Solid shampoos are an innovative and eco-friendly concept favored by many. It is a concentrated product, without packaging, without preservatives, which takes up little space and is easy to transport. A shampoo “bar” of 100 g (3.5 Oz) can make about 70 to 80 shampoos.
Solid shampoos can be fun to make because they can be molded according to your tastes and make very nice personalized gifts for your loved ones. These formulas can also be enriched very easily with butters or nourishing oils, which is more difficult with liquid shampoos.
The benefits of solid shampoos
*They do not take up space
*They are very easy to transport everywhere (no risk of leaking, no travelling restrictions…)
*They are zero waste, just a small box which is easily reused
*They are economical because they last much longer than a bottle of shampoo
*They are easier to dose, there is no risk of wasting it by pouring too much in the hand.
The drawbacks of solid shampoos
*Due to their solid nature, they contain a higher proportion of surfactants, which can in the long run become irritating or dry the scalp. Making the right choice in the ingredients, however, minimizes this problem related to surfactants.
*Between uses, they have to be kept in a cool, dry place, preferably on a soap dish. This will prevent the shampoo from being in prolonged contact with water. Otherwise, it may soften, or melt. Once dry, you can store them in a little tin box.
The surfactants
Definition:
A substance that tends to reduce the surface tension of a liquid in which it is dissolved. The surfactant compounds are amphiphilic molecules, that is to say they have two parts of different polarity, one lipophilic which has a high affinity with fats, the other hydrophilic which has a strong affinity with water.
Function:
Depending on their structure, surfactants can have different functions:
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detergent agent (or cleaner): i.e. able to remove impurities or dirt
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foaming agent: acting on the water-air interface, this type of agent allows the dispersion of a large volume of gas in a small volume of liquid and therefore the formation of foam
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wetting agent: this type of agent allows a greater spread of a liquid on a solid
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emulsifying agent: an emulsifier makes it possible to mix two immiscible liquids, for example water and oil, and to thus form an “emulsion”
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conditioning agent: this type of surfactant combines with keratin or skin to make them smooth and silky
Types of surfactants:
There are four types of surfactant compounds, which are grouped according to the nature of the hydrophilic part:
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anionic surfactants: the hydrophilic part is negatively charged (anion). These surfactants are particularly cleansing. Some common anionic surfactants used in hair care:
- sodium laureth sulfate, sodium lauryl sulfate and other sulfates (such as TEA lauryl sulfate),
- the carboxylate family: Sodium lauroyl sarcosinate, Sodium stearate
- the sulfonates such as sodium olefin sulfonate,
- sulfosuccinates such as Disodium laureth sulfosuccinate, disodium oleamine sulfosuccinate and sodium dioctyl sulfosuccinate
- and others such as Isethionates and Taurates.
- cationic surfactants: the hydrophilic part is positively charged (cation). Examples of cationic surfactants in shampoos: Polyquaternium-47, Polyquaternium-22, Polyquaternium-10
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amphoteric surfactants: with two charges, one positive and one negative. Examples include Sodium Lauriminodipropionate, Disodium Lauroamphodiacetate, or Cocamido propyl betaine (most popular).
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non ionic surfactants: the molecule has no charge. These are my preferred surfactants because they are not irritating and are biodegradable. These include Sodium Coco Sulfate, coco glucosides, Sodium cocoyl isethionate, Sodium lauryl sulfoacetate, Cetearyl alcohol, Cetyl alcohol, Stearyl alcohol
In cosmetics, synthetic surfactants derived from petrochemicals are regularly used, in particular:
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sodium lauryl sulfate (SLS), which is very irritating
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sodium laureth sulfate (SLES), which is less irritating
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ammonium lauryl sulfate (ALS), certainly the least irritating of synthetic surfactants
However, more and more natural surfactants are being used, especially in the making of organic/natural cosmetics. Those are:
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sodium cocoyl glutamate, which is very expensive
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sodium coco sulphate (SCS), a sulphated derivative of the fatty acids in coconut oil
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sodium cocoyl isethionate (SCI), a mild surfactant well tolerated by the skin, also derived from coconut oil. It is used to soften formulas based on sodium coco sulfate
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mild surfactants obtained from vegetable oils or sugar: coco glucoside, lauryl glucoside or decyl glucoside
Homemade
Why make it yourself?
- Because it’s more economical
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Because you know exactly what goes in it
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Because you can create a custom recipe specific to your hair type, and your preferences
- Because it’s a real pleasure, and also very rewarding to make your own little shampoo from scratch
The choice of ingredients
- A surfactant (sodium coco sulphate, sodium cocoyl isethionate…)
- Oils and/or butters (Castor oil, Shea butter…)
- Water and/or Hydrosol(s) (Lavender, Ylang Ylang…)
- Powders (Clays, Henna, Ayurvedic powders, Ghassoul, plant powders…)
- Active ingredients (Panthenol, Rice protein, Wheat protein, Maca…)
- Fragrance (Essential oils, fragrance oils, spices…)
The basic shampoo bar formula
Surfactant(s) (SCI, SCS…): 10 to 80%
Oil(s) and/or Butter(s) (Coconut oil, Shea butter…): 1 to 10%
Water/Hydrosol(s) (Rosemary, Mint, Ylang Ylang…): 5 to 10%
Plant extracts/powders (Nettle, Peony, Burdock…) : 1 to 10%
Clays (Kaolin, Ghassoul, Henna…): 1 to 10%
Essential Oils/Fragrances: 0.5 to 2%
Specific treatments (Panthenol, vegetal collagen, vegetal silicone…): quantities will vary based on product
Precautions
To make your own solid shampoo, follow the following instructions step by step:
- In a double boiler, heat the surfactant with a little water (or hydrosol), and the oil and/or butter.
- Stir constantly. The heat will melt the butter and soften the sodium coco sulfate. Once melted, remove from heat.
- Crush the mixture to form a fairly homogeneous dough. Sodium coco sulfate “vermicelli” may still be visible, but it is not a problem.
- For variations of the recipe, add powders, essential oils and other ingredients at this stage.
- Transfer the dough to a previously oiled soap mold and press down to spread it all in the mold.
- Allow the shampoo to harden before unmolding it. (You can optionally put the preparation in the freezer for 10 minutes).
- Let the shampoo air dry for 2 to 3 days before using it.
Preservation: well preserved and manufactured under optimal hygiene conditions, your product can be kept at least 6 months.
Happy shampoo bubbles to you!
Wow, this is so comprehensive and wonderful. Thank you!!!
Thank you Julie!
Hi Corinne
I have been making Shampoo bars with SCI and SLSa , usually with a lower liquid phase so that I get more of a play dough consistency that is easy to mold using a moon cake press or puc.
I recently purchased Sodium Lauroyl Methyl Isethionate (SLMI) without realizing that it has to be resolved in water. I have no idea how to formulate a shampoo bar with this. I have seen brand names selling shampoo bars with this as their only surfactant so I know that there must be a way. But I have no idea where to start to end up with a solid shampoo bar. I was thinking maybe you might have an idea?
This is the ingredient list of the store bought Shampoo bar using SLMI
Sodium Lauroyl Methyl Isethionate (Tensioactif issu de la noix de coco),Theobroma Cacao Seed Butter*, Althaea Officinalis Root**, Aqua, Oryza Sativa Bran Oil*, Chamomilla Recutita Flower Powder**, Calendula Officinalis Flower**, Glycerin***
Hi Mélanie,
SLMI is the new kid on the block amongst surfactants. It is a water soluble, coconut derived surfactant which contains no dioxane, nitrosamine or sulfates. It’s ultra foaming, very mild, has excellent rinsability and solubility, and is non toxic and non irritant. It is considered to be one of the safest on the market. Although very similar to SCI,it has to be handled a bit differently. First, it is not oil soluble. Second, the melting process is long and tedious. You have to add a liquid surfactant, such as sodium cocoyl glutamate, a little water (which will evaporate) and melt it at a fairly high temperature.
It will also take more time to harden than SCI.
To obtain a hard shampoo bar, you must use between 60% and 70% SLMI (which isn’t much given its great mildness). If you don’t want to use that much in your formula, you can add a hard butter such as cocoa butter (5% to 20%), and reduce the quantity of SLMI accordingly. You can also increase the amount of powders (plants, powdered milks, clays…) up to 20%.
Here is a basic formula which you can customize to your needs/preferences:
60% SLMI
10% Sodium Cocoyl Glutamate
10% Water
10% Cocoa Butter
5% Panthenol (or other active ingredients)
5% Powder (clay, plant, milk)
Plus your favorite fragrance or essential oil blend.
Melt the first 3 ingredients at a high temperature.
Take it off the stove and add the remaining ingredients, one by one.
Pour in mold and leave it in the fridge or freezer for a few hours.
Then remove from mold and let it dry in a dry, cool place for several days.
Hope this helps…Happy shampooing!