Preservative Selection for Herbal Decoction in Water-Based Cosmetics
Question
Which preservative is suitable for a herbal decoction (Cassumunar Ginger, Turmeric, Kaffir Lime Peel, and Tinospora cordifolia) intended for use in a water-based cosmetic formulation?
- The formula includes fragrance incorporated using a
solubilizer. - The preservative must not alter the light brown color of the decoction.
- I have tried several options previously but haven't found a suitable one yet.
Answer
For a herbal decoction (fingerroot, turmeric, pomelo peel, and Tinospora cordifolia), which is highly susceptible to microbial growth due to the high content of natural nutrients, choosing a broad-spectrum preservative that does not affect the color or scent is crucial. Here are the recommended options:
1. Recommended Preservatives
- Mild Preserved Eco™ (Preservative-Free): This is the most recommended option for formulas with high natural content. It is odorless and will not alter the light brown color of your decoction.
- Usage: For herbal extracts that spoil easily, a usage rate of 2.0% is recommended for maximum protection.
- Compatibility: It can withstand heat up to 80°C and works in a pH range of 4-9. It must be blended for about 5 minutes to dissolve clearly in water.
- Mild Preserved™ COS: A broad-spectrum, water-soluble preservative that is odorless and highly effective across a wide pH range (2-8).
- Usage: 0.75-1.5%. It is a clear liquid that will maintain the visual integrity of your formula.
- Coco-Preserve™ (Preservative from Coconut Extract): If you want to maintain a "natural" theme, this coconut-derived preservative is effective against bacteria, yeast, and mold.
- Usage: 1.0-2.0% within a pH range of 4-8.
2. Fragrance Solubilization
Since your formula uses a solubilizer for fragrance, Eco Solve™ is an excellent choice. It provides high clarity and is cost-effective, ensuring that the fragrance blends perfectly into the herbal water without making it cloudy or affecting the natural brown tint.
3. Formulation Tips for Herbal Decoctions
- Cleanliness: Ensure the decoction is filtered as finely as possible to remove organic debris that can harbor bacteria.
- Timing: Add the preservative as soon as the decoction has cooled down (below 60°C for Mild Preserved Eco™ or below 45°C for Mild Preserved™ COS) to prevent early contamination.
- Testing: Because herbal decoctions vary significantly, it is highly recommended to perform a Challenge Test to ensure the preservative system is sufficient for your specific herbal blend.
These preservatives are either colorless or very light yellow, so they will not cause any color shift in your light brown herbal water.
