Shampoo Formula Review

This formula aims to create an SLS-free shampoo that makes hair soft and smooth. Let's review the formula and address your questions.

Mixing Steps

Here is a suggested mixing procedure for your formula:

1. In the main container, combine the water and Disodium EDTA. Stir until the Disodium EDTA is completely dissolved.
2. Add the Coco-Betaine, Lauryl Glucoside, BabyFoam, and Creamy Foamer to the water phase. Stir gently to avoid excessive foaming. You can warm this mixture slightly (up to 50-60°C) if needed to help the Lauryl Glucoside dissolve better, but avoid high heat.
3. In a separate container, disperse the Guar Cationic in a small amount of water or Glycerin and stir until fully hydrated (about 15 minutes). Ensure the pH is below 7.0 for proper dissolution. You may need to pre-adjust the pH of this small amount of water if necessary.
4. Add the hydrated Guar Cationic mixture to the main surfactant mixture and stir until uniformly dispersed and the desired viscosity is achieved.
5. Add Glycerin, Pro Vitamin B5, and Pure Keratin to the main mixture and stir until fully incorporated.
6. Adjust the pH of the formula to the target range of 5.5-6.5 using Citric Acid solution. Add the Citric Acid solution drop by drop, stirring and measuring the pH until it is within the desired range.
7. Finally, add the Phenoxyethanol and stir gently to combine.

Preservative Amount and Kaffir Lime Water

You are using Phenoxyethanol at 0.7%. The recommended usage rate for Phenoxyethanol is typically 0.5-1.0%. While 0.7% is within the general range, the concern raised previously about using natural ingredients like kaffir lime water is valid.

Boiling the kaffir lime water will help reduce the initial microbial load, but it may not eliminate all spores or contaminants. Natural ingredients can introduce a higher risk of microbial growth compared to using only purified water and synthetic ingredients.

Given the inclusion of boiled kaffir lime water, 0.7% Phenoxyethanol might be sufficient, but it would be highly recommended to perform a challenge test on the final product to ensure the preservative system is effective against potential microbial contamination over time. If you find microbial growth is still an issue, you might consider slightly increasing the Phenoxyethanol concentration (up to 1.0%) or using a broad-spectrum preservative blend that is more effective against a wider range of microorganisms, including fungi and yeast, which can be common contaminants in natural formulations.

Increasing Foam

To get more foam, you can increase the concentration of the surfactants in the formula. As suggested previously, increasing the amount of Creamy Foamer (Sodium Methyl Cocoyl Taurate) is a good option as it is a gentle surfactant that contributes well to foam. You could try increasing Creamy Foamer to 8-10% and see if that provides the desired foam level. Coco-Betaine also helps boost foam, so increasing its percentage slightly could also help.

Remember that the total percentage of ingredients should add up to 100% (including water). If you increase the percentage of some ingredients, you will need to decrease the percentage of water accordingly.

Overall, the formula uses gentle, sulfate-free surfactants and includes conditioning agents like Pro Vitamin B5, Pure Keratin, and Guar Cationic, which should help achieve the desired soft and smooth hair feel. The main consideration is ensuring adequate preservation, especially with the natural ingredient.