When sake is pressed, the story of the rice continues. The process leaves behind sake lees: material from the fermented mash containing rice-derived proteins, amino acids and fermentation metabolites. Japan’s traditional brewing craft, recognized by UNESCO in 2024, transforms a familiar grain into several chemically different materials. Those transformations have also given skincare researchers something interesting to investigate. [1]
What changes during fermentation, and which of those changes might matter for skin?
What fermentation changes
Fermentation puts microorganisms and their enzymes to work. Research into sake-making has demonstrated how koji enzymes break rice proteins into amino acids and shorter peptides. Conditions such as acidity influence that process, helping explain why fermentation is a controlled transformation rather than simply leaving an ingredient to age. [2]
Researchers studying an Aspergillus oryzae red-rice ferment in 2024 measured sugars, proteins, peptides and polyphenols in the resulting filtrate. That preparation has its own chemical identity, distinct from rice bran, rice water or sake lees. [3]
That chemistry is part of what makes rice fermentation interesting in skincare. The more useful question is what happens when a particular preparation meets skin.
Hydration and the moisture barrier
The 2024 red-rice study examined human keratinocytes and a reconstructed three-dimensional epidermal model. Researchers observed changes in aquaporin-3, a water-and-glycerol channel, alongside filaggrin and other barrier-related markers. The reconstructed epidermis retained more water at one tested concentration, although the higher concentration did not produce the same significant result.
These findings connect a specific rice ferment with water handling and barrier biology. They also show why concentration and formulation matter alongside an ingredient’s name. [3]
Antioxidant activity and skin comfort
The same red-rice preparation reduced reactive oxygen species in UVA-exposed human dermal fibroblasts. This provides ingredient-level evidence relevant to oxidative stress. [3]
A separate 2023 study investigated water extracts of Aspergillus oryzae-fermented broken rice and brewers’ rice. Its experiments used human fibroblasts and keratinocyte–fibroblast cultures exposed to controlled ultraviolet radiation. Researchers reported reductions in inflammatory signalling molecules, including IL-1β and IL-6, in the tested cell systems. They also observed collagen-related responses after UVA exposure. [4]
This is an interesting direction for research into inflammatory signalling and skin stress responses: examining how a defined ferment interacts with stress responses and the signals cells exchange. The measurements describe cellular behaviour; they are a starting point for developing and testing skincare formulas.
What human pigmentation research measured
Some rice-fermentation research has progressed to testing topical formulas on people.
In a 2013 evaluation, 20 women applied an emulsion containing 200 ppm of a specially prepared sake extract twice daily for 14 days. Instrument readings showed a modest increase in skin lightness.
The study was a small before-and-after evaluation without a reported vehicle-control group. It offers an early finding about that particular preparation and formula, while larger controlled studies would help establish how much the extract itself contributes. [5]
The material here was a processed sake extract. Its findings should remain attached to that preparation when discussing research relevant to uneven tone.
Moisture and the appearance of fine lines
Sake lees have a separate commercial research story.
Ingredient manufacturer Technoble reports a human evaluation of a lotion containing 2% of its BIJYO HAKU sake-lees ingredient. Its technical leaflet describes improvements in dryness-related fine lines over two weeks, assessed using photographs and replicas of the eye-area skin surface.
The supplier also describes a human forearm study examining enzymes involved in generating natural moisturizing factors. These are supplier-reported findings for a named ingredient and test lotion; the public leaflet provides only part of the study protocol. [6]
For formulators, the connection between moisture and surface texture is particularly useful. It creates a practical route for exploring how rice-derived preparations might support skin that feels more comfortable and looks smoother.
Reading Blue Crystalline’s rice and fermentation ingredients
Blue Crystalline’s published ingredient list identifies three separate materials: Saccharomyces Ferment Filtrate, Hydrolyzed Rice Bran Protein and Oryza Sativa (Rice) Lees Extract. These are three distinct ingredient identities; the current production documentation still requires reconciliation before we describe them collectively as a single fermented-rice complex. Understanding those names makes the ingredient story more useful. [7]
Saccharomyces Ferment Filtrate is a filtered product of yeast fermentation. Its name identifies the fermentation organism group, but does not establish that rice was its growth substrate. [8]
Hydrolyzed Rice Bran Protein is rice-bran protein broken down through hydrolysis and used as a skin-conditioning ingredient. Hydrolysis and fermentation describe different processes. [9] [10]
Oryza Sativa (Rice) Lees Extract comes from the residue generated during rice-wine production. It is distinct from an extract of unfermented rice bran. [11]
The research helps explain why rice-derived materials and fermentation products interest formulators: they offer several avenues for studying hydration, surface condition and responses to environmental stress. In Blue Crystalline, this ingredient story sits within a broader formula of botanical extracts, peptides and hydration ingredients. The studies discussed here explain that interest; they do not measure the performance of Blue Crystalline itself.
That is the intention behind our One-Step Skincare approach: premium, multifunctional skincare that fits comfortably into everyday life, with healthy skin at its centre.
Explore Blue Crystalline Face Serum 30 ml.
