A soap is made from a mixture of oils or butters and lye or potash.
Soap is simply an assembly of :
- a base (lye detergent)
- a fatty substance (such as vegetable oils or butters)
Saponification is the chemical reaction between fats; AND a strong base.
The addition of excess oils means that they will not be processed with lye. The result is a over-fated soaprich in glycerin with oils that still have all their virtues.
A soap is made by this natural chemical reaction. The fact of doing it COLD, gives a product very rich in unsaponifiable, soft and moisturizing (unlike industrial soaps).
The soap is then poured into moulds, cut after 48 hours and will need 4 to 6 weeks of drying to harden well and thus last longer.
The difference with the soap pellets
What anyone can do today to easily produce their own soap is to buy bondillons. That is to say fats already saponified but free of their glycerin. It’s an excess of soda that actually removes glycerin, while accelerating the process of saponification. Saponification is referred to as “hot” saponification, although it takes place “cold” (i.e., chemically).
So it’s “pure” soap, without its fat, in other words, a detergent. This cleanses the skin, of course, but especially removes the layer of sebum (oily film). The sebum is secreted naturally and protects your skin from drying out and prevents the potential formation of cracks that would allow foreign objects to enter the body.
It should be noted, however, the existence oftraditional saponification in the cauldron, which is based on the principle of soft cooking with external heat input.
Two well-known soaps use this method:
- Aleppo soap, which has a geographical indication controlled by Syrian law. It is made from olive oil and bay oiland dried for at least nine months.
- Marseille soap based on vegetable oils, born from the industrialization of the manufacture of soap in the south of France, it has no control over the geographical origin. Cooked in a cauldron according to a specific methodology (called «Marseille process») and long (between one week and ten days) in the Bouches-du-Rhône by only four soap makers at the beginning of the 21st century(i.e. the soap factory of ‘Fer à cheval’, the soap factory ‘Le Sérail’, the soap factory of ‘Midi’, and the soap factory ‘Marius Fabre’, united under the acronym UPSM for Union des professionnels du savon de Marseille).
Difference between commercial soaps
Soap manufacturers buy large bags of bondillons made from oils or butters already saponified and inexpensive, such as animal fats or palm oil.
They melt those soap pellets in a bain-marie and add dyes, perfumes and, possibly, glycerine to limit adverse effects on the skin.
The manufacturing process has a much greater impact on the environment (consumption of water, electricity, and of course the use of less environmentally friendly products such as palm oil).
The manufacture via cold saponification transforms oils and butters while keeping their properties intact.