Olive oil soap (Castile soap)!

Pure Olive Oil Soap (Castile Soap)

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A 100% olive oil soap recipe is also called a “Castile” soap recipe in English-speaking countries. But, not all soaps labeled “Castile” are truly 100% Olive Oil. The following recipe is for 100% pure olive oil soap.

Olive Oil Soap Recipe (Castile Soap) COLD PROCESS

  • 700 ml olive oil
  • 90 gr  lye
  • 260 ml water

The soap is going to look more like this unless you add some other materials like herbs.



  1. Picture one: You make your mold ready.
  2. Picture two: You mix lye in the ice cold water (Lye in the water not the other way around, you can cause an explosion!)
  3. Picture three: stir the solution in the oils. Both the lye solution and the oil solution has to be the same temperature (43 C) in order to have a successful combination.
  4. Picture four:  Use a stick blender to mix. Keep your eyes on the batter because trace can be reaches quickly. Do not mix bubbles into the batter, so keep the stick-blender deep down.
  5. Picture five: Pour your soap into your mold whatever that is! Cover with a cloth and keep it somewhere at a nice warm temperature of 20-25 C and wait for 2 days.
  6. Picture six: With your googles and gloves on, unmold the soap and cut it in pieces. Store your cut soap in a cool dry place for at least 2 weeks (important so the soap in curing to a neutral pH 7). I leave it for 4 weeks. If you use the soap before that it might still be too alkaline and burn you!After that your soap is ready to decorate with a seal, or to grate-pour and cast or “handmilling” process soap. That is, you use the  soap you already made to make new soaps with colors and scents!


  • Follow safe soapmaking procedures
  • This site has excellent instructions on how to make soap
  • I added no essential oils to this olive oil soap recipe, but a general guide for most essential oils is to add  150 ml 0.5 kg  of soaping oils.
  • I bring mine to a fairly thick trace so I can make some swirls reminiscent of the hot process ones
  • Let your soap cure for about 6 weeks for the hardest, mildest bars.

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