While a rock might not seem like the most pristine surface, this one is. This piece of marble will make you shine. Hack off a piece when you need one, and do as your grandma did and clean yourself up without plastic bottles and unknown chemical components.
500 g olive oil
64g sodium hydroxide (NaOH)
178g water (H2O)
First, mix the water and sodium hydroxide together. This creates lye.
Measure the correct amounts of water and sodium hydroxide. Use a heat-resistant pitcher when measuring the water, and a mason jar with the sodium hydroxide.
Add the sodium hydroxide in a slow and steady stream to the water and avoid splashes. Do not attempt this the other way around (adding water to sodium hydroxide) as this can invoke a volcano-like reaction.
Store the sodium hydroxide away safely, making sure not to spill on furniture or clothes.
Gently stir with a wooden spoon until the sodium hydroxide is completely dissolved. Due to the chemicals reacting the mixture will start to get hot – about 200 degrees Celsius – and may even start boiling, so be careful.
After stirring, store the mixture away in a safe place to cool.
When the mixture has cooled to about 50 degrees Celsius, it is ready to use.
Once the lye has been made and is cooling down, start making the soap.
Measure the olive oil into a cooking pot. Slowly heat the oil, until it reaches about 50 degrees Celsius. Take your time, as oil heats faster than lye cools down.
When the oil and lye reach the same temperature, slowly pour the lye into the oil while stirring. The mixture will become cloudy when combined.
Use the immersion blender to keep the soap mixture moving. This can also be done by hand, which would require about an hour of on-and-off stirring. Using a blender speeds up the soaping process. The mixture will gradually thicken after 15 minutes of blending (or an hour when using a spoon). You can check this by drawing a line with a wooden spoon through the mixture. If the spoon leaves a trace for a while, the mixture is ready to pour.
At this point, add fragrance oils and/or colouring. Mix well to combine.
Pour the soap into the mould and let it rest for 24 to 36 hours, until it becomes hard. When the soap is hard enough, cut and slice as you please. Let the pieces of soap sit for another two to four weeks, so the chemicals can fully react and the water can evaporate.
Wash your hands and feel clean!