Autumn is the season when I always reformulate at least one cleansing product. As environmental stress increases and humidity drops, I look for systems that can purify the skin without compromising barrier comfort. This is exactly why I love combining cosmetic clays with donkey milk in a soap matrix.
Clays offer controlled adsorption of excess sebum and pollutants through their mineral surface activity. Donkey milk, on the other hand, contributes bioactive components such as proteins, lactose, phospholipids and naturally occurring lipids that support skin softness and barrier comfort. While rinse-off products do not “stimulate collagen” in the biological sense, milk-derived components can improve skin feel and help reduce tightness after cleansing.
The goal of this formulation is not aggressive detoxification. It is balanced purification.
This soap gently removes surface impurities and excess oil while maintaining a smoother, more comfortable skin finish. It is suitable for both face and body, provided the clay type is selected according to skin type.
If you are unsure which clay matches your skin needs, click here to read my detailed guide on choosing the right clay based on mineral properties and skin type.
Clay & Donkey Milk Melt and Pour Soap
100g | 100% white soap base with donkey milk
5g | 5% clay (selected according to skin type)
1g | 1% essential oil (IFRA-compliant) of your choice
or
2,5g | 2.5% fragrance oil (for seasonal variations, I used autumn-inspired fragrance profiles such as fig, apple, orange, bitter almond, almond milk and pumpkin spice)
tools required99% isopropyl alcohol in a spray bottle
silicone mold
cutting board
knife
heat-resistant beaker
electronic thermometer
precision scale
alcohol spray bottle
whisk
plastic wrap
preparation process
Before starting, I sterilise all tools, molds and surfaces. Even though this is a melt-and-pour system, hygiene matters for product stability.
I weigh the soap base accurately and cut it into uniform cubes. Smaller pieces melt more evenly and reduce overheating.
The cubes are placed in a beaker and melted in a bain-marie at low temperature. Overheating can degrade volatile fragrance components and affect texture, so I always keep the temperature controlled.
Once fully melted, I gently stir to ensure uniform consistency. At this stage, it is important not to incorporate excessive air.
The selected clay is then dispersed into the melted base. Technically, the clay does not dissolve; it disperses. Proper dispersion is essential to avoid clumping and ensure even mineral distribution. If necessary, a short pulse with a mini mixer can improve uniformity, but overmixing introduces bubbles.
I monitor the temperature carefully. At approximately 55°C, I add the fragrance. Adding fragrance at excessively high temperatures can lead to volatilisation and scent loss.
Alcohol is sprayed on the surface to eliminate air bubbles. I also spray the mold lightly before pouring to ensure a smoother surface finish.
The soap is poured into the mold and sprayed again to remove surface bubbles. It is left to set at room temperature.
Once fully solidified, I unmold and wrap it in plastic film to reduce moisture loss and preserve fragrance stability.
usage & skin considerations
This soap is intended for use up to twice per week when formulated with higher-adsorption clays such as smectite-rich systems or bentonite. For kaolin-based versions, more frequent use may be tolerated.
Unlike masks, soap lather should not remain on the skin for extended periods. A brief contact time is sufficient for surface cleansing. Prolonged exposure may increase transepidermal water loss, particularly when using high CEC clays.
After cleansing, applying a lipid-supporting moisturizer is recommended to maintain barrier integrity.
