Soap is a chemical reaction that occurs as a result of mixing an animal or vegetable fat with a base Each fat has a combination of triglycerides. Triglycerides are compounds made up of 1 molecule of glycerol and 3 fatty acid molecules. The alkali in soap-making is sodium hydroxide, also known as lye.
The lye is mixed with water to create a basic solution. This solution is then mixed into your fats. As they are combined and begin to react, the glycerol molecule is separated from the fatty acids. The fatty acids then react with hydroxide ions in the lye solution. The two resulting products are glycerin, which is wonderfully moisturizing for the skin, and soap. No lye remains as it has all reacted to create a completely new substance. “I’m blinded by science”
There are countless combinations of oils you can come up with for a soap recipe. Each fat or oil has its own impact on your finished product. You can use all of one type of oil or a mixture of several different oils . A pure olive oil soap, called castile soap , makes a very gentle soap. Tallow soap has an increased cleansing ability. With a blend of oils it is much easier to achieve the qualities you are desiring in a soap.
Some of the most popular soaping oils are:
- coconut oil
- olive oil
- castor oil
- cocoa butter
- mango butter
- sunflower oil
- sweet almond oil
- jojoba oil
A good place to start is by using olive oil, coconut oil, and castor oil. This combination will give you a mild soap with a good lather.
You can adjust the scent up to 3% of all the oils and water combined. Anything over 3% would be very strong. I recommend starting at 2%.
Air circulation is a must. Be sure that your bars are not touching and there is air flow between layers. If soap is touching it will form moisture between the bars and they may not cure as fast as they could.
How to make cold-pressed soap
- coconut oil
- palm oil (ideally sustainably sourced)
- olive oil
- caustic soda
- Essential oil
- Weigh out the coconut oil and palm oil into a saucepan. Melt them together with light heat.
- While the oils are melting, make the lye: pour the caustic soda into a pan containing water. Wear PPE when working with lye. Ventilate the area.
- When both pans have cooled to around 110F, combine their contents. emulsify until it’s thick enough to leave drizzle on the surface.
- Add essential oils and any other ingredients you like.
- Pour into a mold lined with grease-proof paper.
- Leave to cool. After cooling, cut it into blocks, wrap and leave for a month to cure.