Clays are wonderful ingredients for adding to cold process soap. They are reported to bind to essential and fragrance oils to assist with fragrance longevity. They are also an ideal ingredient with a variety of apparent healthy benefits and properties (info given below), as well as the extra benefit of adding to the colour of your soap.
There are many clay sources in the world - we will only be referring to Australian and Brazilian clay in this post. French clay is also highly sought after by many soap makers and its omission from this post is no reflection on this beautiful product.
How Much Clay to Use in Cold Process Soap
It is recommended to use at least one teaspoon per pound (453 Grams) of soap oils. If you prefer a darker colour, add a little more.
Be aware that clays will also draw moisture, so it is highly recommended to 'wet' your clay (mix to a paste) with purified or distilled water prior to adding them to your batter.
For a single colour soap you can add the clay to your lye solution, this will promote a greater intensity in the colour. Alternatively, if you would like a subtle swirl effect in your soap, you will need to add the clay once your soap batter is at a thin trace.
Why Use Clay to Colour Cold Process Soap?
Clays are considered to be a natural colourant for soap and are particularly great when creating vegan friendly products.
Clays are not affected by the soap pH, whereas some Micas or other colourants can change colour during the process. For example: a green Mica may turn to a brown hue, a purple Mica may change to a grey hue (obviously this will depend on the brand used).
There is no 'bleed' affect from clay in the soap. If you are adding the powdered clay to your batter you may notice tiny spots of clay in the completed soap. You may like this effect.
When using clays for colouring soap, the colour will remain stedfast as they do not fade over time
There are many colour clays available to enable a variety in soap hues
White Kaolin Clay
Australian Kaolin White Clay is the most gentle of all the clays and is used in many skin care products because of its absorbency properties. It is a world class clay sourced from pure kaolin ore.
It is the mildest of the clays and as such is well suited for all skin types, particularly mature, delicate, sensitive and oily skin.
Australian Kaolin White Clay is used to purify, cleanse and detoxify the skin, balance skin oils and calm inflamed and acne-prone skin.
Pink Australian Clay
Pink Clay is used to purify, cleanse and detoxify the skin, remove dead skin cells, improve skin softness and create and overall refreshed appearance.
It can also be used to treat acne and sun damaged skin.
It is well suited for all skin types, particularly sensitive and mature skin.
Pink Clay can be used in soap making to add its wonderful properties and to colour the soap naturally.
Green Australian Clay
Green Clay is a powerful, mineral rich, healing clay.
Although sourced in Australia it is also the most popular of the French Clays. It is rich in minerals and has revitalizing and regenerating properties. It tightens pores, cleanses, absorbs excess sebum from the skin, and removes impurities, stimulating blood flow to create healthy and glowing skin. It is your go-to for exfoliation, pore-tightening and oil-absorption.
Yellow Australian Clay
Yellow Australian Clay is great for gently exfoliating and cleansing your skin, toning and strengthening connective tissues, stimulating blood circulation, drawing out toxins and superfluous fat, and hydrating your skin, without leaving it feeling dry or tight. Yellow clay is mild making it ideal for all skin types, including dry and sensitive. It can be used to incorporate its beautiful benefits as well as colour in soap making.
All Brazilian clays are forms of kaolin clay, which naturally occurs in hot, wet climates. When mixed with water, this clay creates a slurry suspension. It is light and fine, and its color varies depending on the presence of certain elements when it forms.
Black Brazilian Clay
Brazilian clays add a wonderful silky lather to soaps. They impart the most color in gelled cold process soaps. The mica present in Brazilian clay is not added and occurs naturally in the mining process.
Black Brazilian clay helps in the removal of dirt from the skin and is a natural source of magnesium, copper, zinc and selenium.
Purple Brazilian Clay
Purple Brazilian Clay is particularly good for sensitive skin and is a great way to add an all natural colour to your soap. It is a natural source of magnesium, copper, zinc and selenium.
Purple clay benefits are mostly anti-aging. Purple Brazilian clay can also help prevent your skin from absorbing environmental contaminants and impurities. That is why purple clay is one of the most popular natural clays for soap.
Pink / Rose Brazilian Clay
The minerals that give this clay its lovely natural color include copper, selenium, manganese magnesium and zinc. It's popular for use in soaps, because it helps form a smooth, rich lather and offers mild exfoliating properties. Pink Brazilian clay is prized for being one of the mildest clays available. It is ideal for people with very sensitive or delicate skin as it has a pH very close to that of human skin.
Yellow Brazilian Clay
Yellow clays often include feldspar, also called aluminum silicate. It's a soft, mild clay that doesn't absorb oil like the other colors of clay. That makes it perfect for sensitive or dry skin. You will often find increased amounts of silicon, titanium and potassium in this clay, which can promote increased collagen production. Some people also believe it can help remineralize the skin, making it stronger and healthier.
Red Brazilian Clay
Red clays are higher in iron, which softens skin almost instantly upon use. It can help repair cutaneous effects of the natural aging process as it has been reported to greatly lift and firm the skin.