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Other articles of the Solid Shampoos series:
In this article, I will list the steps that I follow when I produce a solid shampoo. You can follow these steps if you reproduce any of my solid shampoo formulas. If you follow someone else’s formula, please follow their own guidelines!
- Double boiler (water bath) or hot plate
- Beakers (at least 3, a big one, a medium-big one, and a small one)
- Glass rods, spatulas or spoons
- Dust mask (important!)
- Lab gloves
- Soap moulds
- Optional, if you use SCI in needles form instead of powder: a grinder or a mortar with pestle
- Wear protections, especially the dust mask. This is VERY important, since solid surfactants are very dusty and you should not breathe them.
- (Optional) Smash the sodium cocoyl isethionate, if it’s not in powder form. I do it with a grinder, it’s possible to do it also with a mortar and pestle if you’re using small amounts.
- Prepare A (surfactants): transfer the solid surfactants in the big beaker (in my recipes: sodium cocoyl isethionate and sodium lauryl sulfoacetate). Then add the liquid surfactants (in my formulas: cocamidopropyl betaine and coco glucoside). Mix with a glass rod or a spatula: you will get a sort of paste.
- Prepare B (conditioning agents and fats): scale the components of B and transfer them in a medium-big beaker.
- Heat A and B. Heat beakers A and B on a water bath or hot plate until the components of B are completely melted. A will not melt, but it’s useful to heat it up such that it’s roughly at the same temperature as B.
- Prepare C: meanwhile, prepare the components of C (typically, the preservative).
- Mix A and B: when B is melted, add it to A and mix with the glass rod or the spatula to incorporate it.
- Add C. Incorporate the component(s) of C to the paste. The pH of the mixture should be already “the right one”, around 5.
- Transfer in the soap mould.
- Wait. Place the mould in the fridge and wait some hours for it to cool down. After some hours you can remove the shampoo bars from the mould. I suggest to wait a day or two before using them.
Note on formulas that include powders
There are two ways to incorporate powders in the shampoo:
A. Addition of the powders at the end, as D phase. I did this at the beginning, it works but it’s very tough to incorporate them well in the paste.
B. Addition of the powders to B before mixing A and B. That is: scale the powders separately, then as soon as B is melted, add them to B. Mix well to suspend the powders, then proceed with the addition of B to A.