Potassium Sorbate

Potassium Sorbate – Broad-Spectrum Yeast & Mold Preservative 
INCI: Potassium Sorbate

Potassium sorbate is a water-soluble, odourless preservative widely used in handmade cosmetics to inhibit yeast, mold, and some bacteria. It is the potassium salt of sorbic acid, a naturally occurring compound, and holds GRAS status with the FDA for food and cosmetic applications. CIR (USA) assessments deem it safe in current cosmetic practices.

Key Benefits:
- Strong antifungal and anti-mold action; moderate against bacteria (especially when combined with others).
- Effective in water-based products like lotions, creams, serums, toners, shampoos, and liquid soaps.
- Pairs well with sodium benzoate or other preservatives for broader spectrum protection in natural-leaning formulas.

Usage Guidelines:
- Recommended rate: 0.1–0.5% (often 0.15–0.3% alone; 0.1–0.2% in combinations).
- Most effective at low pH: optimal below 5.5 (best at 4.0–5.0); activity drops significantly above pH 6.
- Water-soluble; dissolve in the water phase. Add during cool-down (below 60°C/140°F) to preserve efficacy.
- Adjust final product pH with citric acid or lactic acid if needed, as it can raise pH slightly.
- Include a chelator (e.g., EDTA) and use UV-protective packaging for stability.

Limitations:
- Not broad-spectrum alone—best as part of a system (e.g., with sodium benzoate for bacteria coverage).
- Not suitable for high-pH products (e.g., most bar soaps or alkaline cleansers).
- Perform microbial challenge testing on final formulations for commercial sale.