Time: 1 hr
Yields: 500 g soap
Castile soaps are named after the Castile region in Spain, where the olive oil based soap originated. Historically, the soaps were made from olive and laurel oils, but nowadays, castile stands for soaps made with 100% olive oil. However, pure olive oil soaps have a rather poor and thin lather due to the fatty acids combination of olive oil. To increase the lathering qualities, I’ve added a small amount of castor oil to the soap recipe, which gives the soap a nice creamy lather.
If you have never made cold-process soap before, I strongly suggest you check out the basic cold process soap tutorial first.
Before starting, please read the safety and precautions post, especially since this tutorial requires the handling of caustic soda!
ONE: First, prepare your lye. Weigh out the caustic soda in a small container. Measure the water in a small pyrex or other heat proof glass jug. Then carefully add the caustic soda to the water and gently stir until all the caustic soda has dissolved. Stir one teaspoon of sodium lactate to make the soap harder. Set aside to cool.
TWO: Weigh out the olive oil into a large jug or pot. Add the castor oil. Pure olive oil soaps usually have a poor lather, and castor oil will help increase the lathering properties.
Wait until the lye has cooled down to room temperature, or around 25C (77F).
THREE: Make sure you are still in protective gear (goggles and gloves), carefully pour the lye to the oils, avoiding any splashes. Give it a quick pulse with the stick blender.
FOUR: Add the lavender essential oil and give it a quick stir with the stick blender. Then keep alternatively pulsing (5-10 seconds) and stirring with the stick blender until you reach trace.
FIVE: Pour the soap into the mold, and then gently tap the mold on the bench a few times to get rid of any air bubbles in the soap. Scatter dried lavender flowers on the surface and then leave the soap to cure overnight or until it is hard enough to remove from the mold. Olive oil soaps tend to be a bit softer initially and take longer to harden.
SIX: Once the soap has hardened and doesn’t stick to the sides anymore, you can remove the soap from the mold. Let the soap cure for another couple of days before cutting into bars. The bars will then need at least 6-8 weeks to cure before they are ready to use.
Lavender Castile Soap
- 375 g olive oil
- 25 g castor oil
- 50 g caustic soda
- 100 ml water
- 1 teaspoon sodium lactate
- 20 ml lavender essential oil
- dried lavender flowers
- Prepare your lye: carefully add the caustic soda to the water and stir gently until all the caustic soda has dissolved. Add one teaspoon of sodium lactate. Set aside to cool.
- Weigh out the oils in a large jug or pot.
- Once the lye has cooled down to room temperature, carefully add it to the oils and stick blend briefly.
- Add the lavender essential oil, and keep alternatively pulsing and stirring with the stick blender until trace.
- Pour the soap into the mold, and gently tap the mold on the bench a few times to get rid of any air bubbles in the soap. Scatter lavender flowers on the surface and then leave to cure overnight or until hard enough to remove from the mold.
- Once the soap is hard enough, remove the soap from the mold and let it cure for another couple of days before cutting into bars. The bars will need another 6-8 weeks to cure before they are ready.