Foaming bath powder with SLSA

Before starting, prepare a large, clean and completely dry container. This matters because the recipe contains citric acid and bicarbonate: if moisture enters too early, the mixture may start to react.

Put on a mask, goggles and gloves before handling SLSA or any fine powder. This is not about making the recipe complicated; it simply avoids inhaling particles while weighing and mixing.

Now sieve the bicarbonate, citric acid, starch and clay. Do this slowly, without hitting the sieve hard, so that the powders remain loose and free from lumps.

Now add the SLSA with slow folding movements. Do not whisk it or stir energetically: the idea is to incorporate it gradually, raising as little powder as possible.

If you see an area with a large accumulation of SLSA, gently press it with the spatula against the powder mixture and fold again. It is better to take an extra minute than to create a cloud of powder on the worktop.

Once the previous mixture is incorporated, add the Sweet Almond Oil drop by drop or in a very thin stream. Adding it slowly distributes it much more evenly and avoids greasy clumps forming in one area.

Mix after each small addition. The final texture should remain a loose powder, slightly silkier to the touch, but neither damp nor clumped.

If you notice compacted areas when pressing with the spatula, break up these small lumps and keep mixing until the appearance is uniform.

As this is an anhydrous formula, pH is not measured directly on the dry powder. The correct approach is a small use test: take a representative sample, for example 1 g of product, and disperse it in 9 g of lukewarm water.

Stir gently, wait a few minutes and check the pH with strips or a calibrated meter. For a bath product, aim for the dispersion to be within a comfortable range for the skin; if the result is too far outside this, do not scale up the recipe until it has been corrected and validated.

When the test is satisfactory, package immediately in a clean, dry, tightly closed container. Protect the product from moisture, as any water ingress may activate the mixture and spoil the texture.

Before preparing large quantities, keep a small sample sealed for a few days and observe whether it clumps, loses its free-flowing quality, changes smell or reacts inside the container.