Understanding Serum Separation

It's understandable that your serum separated after adding the preservative, Phenoxyethanol. Based on your formula and the helpful replies you received, the issue likely stems from the emulsification process involving Warp Cream Maker and Cyclomethicone.

Why Separation Occurred

Your formula uses Warp Cream Maker, which is a water-in-oil/silicone emulsifier designed to create an emulsion between a water phase (ingredients 1-11) and an oil/silicone phase (Cyclomethicone and Warp Cream Maker itself). Creating a stable emulsion requires sufficient energy to properly disperse one phase within the other.

• Emulsifier Activation: Emulsifiers like Warp Cream Maker need adequate mechanical force (mixing) to hydrate and orient themselves correctly at the interface between the water and oil/silicone phases. This forms a stable barrier preventing the phases from separating.
• Insufficient Energy: If the mixing in step B (combining A and B) wasn't vigorous or prolonged enough, the emulsion might have been weak or incomplete. The replies suggesting using a mixer and heat point to this, as both provide the energy needed for proper emulsification.
• Water Phase Load: While not the sole cause, a high percentage of the water phase relative to the emulsifier and oil/silicone phase can make creating a stable emulsion more challenging.
• Preservative as a Trigger: Phenoxyethanol itself doesn't typically cause separation in a well-formed, stable emulsion. However, if the emulsion is already weak or unstable, adding another ingredient, especially one that can slightly alter the properties of the water phase, can sometimes disrupt the delicate balance and trigger separation over time.

Why Mixing and Heat Helped

The suggestions to use a mixer and gentle heat were effective because they provided the necessary energy to help the Warp Cream Maker properly emulsify the formula. Mixing increases shear force, breaking down droplets and allowing the emulsifier to form a stable network. Gentle heat can reduce the viscosity of the phases, making them easier to blend and helping the emulsifier function more efficiently.

Adding Silicone Gel Base

You asked about adding silicone gel base to fix the issue. While silicone gel base contains Cyclomethicone and thickeners, adding it to a separated emulsion is generally not the correct way to fix the problem. It won't re-emulsify the separated phases. The solution lies in re-processing the existing mixture to properly emulsify it, which you achieved with additional mixing and heat.

Tips for Using Warp Cream Maker

• Ensure you are using a mixer with sufficient speed (at least 1000 rpm is often recommended for this type of emulsifier).
• Mix the oil/silicone phase (Cyclomethicone and Warp Cream Maker) thoroughly before gradually adding the water phase.
• Add the water phase slowly, with continuous mixing, allowing each addition to be fully incorporated before adding more.
• Gentle warming of the oil/silicone phase (as suggested by others) can help the Warp Cream Maker disperse better before adding the water phase, especially if your formula contains ingredients that need melting.
• Consider adding 1% Magnesium Sulfate to the water phase before combining with the oil phase, as recommended in the description for Warp Cream Maker, to improve stability.

It's great that the texture improved with the mixing and heat! This indicates the core issue was achieving proper emulsification.