What Is Bacillus/Coix Lacryma-Jobi Ma-Yuen Seed Extract/Volcanic Ash Ferment Filtrate?
Bacillus/Coix Lacryma-Jobi Ma-Yuen Seed Extract/Volcanic Ash Ferment Filtrate is made by letting a friendly soil bacterium called Bacillus ferment two natural materials: the seeds of Job’s tears (Coix lacryma-jobi) and finely ground volcanic ash. During fermentation the Bacillus breaks down large plant and mineral particles into smaller ones and releases skin-loving molecules like amino acids, simple sugars, and trace minerals. The end result is a clear liquid filtrate packed with nutrients and mild acids that help condition the skin.
Job’s tears have been used for centuries in East Asian food and folk beauty routines because they are rich in proteins and antioxidants. Volcanic ash, often sold as “bentonite” or “clay,” is prized for its mineral content and ability to draw out oil. Modern cosmetic chemists combined these two age-old ingredients, added the Bacillus ferment step, and found the mixture gentler and more effective than the raw materials alone. This ferment first appeared in Korean skin care labs looking for fresh, natural actives in the early 2010s and has since spread to global brands focused on clean beauty.
The process starts with washing and grinding the seeds and volcanic ash, mixing them with water, then inoculating the slurry with Bacillus. The mixture ferments in warm tanks for several days. After fermentation the liquid portion is filtered off, leaving behind solids. The clear filtrate is then preserved and used as a cosmetic ingredient.
You are most likely to see Bacillus/Coix Lacryma-Jobi Ma-Yuen Seed Extract/Volcanic Ash Ferment Filtrate in hydrating toners, soothing gels, sheet masks, anti-aging serums, clay-based wash-off masks, lightweight moisturizers, and treatment essences that aim to smooth texture and boost radiance.
Bacillus/Coix Lacryma-Jobi Ma-Yuen Seed Extract/Volcanic Ash Ferment Filtrate’s Cosmetic Benefits/Uses
This ferment filtrate delivers one key benefit in skin care formulations.
Skin conditioning: The mix of amino acids, natural sugars, and minerals helps soften rough patches, support the skin’s moisture barrier, and leave the surface feeling smooth and refreshed. The gentle acids formed during fermentation can also promote a brighter look by sweeping away dull surface cells without harsh scrubbing.
Who Can Use Bacillus/Coix Lacryma-Jobi Ma-Yuen Seed Extract/Volcanic Ash Ferment Filtrate
This ferment filtrate is gentle enough for most skin types. Oily and combination skins appreciate its light mineral feel while normal and slightly dry skins benefit from the amino acids and sugars that support the moisture barrier. Very dry or highly sensitive skin may want to use it in creamier formulas instead of clay-like masks because volcanic ash could feel a bit drying when left on too long.
The ingredient is produced through a bacterial fermentation of plant seeds and mineral ash with no animal-derived substances, so it is suitable for both vegans and vegetarians.
No data indicate that the filtrate poses a specific risk to pregnant or breastfeeding women when used topically. The molecules are large enough to stay on the skin surface and do not act like retinoids or strong acids. That said, this is not medical advice and anyone who is pregnant or nursing should discuss all skincare choices with a qualified healthcare professional.
The ferment does not cause photosensitivity, so it can be used morning or night without raising the risk of sun-related irritation. Still, daily sunscreen remains important for overall skin health.
Potential Side Effects/Adverse Reactions
Reactions to topical Bacillus/Coix Lacryma-Jobi Ma-Yuen Seed Extract/Volcanic Ash Ferment Filtrate differ from person to person. The points below outline potential side effects, though most users will not experience them when the ingredient is properly formulated and used as directed.
- Mild stinging or redness in very sensitive skin, especially if the product also contains other exfoliating acids
- Temporary dryness if left on the skin too long in high-clay wash-off masks
- Allergic contact dermatitis in individuals allergic to fermented grain extracts
- Breakouts or clogged pores if the overall formulation is heavy or poorly balanced for acne-prone skin
- Over-exfoliation when layered with strong AHAs, BHAs or retinoids within the same routine
If irritation or any other unwanted reaction occurs discontinue use and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1/5
The filtrate is mostly water with small amounts of amino acids, sugars and minerals, so it contains virtually no heavy oils or waxes that tend to clog pores. Any residual particulate from the volcanic ash is removed during filtration, lowering the chance of pore blockage even further. A rating of 1 rather than 0 is given only because individual formulas may pair the ferment with richer emollients that could raise the overall comedogenicity.
This makes the ingredient generally suitable for acne-prone or breakout-prone skin.
Keep in mind that each finished product’s full ingredient list and texture matter more than a single component, so always consider the whole formula if congestion is a concern.
Summary
Bacillus/Coix Lacryma-Jobi Ma-Yuen Seed Extract/Volcanic Ash Ferment Filtrate is a gentle skin-conditioning agent that softens, hydrates and brightens thanks to its naturally fermented mix of amino acids, simple sugars and trace minerals. During fermentation the Bacillus breaks down seed proteins and volcanic minerals into smaller skin-friendly molecules that can sit on the surface and smooth roughness without irritation.
Once a niche find in K-beauty toners and essences, the ferment is now popping up in global serums, gel creams and wash-off masks, though it is still far from a household name.
Topically it is considered low-risk for most users, vegan friendly and not photosensitising. Side effects are rare and usually mild. As with any new cosmetic ingredient, patch test a small area first to confirm personal tolerance before applying more broadly.