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:

  • detergent agent (or cleaner): i.e. able to remove impurities or dirt

  • 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

  • wetting agent: this type of agent allows a greater spread of a liquid on a solid

  • emulsifying agent: an emulsifier makes it possible to mix two immiscible liquids, for example water and oil, and to thus form an “emulsion”

  • 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:

  • 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
  • amphoteric surfactants: with two charges, one positive and one negative. Examples include Sodium Lauriminodipropionate, Disodium Lauroamphodiacetate, or Cocamido propyl betaine (most popular).

  • 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:

  • sodium lauryl sulfate (SLS), which is very irritating

  • sodium laureth sulfate (SLES), which is less irritating

  • 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:

  • sodium cocoyl glutamate, which is very expensive

  • sodium coco sulphate (SCS), a sulphated derivative of the fatty acids in coconut oil

  • 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

  • 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
  • Because you know exactly what goes in it

  • 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

Before you start making your own cosmetics, please, read these warnings :
• Some ingredients may be allergenic: always perform a preliminary test applying your preparation over about 1 cm² in the crook of your elbow
at least 48 hours before using your preparation in order to ensure that no reaction occurs (stinging, redness, difficulty breathing etc.).
• All cosmetics containing an aqueous phase (water, hydrosols) are very liable to microbiological contamination. So, it is essential to manufacture
your home-made creams in very hygienic conditions.
1. Sanitize the utensils and containers before use: either by immersing them in boiling water for 10 minutes (excluding plastic containers and pumps)
and drying them thoroughly with a clean and dry cloth, or by rinsing them with pharmacy alcohol (excluding gloss containers that are not alcohol resistant : sterilize with boiling water) and air-drying them.
2. Wash your hands before getting started and wear clean gloves.
3. Avoid touching the preparation and ingredients with your hands.
4. Store the temperature-sensitive preparations in cool conditions and use them quickly.
5. Use tested «natural preservatives»
6. Immediately throw away any preparation if you notice the slightest amount of mold, an objectionable odor or changes in its appearance etc.
• It is sometimes necessary to heat certain raw materials up to a high temperature. The precautions for use must be respected to avoid burns. It is advisable to wear eye protection.
• Always carefully label and date your preparations and keep them out children’s of reach.
• Respect the indicated doses. When making your product, fill in a traceability book, note the composition of your product and the batches
of ingredients used, as well as the manufacturing date.

Instructions

To make your own solid shampoo, follow the following instructions step by step:

  1. In a double boiler, heat the surfactant with a little water (or hydrosol), and the oil and/or butter.
  2. Stir constantly. The heat will melt the butter and soften the sodium coco sulfate. Once melted, remove from heat.
  3. Crush the mixture to form a fairly homogeneous dough. Sodium coco sulfate “vermicelli” may still be visible, but it is not a problem.
  4. For variations of the recipe, add powders, essential oils and other ingredients at this stage.
  5. Transfer the dough to a previously oiled soap mold and press down to spread it all in the mold.
  6. Allow the shampoo to harden before unmolding it. (You can optionally put the preparation in the freezer for 10 minutes).
  7. 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!