What Is Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate?
Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate is a liquid obtained after fermenting rice lees with two friendly microorganisms, Aspergillus and Saccharomyces. Rice lees are the soft solids left over after sake production, rich in proteins, amino acids, vitamins and minerals. During fermentation these microbes break down the larger rice compounds into smaller skin-loving molecules such as peptides, sugars and organic acids, then the mixture is filtered to create a clear active-packed filtrate.
The beauty industry first noticed rice ferment during observations of sake brewers who often had youthful, smooth hands. Researchers traced that glow to the nutrients released in the brewing vats, prompting cosmetic chemists to refine and bottle the filtrate for skin care. Today manufacturers cultivate Aspergillus and Saccharomyces under controlled conditions, add sterilized rice lees, allow the broth to ferment for several days then remove the microbes and solids through fine filtration. The result is a stable water-based ingredient that slips easily into modern formulas.
You will most often spot Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate in hydrating toners, lightweight essences, sheet masks, anti-aging serums, soothing gels, brightening lotions and overnight moisturizers where an extra hit of gentle nourishment is desired.
Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate’s Cosmetic Benefits/Uses
This ferment filtrate pulls double duty in skin care formulas thanks to its moisturizing and conditioning properties.
- Humectant – draws water from the environment and deeper skin layers to the surface, helping to keep skin plump, smooth and comfortable while supporting a healthy moisture barrier
- Skin Conditioning – supplies amino acids, vitamins and sugars that soften and improve overall skin texture, promoting a brighter, more even complexion and increasing the effectiveness of other actives in the formula
Who Can Use Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate
Because this ferment filtrate is water based and lightweight it generally agrees with all skin types, from oily to dry, combination and sensitive. Its humectant nature adds moisture without leaving a greasy film so even acne-prone or congested skin usually tolerates it well. There are no known skin types that must avoid it unless a person already has a confirmed sensitivity to fermented ingredients.
The ingredient is produced from rice lees and two microorganisms, neither of which are animal derived, so it is suitable for vegans and vegetarians.
No data indicate any specific risk for women who are pregnant or breastfeeding when using products containing this ferment. Still, this is not medical advice and anyone who is pregnant or nursing should clear new skincare products with their doctor just to be safe.
Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate does not make skin more reactive to sunlight and it is not known to cause photosensitivity.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate can vary from person to person. The points below outline potential reactions, but they are uncommon when the ingredient is formulated and used correctly.
- Mild redness or stinging on highly reactive skin
- Allergic contact dermatitis in individuals sensitive to yeast or fermented ingredients
- Temporary itching or tightness if applied to broken or compromised skin
- Very rare outbreak of fungal folliculitis in those prone to Malassezia related issues
If any irritation or unusual reaction occurs stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 0 / 5 – non-comedogenic
Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate is almost entirely water with small, bioavailable nutrients that are easily absorbed and do not clog pores. It contains no heavy oils or waxy residues that could trap dead skin cells or sebum, so it earns the lowest possible score on the comedogenic scale.
Suitable for acne-prone or breakout-prone skin.
Because this ferment is usually added at low concentrations and is often paired with lightweight bases such as gels, it is unlikely to interfere with other non-comedogenic ingredients in a formula.
Summary
Aspergillus/Saccharomyces/Rice Lees Ferment Filtrate works as a humectant and skin-conditioning agent. The fermentation process breaks rice lees into smaller molecules like amino acids, peptides and sugars that bind water to the skin and deliver gentle nourishment, leaving the surface soft, plump and smooth.
While not yet a household name, the ingredient has gained steady traction in K-beauty style toners, essences and sheet masks thanks to its lightweight feel and multitasking benefits.
Overall safety data show a low risk of irritation or sensitization, making it a friendly option for most skin types. As with any new skincare ingredient, a quick patch test is still the smartest way to rule out personal sensitivities before full-face use.