A little chemistry ?
A short explanation of the Cold Process Saponification (CPS):
The saponification is a chemical reaction between an "alkali" (a basic liquid) and a fatty substance (vegetable oil, butter, grease) who produce soap and glycerin. Alkali is obtained by solution of lye or potash in water.
Here, at "Un savon sous la Yourte", we are working with caustic soda (also known as NaOH). This soda is today obtained bye an industrial electrolysis of a brine process, but the process of the alkali production is knew by the greek antiquity (obviously without electricity ... but with water, ferns ashes and a calcareous slab). With caustic soda, we obtain some solid soaps, not like with the antic potash who make limp soap.
The chemical reaction related to the fatty substance emulsion in the lye transforms elements in soap and glycerin. The soap, by his molecular composition ans when it's dissolved in water, has the capacity to disconnect fat from their support to the point of saturation. Soap pH is between 8 and 10. Below pH 8, it isn't soap, but a "washing bar" or a "shampoo" whose raw materials can only be obtained by complex industrial process. Beyond pH 10, soap is corrosive and dangerous for the skin and metals. It's because this last reason that our soaps are routinely verified on leaving process.
The Cold Process Saponification method has a particularity : toilets soaps cut out the soap bar must dry at least for 4 weeks. This is what we call in french "la Cure" - I'm not sure of the right term in english, but it's fun in french, isn't it ? - during witch time the chemical process will end and the soap drying. All CPS soapmakers will says the same thing (in France at the very least) : "A good soap, it's like a good cheese : it has to matures."
At "Un savon sous la Yourte", we've got all our time ...
... to prepare yours high quality soaps !
So ... what are the differences between cold and hot processeses of saponification ?
A little bit of method ...
The emulsion process is the same. But the method vary ...
In the traditional industrial process, for making "Marseille" or "Alep" soaps, the emulsion is heated. Indeed, the mixture of oils and lye is heated at 110°C for 12 hours with the aim of fast forwarted the process to save time... and money. After this first 12-H time, the mass is reduced to shavings who will be later melted again. In the same time, all the glycerin is removed (because glycerin = cosmetic gold!). After that, a new process begin : the neutral soaps ships are mixed with perfume, dye, glycerin (only 0,1% !) and other additives then extruded in bars.
Under this circumstances, all the oils and butters best features are lost ... A vegetable oil is cooked between 60 to 70°C. With no glycerin, soaps are less quality, but melt away more slowly and have a great lather. Soaps made with this process are more aggressive and dries out for the skin... this soaps require adjuvents, and, at the end of your shower, you need a shot of moisturising cream made with the same glycerin removed out of your soap ...
In Cold Process Saponficiation, vegetables oils aren't heated. Only butters and waxes are melted around 45°C max to be able to mix them. The chemical process isn't enforced, the temperature naturraly gradually increases to reach 60°C (saponfication is an exothermic reaction). Colourings, essential oils and clays are mixed in the stable emulsion as soon as possible. The mass cools down as slowly as possible, for 24 to 48 hours. Once the mixture cooled down, toilet soaps are hand-sliced and stocked for 28 days, "la Cure" (in french, please).
The SCP soaps that came out of "Cure" were not overheated, and 7% of glycerine is naturally present. All the benefits of the oils are preserved !
The manufacturing method is totally hand made: you will not find any "Marseille" soap shavings in the soaps made by Un savon sous la Yourte. You will not find soaps where the oils are cooked at a temperature higher than 60°C, before, during or after the emulsion.
The soap is made according to the "cold saponification" method, following to the letter the specifications of the french Association des Nouveaux Savonniers (ADNS) - i.e: New soapmakers association)
Un savon sous la Yourte
La douceur de l'itinérance
The softness of nomadism