How do you make soap?
This is a question I’m frequently asked – so here's a little bit of the science behind the process.
Cold process soap, the type I make, is a traditional method, made from scratch using an alkali, water, oils, and butters. We know oils and water don’t mix, so an alkali must be used to cause the chemical process.
The combination of these basic ingredients causes a chemical process called saponification. This results in the creation of beautiful hard bars of nourishing soap.
Although the technique is called cold process it does in fact require some heat to melt the fats (oils & butters).
The lye solution will also be hot, as it heats itself. This is a natural reaction when mixing sodium hydroxide and water.
The soap is made by combining the lye solution (sodium hydroxide & water) with the oils and butters. When mixed under the correct conditions they neutralise to form soap.
This is known as saponification.
Saponification is the chemical reaction when an ester (oil & butter) is mixed with an alkali (lye). The alkali breaks the ester bond and releases fatty acids and glycerol, this results in the end product of soap being rich in glycerol, the naturally produced glycerin in our bars.
It is impossible to make soap without the use of the lye solution but rest assured if made correctly there is NO sodium hydroxide (lye) left in the final product after it has been through the saponification process.
The post saponification period is now the curing process (the waiting game). This is when the soap is left to dry out. During this process any traces of lye will transform into soap. The water content evaporates which in turn makes for a hard bar of soap. This stage takes approximately 4-6 weeks resulting in a natural bar of soap. The longer it's cured the harder the bar – the longer it will last.