A solid shampoo is simply a soap bar made from a base of oils chosen specifically for their hair and scalp care properties. The majority ingredient that differs from most soap bars is Castor oil. Also it is helpful to include oils such as Sweet Almond and Jojoba. This makes them more expensive to make than a simple soap. Our advice is to familiarise yourself with the techniques of soap making before moving into more complex recipes such as for solid shampoos.
The solution (now known as Lye) will heat up to nearly 200oF and will need to be left to cool. Place one of the thermometers into the solution and leave to one-side. If you want to speed the cooling, place the jug in a large bowl of cold water, being careful not to 'float' it.
Meanwhile, measure out exactly 8oz (227g) of coconut oil and 6oz (170g) of palm oil into one of the saucepans (the smaller if there is one) and gently melt it on the stove. Don't overheat it, just melt it. When there are tiny pieces of solid oil still left to melt, turn off the heat and leave until completely liquid. If using a Lake or similar pigment to colour your soap, add a little to the warm oils now (see guide below).
Whilst the solid oils are melting, measure out 8oz (227g) of olive oil (pomace grade is best), 6 oz (170g) castor oil, 3oz (85g) sweet almond oil and 1oz (28g) jojoba oil into the other saucepan (this will be the soap-making pan).
Leave your solid shampoo 'curing' at room temperature for typically at least 3-4 weeks, preferably on a sheet of uncoloured absorbant paper allowing air to circulate around each bar or block. Curing will allow the soap to loose excess moisture and become harder.
Do not store your solid shampoo in a cold place. Soaps of all kinds will 'sweat' if cured or kept in a cold or cool place and then moved to a warmer one. Avoid 'sweating' by keeping your soap at a constant room temperature.
If packaging your solid shampoo, avoid absorbant paper or card coming into contact with it directly as any 'sweating' of the soap once packed will spoil the packaging. If you must use paper or card, wrap your soap first in something like waxed or siliconised paper or plastic film.
Suitable and simple-to-use colourants... Ultramarines: Oxides: Insoluble pigments which are used to colour the oils: Food-safe dyes (sold as water soluble powders)...e.g. Tartrazine yellow: Sunset yellow (orange): Amaranth red: many types of ground spices i.e. Turmeric: Paprika: Cinnamon.