Stable Water-Based Serum Formulation: Galactomyces Ferment Filtrate and Ascorbyl Glucoside
Asked by: lee_nu322
On: December 06, 2025
Product Type:
Cosmetics
Question
I am developing a 100g personal-use cosmetic serum combining Galactomyces and Vitamin C. I require guidance on the complete formulation, including:
- Which type of Galactomyces should I select (e.g.,
Galactomyces Ferment Filtrate)? - Which type of Vitamin C should I select for optimal stability (e.g.,
Ascorbyl GlucosideorL-Ascorbic Acid)? - What are the appropriate percentages for the active ingredients?
- What base ingredients should be used?
- What is the recommended mixing method?
- What is the expected stability and shelf life of the final product?
Answer
This formulation is designed for a stable, water-based serum using the most compatible ingredients found.
Recommended Ingredients and Quantities (100g Serum)
| Ingredient | Product ID | Function | % Weight | Grams (for 100g) |
|---|---|---|---|---|
| Phase A (Water Base) | ||||
| Distilled Water | N/A | Solvent | Q.S. to 100% (approx. 61.8%) | 61.8 g |
| Glycerin (or Propanediol) | N/A | Humectant | 5.0% | 5.0 g |
| Thickener (e.g., Xanthan Gum) | N/A | Viscosity | 0.2% | 0.2 g |
| Phase B (Actives) | ||||
| Galactomyces Ferment Filtrate (aka Pitera) | 357 | Skin Conditioning | 30.0% | 30.0 g |
| Ascorbyl Glucoside (AA-2G Stabilized Vitamin C) | 265 | Vitamin C Derivative | 2.0% | 2.0 g |
| Phase C (Preservation & pH) | ||||
| Broad-Spectrum Preservative System | N/A | Preservation | 1.0% | 1.0 g |
| pH Adjuster (e.g., Citric Acid/Sodium Hydroxide) | N/A | Adjust pH | Q.S. | Q.S. |
| TOTAL | 100.0% | 100.0 g |
Ingredient Selection Rationale
- Galactomyces: We recommend Galactomyces Ferment Filtrate (aka Pitera) (ID 357) at a high concentration (30%) for maximum benefit.
- Vitamin C: We recommend Ascorbyl Glucoside (AA-2G Stabilized Vitamin C) (ID 265) at 2.0%. This derivative is water-soluble and highly stable, making it ideal for combining with the water-based Galactomyces ferment. It is stable at a skin-friendly pH of 5.0-7.0, which avoids the stability issues of L-Ascorbic Acid (which requires a very low pH of 3.0-3.5).
Mixing Method
- Prepare Phase A: In a clean beaker, disperse the thickener (e.g., Xanthan Gum) into the Glycerin (or Propanediol) to prevent clumping. Then, slowly add the Distilled Water while mixing until the thickener is fully hydrated and the base is clear and uniform.
- Add Actives (Phase B): Add the Galactomyces Ferment Filtrate and Ascorbyl Glucoside to Phase A and mix thoroughly until completely dissolved.
- Final Adjustments (Phase C): Add the broad-spectrum preservative system.
- Check pH: Measure the pH of the final serum. For Ascorbyl Glucoside, the ideal stability and efficacy range is pH 5.0 to 7.0. Adjust the pH using a few drops of Citric Acid solution (to lower pH) or Sodium Hydroxide solution (to raise pH) as needed.
- Packaging: Pour the finished serum into an opaque, air-tight bottle (preferably with a dropper).
Stability and Shelf Life
- Stability: Because this formula uses the stable derivative Ascorbyl Glucoside and is properly preserved, it is significantly more stable than formulas containing L-Ascorbic Acid.
- Shelf Life: When stored in a cool, dark place (away from direct sunlight and heat) and in an air-tight container, the serum should maintain stability for 6 to 12 months. Discard immediately if you notice any change in color (browning/yellowing), odor, or consistency.
