Soap is a mixture of oils, water and sodium hydroxide (commonly known as soda). This reaction is generally carried out hot by manufacturers or for Marseille soap, and is possible cold with certain ingredients.
Cold saponification is the basis of the manufacture of many master soap artisans in order to best respect the properties of the vegetable oils added to the soap and to provide the skin with all the care it needs. Because it is the only process that allows to keep the glycerin naturally present in the soap.
During cold saponification, vegetable oils and caustic soda are mixed at a temperature between 35 ° C and 45 ° C, which makes it possible to preserve the virtues of vegetable oils and essential oils in the preparation.
This is the opposite of cooking in a cauldron for Marseille soap, where saponification takes place at a temperature between 80 ° C and 100 ° C.What is the difference with industrial soaps? Glycerin, which is a natural emollient!
From saponification, glycerin is a natural moisturizer. In the case of hot saponification (Marseille soap) and soaps made from "noodles", the so-called release stage rids the soap of glycerin, which it makes extremely sticky, a major obstacle on the industrial level. (it clogs machines and industrialists remove it and take the opportunity to resell it in the form of a moisturizer). The detergent power outweighs the emollient power: these soaps therefore tend to strip and dry out the skin.
You should know that industrial soaps contain only 1 to 2% glycerin, while artisanal soaps contain between 8 and 10%!
Ultra-rich soaps to provide hydration
The soaps of master soap makers are superfatted depending on the formulas (between 5% and 7%), that is to say that some of the oils are not saponified so that the soap hydrates more.
Cold saponified soaps are therefore suitable for all skin types, although some are particularly recommended for sensitive and fragile skin, dry or mature skin, oily and problem skin, as well as combination skin.
“I wake up early in the morning like the baker,” says Sidonie, “I dissolve my sodium hydroxide in the water. I weigh and prepare my oils: coconut to make the mousse, shea butter for its emollient qualities, rapeseed and sunflower from an organic farm 30 km from my home, olive from the Alda farm, a pure Portuguese woman whose brother operates a small farm there in Portugal, all organic. I work completely cold, which allows the soap to naturally retain 8 to 10% of its glycerin and the vegetable oils to retain all their properties. In a day I can only make 208 soaps of one scent. In fact, SAF (cold saponified soaps, Editor's note) is a bit like haute couture. Sublime pieces to wear in the shower while whistling. ", Sidonie Champagne, Sidonie Champagne Laboratory in Pays de Loire