What Is Bacillus/Monascus/Engelhardia Roxburghiana Leaf/Soybean Ferment Filtrate?
Bacillus/Monascus/Engelhardia Roxburghiana Leaf/Soybean Ferment Filtrate is a fermented botanical complex created by letting Bacillus and Monascus microorganisms work on non-GMO soybeans and the antioxidant-rich leaves of Engelhardia roxburghiana. During fermentation the microbes break down plant proteins, starches and polyphenols into smaller peptides, amino acids and skin-loving sugars while also creating new bioactive metabolites. The finished liquid is then filtered to remove solids, leaving a lightweight, water-like filtrate packed with nutrients and gentle acids that skin can readily absorb.
Fermentation has a long history in traditional foods and herbal preparations across Asia, and cosmetic chemists began exploring these techniques in the 2010s to boost the potency of familiar ingredients. Soy was an obvious candidate thanks to its natural isoflavones, while Engelhardia leaves contribute flavonoids known for calming and antioxidant effects. Combining the two under controlled fermentation conditions results in a multitasking ingredient valued for balancing oil, conditioning skin and providing antioxidant support.
The process starts with cleaned, steamed soybeans mixed with pulverized Engelhardia leaves. A starter culture containing selected strains of Bacillus and Monascus is added, and the mixture ferments at warm, humid temperatures for several days. After fermentation the mash is pressed and filtered, then the clear filtrate is stabilized and preserved for cosmetic use.
You will most often spot this filtrate in lightweight serums, oil-control toners, sheet masks, gel moisturizers, scalp essences and multi-action anti-aging formulas that aim to calm, hydrate and refine the skin surface.
Bacillus/Monascus/Engelhardia Roxburghiana Leaf/Soybean Ferment Filtrate’s Cosmetic Benefits/Uses
This fermented blend brings several useful actions to modern skincare formulas
- Anti-Sebum: Helps regulate excess oil by mildly tightening pores and balancing sebum production, making it popular in products for combination and oily skin
- Antioxidant: Supplies flavonoids and fermented isoflavones that neutralize free radicals, supporting skin’s defense against pollution and daily environmental stress
- Skin Conditioning: Delivers amino acids and sugars that boost moisture retention, leaving skin feeling smoother and more supple
- Emollient: Provides a light, breathable layer that softens the skin surface without heaviness, enhancing overall texture and comfort
Who Can Use Bacillus/Monascus/Engelhardia Roxburghiana Leaf/Soybean Ferment Filtrate
This fermented filtrate is gentle enough for normal, combination and oily skin types thanks to its oil-balancing action. Dry or sensitive skin can also benefit from its lightweight hydration as long as the overall formula contains adequate moisturizers. Extremely dry or eczema-prone skin might prefer richer emollients since the filtrate itself is water-light and not deeply occlusive.
The ingredient is derived from soybeans, Engelhardia leaves and microbial fermentation so it is suitable for vegans and vegetarians. No animal-derived substances are used at any step.
Current data do not flag any specific risks for pregnant or breastfeeding women when this filtrate is used topically, yet this is not medical advice. Anyone who is pregnant or nursing should review all skincare products with a qualified healthcare provider to be safe.
The filtrate does not increase sun sensitivity and can be worn both day and night. It pairs well with most common actives including niacinamide, hyaluronic acid and low-strength exfoliating acids. Those with a known soy allergy should check with a professional before using products that contain it.
Potential Side Effects/Adverse Reactions
Individual responses to topical Bacillus/Monascus/Engelhardia Roxburghiana Leaf/Soybean Ferment Filtrate vary. The points below outline potential, though uncommon, reactions when the ingredient is included at typical cosmetic levels. Well-formulated products are unlikely to cause these issues for most people.
- Mild stinging or redness – may occur on very reactive or freshly exfoliated skin
- Contact dermatitis – possible in individuals allergic to soy or any preservative in the finished product
- Dry patches – can arise if the filtrate’s oil-reducing effect is too strong for naturally dry skin types
- Color transfer – rare pinkish tint from Monascus pigments might temporarily stain light fabrics if the formula is not fully absorbed
If irritation or any other adverse reaction develops discontinue use and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
This filtrate is predominantly water based with only trace amounts of fermented plant lipids so it has little potential to clog pores. The few residual soy lipids are largely removed during filtration which keeps the texture light and non greasy. Because it also helps regulate excess sebum the overall likelihood of it promoting blackheads or whiteheads is very low.
Suitable for acne-prone and breakout-prone skin in most cases.
As with any formula the final comedogenicity depends on the other ingredients in the product so check the full ingredient list if you are highly sensitive.
Summary
Bacillus/Monascus/Engelhardia Roxburghiana Leaf/Soybean Ferment Filtrate delivers four main benefits: it tempers excess oil, supplies antioxidant protection, conditions the skin surface and leaves a soft emollient feel. Fermentation unlocks smaller peptides sugars and flavonoids that absorb easily which is how it carries out these multitasking roles.
While not yet a household name the ingredient is gaining traction in K-beauty style toners serums and lightweight moisturizers aimed at people who want gentle oil control without stripping the skin.
Topical use is considered low risk with only rare reports of irritation usually tied to soy allergy or other formula components. As with any new skincare product it is wise to perform a small patch test first to confirm personal tolerance.