: Suit up for safe handling practices! That means goggles, gloves and long sleeves. Make sure kids, pets, and other distractions and tripping hazards are out of the house or don’t have access to your soaping space. Always soap in a well-ventilated area.
FRAGRANCE PREP: Measure 1.7 ounces of orange 10X essential oil into a glass, fragrance oil safe container.
  1. Slowly and carefully add the lye to the water and gently stir until the lye has fully dissolved and the liquid is clear. Set aside to cool.
  2. Melt and combine the coconut oil, castor oil, cocoa butter, palm oil, and olive oil (remember to fully melt then mix your entire container of palm oil before portioning). Once the lye water and the oils have cooled to 130 degrees or below (and are ideally within 10 degrees of each other). Place 5 tablespoons of pumice in a small container, and add 5 tablespoons of the soaping oils into the container and mix together. Doing so helps get rid of clumps, without adding too much extra oil into the soap. Set aside.
  3. Add the lye water to the oils and stick blend until thin trace. If you’d like a harder bar of soap that releases faster from the mold, you can add sodium lactate to the cooled lye water. Use 1 teaspoon of sodium lactate per pound of oils in the recipe. For this recipe, you’d add about 2 teaspoon sodium lactate.
  4. Once you’ve reached a thin trace, add the orange 10X essential oil and use the stick blender to mix in. Alternate using short bursts and stirring with the blender to avoid over stick blending.
  5. Add the pumice mixture into the soap, and use the stick blender to mix in. This will cause the mixture to thicken.
  6. Add 8 tablespoons of walnut shells and use a whisk to fully mix in.
  7. If your batter is thin enough to pour, fill each cavity evenly. I found mine was quite thick, so I used a spoon to fill each cavity. Tap the mold firmly on the counter to help eliminate the air bubbles. Spritz the soap with 99% isopropyl alcohol to help eliminate soda ash.
  8. Allow the soap to stay in the mold for about 2-3 days. Unmold, and allow to cure for 4-6 weeks. I used the Soap Shaver to smooth out the textured top of the soaps, but this is optional.
Recipe by Soap Queen at