Serves 1
Directions
- 1Weigh out 1000 grams of avocado oil into a glass measuring cup.
- 2Pour the avocado oil into an Instant Pot set to the slow cooker setting on medium.
- 3Place another glass measuring cup on the digital scale and zero it out.
- 4Weigh out 210 grams of potassium hydroxide into the glass measuring cup.
- 5Weigh out 250 grams of distilled water into a separate glass measuring cup.
- 6Weigh out 250 grams of glycerin into the same measuring cup as the distilled water and stir.
- 7Weigh out 30 grams of peppermint essential oil into a small beaker.
- 8Add the peppermint essential oil to the oil in the Instant Pot.
- 9Carefully add the potassium hydroxide to the water and glycerin mixture, stirring with a glass stirring rod until dissolved. Do not add water to potassium hydroxide.
- 10Use an infrared thermometer to check the temperature of the potassium hydroxide solution. It should be below 175°F (79°C).
- 11Check the temperature of the oil in the Instant Pot. It should be between 160-175°F (71-79°C).
- 12Gradually pour the potassium hydroxide solution into the oil in the Instant Pot while continuously mixing with an immersion blender.
- 13Continue blending until the mixture reaches a thick, trace-like consistency (about 7 minutes), resembling a thick applesauce.
- 14Cover the Instant Pot and cook the soap paste on the slow cooker setting, stirring every half hour, until it becomes translucent and gel-like. This took about 4 hours.
- 15To test for readiness, add some warm distilled water to a small jar.
- 16Add a small amount of the soap paste to the jar with water, close the lid, and shake well.
- 17If the solution in the jar is clear, the soap paste is ready.
- 18Add water to the Instant Pot with the soap paste to dilute it, filling it up.
- 19Stir the diluted soap, cover the Instant Pot, and leave it on low overnight to dissolve completely.
- 20The next morning, check the pH of the dissolved soap using a universal indicator paper; it should be around 9.
- 21Pour the liquid castile soap from the Instant Pot into glass jugs for storage.
- 22For hand soap, fill a hand soap dispenser about a quarter full with the concentrated liquid castile soap.
- 23Top off the hand soap dispenser with tap water and shake to mix.
Ingredients
- 1000 grams Avocado Oil
- 210 grams Potassium Hydroxide 90%
- 250 grams Distilled Water
- 250 grams Glycerin
- 30 grams Peppermint Essential Oil
- Water to reconstitute
Equipment
Digital kitchen scaleGlass measuring cupInstant Pot with slow cooker settingImmersion blenderSilicone spatulaInfrared thermometerSmall glass jar with lidPH test stripsGlass jugsFunnelHand soap dispenser
Tips
- When mixing water with potassium hydroxide, always add the potassium hydroxide to the water, not the other way around.
- Always wear gloves and eye protection when working with potassium hydroxide, as it can burn your skin.
- Ensure the potassium hydroxide solution and the oil are both between 160-175°F (71-79°C) before mixing them.
- An immersion blender helps to quickly emulsify the mixture; otherwise, you can mix by hand, which will take longer.
- To test if the soap paste is ready, dissolve a small amount in warm distilled water; if the solution is clear, it's done.
- The final pH of the dissolved soap should be around 9.
- The concentrated soap paste can be stored for at least a couple of years in a glass container.
- When diluting for use, tap water can be used, but it might make the soap cloudy.