Method
Step One: Gear up for safety: wear googles and gloves and keep them on at all times. Weight the sodium hydroxide in a glass or ceramic bowl. In a separate heat safe stainless steel or Pyrex glass bowl, weigh the fridge-cold water.
Step Two: Wear your respirator. Slowly add the sodium hydroxide into the water. Stir well with a stainless-steel tablespoon until fully dissolved.
Step Three: Let the lye solution cool down until it reaches 43°C (120°F). In the meantime, weigh the oils in a heat safe glass or ceramic bowl. Place this in the microwave or bain-maire to melt the coconut oil and the shea butter and heat up the olive oil. The oils should also be at around 43°C (120°F).
Step Four: Measure the temperature of the lye solution and the melted oils. If the temperature is correct, slowly add the lye solution into the oil and mix with a spatula or a tablespoon until they are all combined.
Step Five: It’s time to stick blend. Do so until the soap is still very runny but you can clearly see that the batter has turned out to be fully mixed in and has an opaque colour.
Step Six: At this point, add the essential oils and mix them in with a spatula or tablespoon. Stick blend again until you reach a slightly thicker trace that looks more like a light custard.
Step Seven: Pour the batter into the mould, tap to remove any air bubbles and cover the mould with a piece of cardboard (or place it inside a shoe box) and cover it with a towel or blanker to keep it warm.
Step Eight: Let the soap harden for 24 hours, then unmould and leave to cure for four to six weeks before using it.
If you are interested in learning more about making your own soaps and shampoo bars, visit the Bottega Zero Waste online school.