The History of Soap
It began long before the invention of writing; initially, knowledge of it was passed down orally. As early as around 2000 BC, the Sumerians described on their clay tablets the process of making a soap paste from clay, vegetable oil and ash.
Later, the Egyptians recorded soap recipes on their papyri; they used it primarily as a remedy for skin conditions. They mainly bathed in scented water and rubbed themselves with natron, a kind of bicarbonate of soda found naturally in Egyptian lakes, which the Egyptians used for the preservation of mummies.
The Celts invented a soap made from beech ash and goat tallow.
Very early on, this mixture was adopted by the Romans, who used it as a bleaching agent on their hair. (This is why the Celts often had red hair.) Later, the Romans used it for its cleansing properties.
It is to the Arabs that we owe the modern recipe for soap made from natural soda extracted from coastal plants.
Soap was the subject of a thriving trade until the 12th century and was sold at a very high price.
It was not until the 16th century that soap came back into the spotlight, as the Renaissance saw the body become visible once more. However, with the resurgence of epidemics and knowledge that bordered on the magical, perfume took over from soap.
It was not until the end of the 18th century that soap came back into the spotlight, with perfumed soaps becoming fashionable.
As living standards improved, with the advent of running water, hygiene became more widespread and soap became an everyday necessity for good health.
In the early 19th century, most soaps were made at home using cooking fats and butcher’s
fat.
In 1916, with a shortage of fat caused by the war, manufacturers developed synthetic soaps. Handmade soaps contain glycerine, which is known to moisturise the skin naturally. Industrial soaps do not contain glycerine; it is removed and sold separately.
Saponification values table
Soap: It is a chemical reaction between a base (soda) and an acid (fat) = soap + glycerine. The fats can be animal or vegetable. The base is soda or potash.
There are several methods of making soap; here are two of them:
The hot process:
Undoubtedly the oldest. Soda ash is gradually mixed with the fat and the mixture is heated for around ten hours at approximately 110 degrees C; it is then left to rest for 12 hours before being cut.
The cold process
Soda ash is added to water, left to cool to around 40 degrees, and then gradually poured into the fats. This mixture is stirred until the ‘trace’ stage is reached – that is, once the liquid has become opaque and thickened, it is time to pour it into the moulds.
This method best preserves the qualities of the oils.
Wait 5 to 6 weeks before using.
pH
pH measures the acidity or alkalinity of a solution
. A pH of 7 is neutral. The skin’s pH is between 5.5 and 6. Handmade soap has a pH of around 9–10. Industrial soap has a pH of between 5.5 and 7 and dries out the skin.
INS factor: if it is high, the soap is too hard; if it is too low, the soap is too soft. Animal fats have a fairly good INS factor for soap-making, whilst of the vegetable oils, only palm oil andolive oil are suitable on their own for soap-making; the others must be blended.