[Qui trovate la versione italiana con ulteriori spiegazioni]
More articles from the Solid Shampoos series:
I will make the long story short: solid shampoos are not soap bars.
And I will make it even shorter: I won’t explain much about how solid shampoos are made (or NOT to be made) because there are already not one, but three websites that explain perfectly everything you need to know about formulating solid shampoos.
These websites are:
What are they: solid shampoos are basically very concentrated versions of liquid shampoos. Imagine you take a classical liquid shampoo formulation, made of water, surfactants, sometimes oil, and some active ingredients, and take the water away. And now imagine that the surfactants are solid. What you get is something that looks like a soap bar, but is NOT. Because if you did read the article about soap making you should know that a soap is not made with the surfactants we use in shampoos, and that it has a pH of 8-11.
How they work: solid shampoos are very concentrated solid surfactants, packed together with or without additional oils and ingredients. But the surfactants are still soluble in water, therefore as soon as we rub them with our wet hands they will produce foam. And they wash our hair just as well as any liquid shampoo.
Why: if you buy a solid shampoo, you get a product that does not have any plastic packaging. Unless the company that sells them is stupid and packs them in plastic bags. In addition, since they are super concentrated, we use only a little portion each time and they last much longer than the equivalent shampoo bottle. This means less waste and less money spent.
If you produce your own solid shampoo, the plastic packaging story is a bit different. Reagents typically come with plastic bottles, bags or jars that you will eventually throw away. But with 500-1000 g plastic bag of the main surfactant I use (sodium cocoyl isethionate) I can make countless solid shampoos. I will eventually throw that plastic bag, but if I were using classic liquid shampoos I would have thrown away a lot more plastic bottles meanwhile.
Is it cheaper if I produce my own solid shampoo? In the long term, yes. But consider that you will have a little investment to make first, to buy the general equipment to make cosmetics at home and, of course, the reagents.
But the most important thing you have to understand now is just this: solid shampoos are NOT soaps. If you buy them and you read ingredients like: sodium olivate, sodium cocoate, sodium palmate, that’s a soap. Some companies insist selling soaps as shampoo bars and they’re wrong! If you accidentally bought a soap thinking it’s a shampoo, just use it for your hands or body. The mostly used surfactants in solid shampoos are for example: sodium cocoyl isethionate, sodium coco sulfate, sodium lauryl sulfoacetate, sodium C14-16 olefin sulfonate, cocamidopropyl betaine, coco- or decyl glucoside…. and some others.
In the Italian version of this article I analysed a bit more in detail how the recipe for a solid shampoo should be, because there are only few resources about this matter in Italian. But you, English-speaking reader, you should definitely read the blogs linked above!
If you want to see my solid shampoos recipes, click here.