Guide
Cold-process soap or industrial soap: what is the difference?
The difference is glycerine and temperature. In cold process the oils are never cooked, and the glycerine created by the reaction stays in the bar, where it holds water against the skin. In industrial production the paste is worked hot and the glycerine is often separated out, because it has value of its own, then replaced by other agents.
The comparison, point by point
| Cold process | Industrial soap | |
|---|---|---|
| Glycerine | Stays in the bar | Often separated and sold on |
| Temperature | No cooking, worked at low temperature | Worked hot |
| Superfat | Part of the oils stays unsaponified | Rare, agents are added afterwards |
| Time | At least 8 weeks of curing before sale | A few hours from paste to wrapper |
| Ingredient list | Short, every line is recognisable | Longer, with surfactants and fillers |
| Batch size | Small batches, bar by bar | Continuous production |
What changes in the shower
A cold-process soap gives a denser, less abundant lather: lather is not a measure of cleaning, it depends on the surfactants. It leaves the skin feeling less tight, because the glycerine and the unsaponified oils stay where they are.
It is also softer to the touch and takes up water more easily. That is why it needs to dry between uses, otherwise it wears down fast.
How to recognise one when you buy
- Look for "cold process" or the French "saponifié à froid", sometimes shortened to SAF.
- In the INCI list, cold-process soaps start with entries such as SODIUM OLIVATE or SODIUM COCOATE, the saponified oils, and contain GLYCERIN without it having been added.
- If the list opens with SODIUM PALMATE and goes on with EDTA or TETRASODIUM ETIDRONATE, you are looking at industrial production.
- A handmade soap carries a production date or a batch number, because it is made in batches.
How a cold-process soap is made
-
1
The organic oils, weighed and poured cold. They are never cooked, and that is what preserves the qualities of the raw materials. -
2
The soap paste poured into the moulds, here GRENADA with its natural urucum colour. -
3
After 48 hours the loaf is unmoulded and cut by hand. Here AMARATERRA, with its stripe of vegetable charcoal. The bars then cure for at least 8 weeks.
How we work
Our soaps are cold-processed in our workshop in Drôme Provençale, with certified organic oils. After 48 hours the loaf is unmoulded and cut by hand, then the bars cure for at least 8 weeks before they are sold: that is the time saponification needs to complete and the bar needs to harden, which is what makes it last. Finally we wrap them by hand in recycled FSC paper. Five formulas, a 100 g bar at €9.90.