This post will touch on the basics, and help show why I have a fascination with soap.
What Is Soap?
Soap is a combination of vegetable oil or animal fat with an alkali.
Vegetable oils can be from olives, palm, coconut etc
Animal Fat is also known as fatty acid and is TALLOW.
Straight away this is great news as it means that Vegans, Vegetarians and Meat lovers can each choose a soap that fits in with their lifestyle choice if need be.
The adding of the alkali is critical. Many people question the use of Lye in soap but the reality is without it you cannot call your product soap. Lye when combined with the oils/ fats produce either sodium palmate (when mixed with palm oil) or sodium tallowate (when mixed with animal fat).
How Does Soap Work?
Soap is a surfactant. This means it is a surface active agent. It works by reducing the surface tension between two items.
Contrary to popular belief dirt does not require soap to wash it off. Simple water can do that by its self. However dirt generally contains other substances oil / grease etc and this needs a surfactant to enable it to be washed off of the skin. Oil and water do not mix, yet soap has molecules which attract others e.g. oil and water. A lather is created, it attracts the oil / water and does not let go of them until they are washed away. This is the same for diseases and germs which is why we should always wash our hands and encourage children to also do so. Hospital staff are so aware of the need to get a good lather onto hands that they have designed specific ways in which hospital staff must wash their hands in order to best remove germs.
Soaps’ Amazing History
No one really knows how soap was invented, but it is fun to imagine cavemen sitting around a fire, wondering what the bubbles were that formed in the camp fire ash each time fat dripped down from the animal that was rotating on the spit above! The first recorded writing concerning soap is actually Babylonian. Inscribed up on a clay tablet were the ingredients for an early ‘soap’ involving cassia oil, water and alkali. This dates the known history of soap to circa 2,200 BC. Then in 1,500 BC inscriptions from Egypt mention the combination of water, alkali and tallow.
Like any good story there are many claims to where the name ‘soap’ derived. The most plausible is from Rome. Mount Sapo. Here at Mount Sapo animals were sacrificed, their fat was washed down the alter into the ash causing a chemical reaction ‘soap’ and the name as we say today ‘stuck’.
Making the Modern Soap
There are 5 techniques that are used to produce today’s soap. None of which are quite as crude as previously mentioned yet they all involve at some point the same basis.
Take your hard and soft oils and melt in a saucepan or crockpot. Making sure you are wearing mask, eye protection and gloves weigh out your lye. In another glass jug weigh out water. Slowly pour the lye into the water and stir. Never pour water into lye unless you wish to replicate a volcano!!!! Stir until dissolved. Pour this solution into the melted oils. Get a blender or have a strong arm and mix until ‘trace’ is formed. This is where the mixture starts to harden. At what I can only say is something that resembles mash potato goo switch off the heat. Remove the mixture and place into another dish unless you do not mind dying your crockpot / saucepan. Take some and place into a small jar and mix into this colours / fragrances. Then transfer it all back to the main body of mixture and stir – but do not over stir. Pour into mould.
Very similar to HP. Except that once the trace appears do not continue to cook / heat any more. Remove from all heat sources, add your extras then pour into mould. Insulate and leave for 24hrs. During this point further chemical reactions occur. Once cool, cut into desired shape and let cure for approx 6 weeks. It is during these weeks that the saponification process completes.
Melt & Pour
Saponification has already occurred with vegetable glycerine as the base. The base is cut up and then remelted on a stove or in a microwave. Once slightly cooled all extras can be added and poured into mould. M & P is used for delicate artisan moulds, multi layering, swirls, embedding etc.
Salt is added and then the crude soap is put through milled rollers. Glycerine and water is removed resulting in a very dry soap. Popular in France.
The soap you see in many shops and supermarkets is industrial. A need for this process came from the war. Animal fat was in demand for the war effort and so another way was needed. A detergent invented by Germans came about. This chemical detergent is used throughout the household cleaning industry and cosmetic and beauty industry. They have a reputation as being very powerful and can be harsh on skin requiring further chemicals to be added to reduce this effect. Sodium Lauryl Sulphate and Sodium Laureth Sulphate: harsh chemical degreasing foaming agents (known to strip car engines of oil).