How to make soap with clay?

Our Tips for Choosing the Best Clay for Soap Making

Do you make cold-process soap and are you looking for a natural color instead of a synthetic dye? Clay is one of the best options: it adds color and it brings active skin benefits (absorbing excess sebum, gentle exfoliation, minerals).

This guide brings together the clays used in soap making, their properties, the skin types they suit, and the method for incorporating them into your soap batter.

Why add clay to a soap?

Beyond color, clay brings several concrete benefits to a cold-process soap:

Property	Effect on the soap / the skin
Absorption	Captures excess sebum and impurities, like a sponge
Adsorption	Retains toxins and impurities on its surface
Cation exchange (CEC)	Removes unwanted positive ions while releasing beneficial minerals (calcium, potassium)
Gentle exfoliation	The fine particles remove dead skin cells
Soothing	Certain clays (white, pink) calm the skin
Mineralization	Provides silicon, calcium, magnesium
Fragrance fixative	Extends how long the scent lasts in the soap
Texturizer	Adds softness and "slip" to the lather
Trace accelerator	Absorbs moisture and thickens the batter, which speeds up hardening

All our clays are 100% mineral in origin and comply with the ISO 16128-1 standard (NI = 1; NOI = 1). They are raw materials that can be included in formulations eligible for COSMOS certification, subject to validation by the certifying body and compliance with the requirements of the applicable standard.

Comparison Table: Which Clay Should You Choose for Your Project?

Your goal	Recommended clay	Color in the soap	For which skin types?	Its main strength	Ideal for…
A soap for combination-to-oily skin	Green Montmorillonite Ventoux	Green	Combination to oily skin	Very strong exchange capacity (CEC), gives excellent slip	Shaving soaps, soaps for oily skin
A purifying soap	Illite Bonneval	Beige to light green	Oily, blemish-prone skin	High absorbing power	Soaps for blemish-prone skin
A soap with a healthy glow	Yellow kaolin de Vala	Ochres Yellow	All skin types	Beautiful natural, luminous tone	Face and body soaps
A soap with warm tones	Red Illite Fronnac	Brick red	All skin types	Naturally rich in iron oxides, deep color	Decorative soaps or "healthy glow" effect
An original color	Illite Orange des Cimes	Orange	All skin types	Also rich in iron oxides	Decorative artisan soaps
A very gentle soap	White Kaolin Izane / White Kaolin Morélie	White to cream	All skin types, especially the most delicate	Very fine texture, softness, improves the feel of the lather	Face soaps, family soaps, sensitive skin
A delicate, elegant soap	Pink Corens / Pink Clinchant	Powder pink / Salmon pink	Sensitive or mature skin	Fine grain, very light exfoliation	Care soaps and premium soaps
A soap with mineral shades	Bleu du Sud (Blue)	Blue	All skin types	Original natural color	Artisan and decorative soaps
A solid shampoo	Rassal	Beige	Hair and scalp	Natural cleansing power	Solid shampoos, dry shampoos, body soaps
A soap with a mineral style	Terre de Sarval	Gray to black depending on moisture	Oily skin	Strong absorbing power and intense color	Purifying soaps
A soap with original shades	Bentonite Lilas de Sensy	Chocolate brown	All skin types	Rich texture and evolving color	Artisan soaps
A very absorbent soap	Ghassoul	Beige	All skin types	Very strong absorbing power, soft feel	Soaps, solid shampoos, and cleansing care products
A natural purple color	Violette Frontenac	Purple	—	Color is not stable in cold-process saponification	Reserve for balms, powders, or creams
A household stain-removing soap	Terre de Sommières	Beige	Non-cosmetic use	Excellent absorption of fatty substances	Household and stain-removing soaps

Experiment with different clays to discover the combinations of colors and properties that perfectly match your needs and preferences.

Detailed Guide, Clay by Clay

1. Green Montmorillonite Clay Ventoux

Color: Green

Composition: 100% mineral

This is the queen of clays.

Montmorillonite is one of the most sought-after clays in artisan soap making. It has a very strong cation exchange capacity (CEC), along with excellent absorbing and adsorbing power. This particular structure also allows it to swell on contact with water, a characteristic property of smectites.

In saponification, this water-retention capacity adds more slip and smoothness to the lather. That's why it's especially prized in shaving soaps.

Its natural green color makes it possible to achieve soaps with plant-like tones without any synthetic dye. Traditionally, it's favored in formulas intended for combination-to-oily skin thanks to its strong absorbing power.

In chromotherapy, green is traditionally associated with balance, nature, and harmony. This symbolism can reinforce the identity of a soap inspired by the plant world.

2. Illite Clays

Illites form a family of natural clays whose shades vary according to their content of iron oxides and various minerals (potassium, magnesium, calcium, sodium, silicon...). This diversity offers a wide color palette that is highly valued in soap making.

Illite Bonneval Clay

Color: beige/light green Composition: 100% mineral

Thanks to its good absorbing power, this clay is often used in soaps intended for combination or oily skin. It helps give a clean-skin feeling after washing and adds a soft, natural tint to soaps.

Yellow Illite Auban Clay

Color: dark ochre yellow

Composition: 100% mineral

This clay provides a warm, luminous coloring. It's prized for creating soaps with natural tones reminiscent of earth and sun.

In chromotherapy, yellow traditionally symbolizes light, optimism, and energy. It evokes warmth and good spirits, which can influence the sensory perception of the product.

Red Illite Fronnac

Clay Color: brick red

Composition: 100% mineral

Naturally rich in iron oxides, this clay gives soaps a deep, warm color. It's often used in formulations meant to create a "healthy glow" visual effect.

In chromotherapy, red is associated with vitality, energy, and dynamism.

Illite Orange des Cimes Clay

Color: dark orange

Composition: 100% mineral

This clay offers a bright, warm color especially prized in decorative soaps.

The intensity of the shade depends on the formulation: light-colored oils bring out the color more, while darker oils produce more subtle shades.

In chromotherapy, orange is traditionally associated with creativity, conviviality, and joy.

3. White Kaolin Clay

Color: white to cream

Composition: 100% mineral

Kaolin is one of the gentlest clays used in cosmetics.

Its very fine grain gives the soap a soft feel while improving its texture. It's particularly well suited to soaps intended for delicate skin.

In soap making, it also helps improve the slip of the lather, which explains why it's frequently found in shaving soaps.

Its light color makes it possible to create white or pastel soaps and provides an excellent base for natural coloring.

In chromotherapy, white evokes purity, simplicity, and serenity.

4. Pink Clay

Color: pink

Composition: 100% mineral

Pink clay combines the fineness of kaolin with the absorbing properties of illite.

Highly prized for its delicate color, it's used as a natural mineral colorant in artisan soaps. Its very fine texture provides a particularly gentle exfoliation.

It suits all skin types, especially delicate skin.

In chromotherapy, pink is traditionally associated with softness, calm, and comfort.

5. Blue Clay ("Bleu du Sud")

Color: blue

Composition: 100% mineral

Rare in soap making, this clay makes it possible to achieve an original mineral coloring.

It's used both for its aesthetic appearance and for its fine texture, which blends easily into formulations.

It suits all skin types.

In chromotherapy, blue evokes calm, freshness, and serenity.

6. Rassal Clay

Color: beige

Composition: 100% mineral

Rassal has traditionally been used for hair and skin care.

Its strong cleansing power makes it a particularly popular ingredient in solid shampoos, dry shampoos, and certain body soaps.

Its texture provides a pleasant feeling of cleanliness while preserving skin comfort.

7. Black Clay ("Terre de Sarval")

Color: gray when dry, black once moistened

Composition: 100% mineral

This clay is prized above all for its very distinctive visual appearance.

Its strong absorbing power makes it an excellent choice for soaps intended for oily skin.

In chromotherapy, black evokes depth, sobriety, and elegance.

8. Lilac Bentonite Clay ("Bentonite Lilas de Sensy")

Color: lilac when dry, chocolate brown when moistened

Composition: 100% mineral

Like all bentonites, this clay has strong absorbing power thanks to its montmorillonite-type structure.

Its evolving color creates an original visual effect during soap making.

It's prized for creating soaps with a silky feel and excellent slip.

9. Ghassoul Clay

Color: pinkish beige

Composition: 100% mineral

Originating from Morocco, ghassoul has been used for centuries in traditional hammam treatments.

Contrary to what is often written, ghassoul is not a montmorillonite. It is mainly composed of stevensite, another mineral belonging to the smectite family.

It has a very strong absorbing capacity while retaining an exceptionally soft texture.

Very rich in magnesium, it's widely used in hair care, masks, and artisan soaps.

In chromotherapy, its beige color evokes softness and naturalness.

10. Violet Frontenac Clay

Color: purple

Composition: 100% mineral

This clay is mainly used to add original coloring to cosmetics such as balms, powders, shampoos, or certain decorative preparations.

⚠️ In cold-process saponification, its color is unstable. It is therefore not recommended for this technique.

In chromotherapy, purple is associated with creativity, imagination, and meditation.

11. Terre de Sommières

Color: beige

Composition: 100% mineral

Use: exclusively household (non-cosmetic).

Terre de Sommières is a natural clay renowned for its very high capacity to absorb fatty substances.

Incorporated into a household stain-removing soap, it helps make it easier to clean greasy stains on fabrics and certain washable surfaces.

How to Incorporate Clay into a Cold-Process Soap

Clays are easy to work into a cold-process soap recipe, provided you follow a few simple rules. They add natural coloring, slightly change the texture of the lather, and can influence the consistency of the soap batter.

1. Determine the right dosage

A concentration of between 1 and 3% of the total weight of the oils works for most recipes.

For example, for a recipe containing 25 kg of oils, plan for about 250 to 750 g of clay.

A higher dosage is possible depending on the effect you're after, but it can make the batter thicker and the soap firmer.

As with any formulation, use a lye/saponification calculator and always weigh every ingredient with a precision scale.

2. Sift the clay

Pass the clay through a fine sieve to remove any clumps. This step makes it easier to disperse and helps achieve a perfectly smooth batter.

If you're using a fragrance, some soap makers prefer to mix it with the clay a few minutes before adding it in, to encourage even distribution throughout the batter. This practice is based on experience and can vary depending on the formulation.

3. Prepare a smooth paste

Before adding it to the soap batter, mix the clay with a small amount of oil taken from the recipe.

A ratio of about 1 part clay to 3–4 parts oil generally produces a smooth paste, free of lumps.

4. Incorporate at trace

Add the clay paste once the mixture reaches a light to medium trace.

Gently mix with a whisk or spatula until the color is uniform.

Certain clays, particularly montmorillonites, can slightly speed up the thickening of the batter. It's therefore a good idea to have your molds ready before this step.

5. Pour and let it saponify

Pour the batter into the molds right away, then continue with your usual saponification, unmolding, and curing process.

Since every oil, fragrance, and clay can influence how the batter behaves, take the time to observe the final result.

A Few Tips for Successful Trials

• Always wear gloves and safety goggles, and follow the safety rules for handling lye.

• Make small test batches first before larger production runs, to make sure the soap meets your expectations in terms of texture, color, and properties. Ask us for our 15 g samples.

• Always note the type of clay used, its dosage, the oils used, and your observations. This formulation notebook will quickly become a valuable tool.

• Use utensils dedicated to soap making. Some strongly colored clays can stain equipment.

• Work in a clean environment to limit any risk of contamination during production.

• Dosage: count 1 to 3% of the total weight of the recipe (250 g to 750 g for 25 kg). Too much clay makes the soap excessively hard — start small and adjust. Always check your recipe with a soap calculator, and weigh every ingredient on a scale (never by volume).

• Sift: pass the clay through a fine sieve, then add the fragrance and let it sit while you prepare the rest — this helps the scent set.

• Dilute: mix the clay with a little oil to get a smooth, lump-free paste (about 1 part clay to 4 parts oil).

• Incorporate: add the clay paste at trace and mix evenly with a whisk or spatula.

• Pour: pour into the molds as usual — the clay thickens the batter and can speed up molding.

• Tip: note your proportions and observations for each trial so you can fine-tune your future recipes.

  
  

Additional tips:

• Follow the proportions and safety steps when making soap.

• Wear gloves and safety goggles.

• Always test your recipes: before producing in bulk, always make small batches and test them to make sure the soap meets your expectations in terms of texture, color, and properties. Ask us for our 15 g samples.

• Use dedicated equipment: keep in mind that clay can stain certain utensils, so it's recommended to use equipment dedicated to soap making.

• Follow good hygiene practices: make sure you work in a clean, sanitized environment to avoid any contamination of your soap.

  
  

Frequently Asked Questions

Which clay should I choose for oily-skin soap? Green Montmorillonite clay or Illite Bonneval, both purifying and sebum-regulating.

Which clay for sensitive or mature skin? Pink clay or White Kaolin clay, known for their gentleness.

Can violet clay be used in a soap? No, it is unstable in cold-process saponification. It's reserved for no-cook care products (lotions, balms, shampoos).

What's the right clay dosage in a soap recipe? Between 1 and 3% of the total weight of the soap batter.

Take Action

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