What Is Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate?
Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate is a skincare ingredient created when the peel of Citrus unshiu, a small seedless mandarin native to East Asia, is fermented with Bacillus bacteria. The fermentation process breaks down the peel’s natural sugars, flavonoids and essential oils into smaller molecules that skin can use more easily. What remains after the fermentation broth is filtered is a clear fluid rich in skin friendly metabolites, amino acids and mild fruit acids.
Citrus peels have been part of traditional beauty rituals in Japan and Korea for centuries, valued for their gentle brightening and refreshing properties. Modern cosmetic science paired this heritage ingredient with Bacillus fermentation in the early 2000s to boost its efficacy and stability, paving the way for today’s filtrate to enter commercial formulas.
To make the ingredient, manufacturers start with dried or freshly grated Citrus unshiu peel, steep it in a nutrient solution then introduce a selected strain of Bacillus. The mixture ferments under controlled temperature and pH for several days. After fermentation, the liquid is filtered to remove bacterial cells and peel residues, yielding a lightweight filtrate ready for use.
You will most often find Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate in hydrating toners, soothing sheet masks, lightweight moisturizers, anti aging serums, blemish control gels, eye creams and after sun lotions where it adds a touch of natural freshness while supporting skin comfort.
Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate’s Cosmetic Benefits/Uses
This multitasking ferment brings more than one perk to a formula
- Antimicrobial – helps curb the growth of unwanted surface bacteria which can reduce the risk of spoilage in the bottle and support clearer looking skin once applied
- Emollient – supplies light conditioning molecules that soften rough patches, improve skin suppleness and leave a smooth, non greasy finish
Who Can Use Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate
This gentle ferment suits most skin types, from oily and combination to normal and dry. Its light emollient feel makes it pleasant for those prone to clogged pores while its soothing properties can bring comfort to dry or slightly sensitive complexions. Very reactive or highly sensitized skin should still introduce it slowly because any new ingredient can cause an unexpected tingle.
The filtrate is made from plant peel and a food grade Bacillus culture, with no animal derived components, so it is appropriate for vegans and vegetarians.
No data point to problems for women who are pregnant or breastfeeding, yet research in these groups is always limited. This information is not medical advice and anyone who is expecting or nursing should show the product label to a doctor before use just to be safe.
The ingredient itself is not known to increase photosensitivity. Standard daytime sun protection is still advised for general skin health.
Potential Side Effects/Adverse Reactions
Responses to Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate vary from person to person. The points below list potential but unlikely effects when the ingredient is used correctly in a finished product.
- Mild stinging or tingling during the first few uses
- Temporary redness or warmth in very sensitive skin
- Allergic contact dermatitis in individuals allergic to citrus components
- Rare breakout flare if the formula contains other pore clogging ingredients
- Eye irritation if the product is accidentally rubbed into the eyes
If you notice any of these reactions stop using the product and seek advice from a qualified healthcare professional.
Comedogenic Rating
Rating: 1/5
Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate is mostly water based and contains only trace amounts of lipids, so it is unlikely to clog pores. Its molecules are small, lightweight and readily absorbed, which keeps residue on the skin to a minimum.
Suitable for acne-prone or breakout-prone skin in most cases.
Keep in mind the overall formula matters. If this ferment is paired with rich butters or heavy oils the product’s final pore-clogging potential can rise.
Summary
Bacillus/Citrus Unshiu Peel Extract Ferment Filtrate acts as an antimicrobial and a light emollient. Fermentation produces skin friendly peptides, mild fruit acids and humectant sugars that help inhibit surface microbes while smoothing rough texture and boosting softness.
The ferment is still a niche ingredient, most common in Korean and Japanese inspired formulas yet slowly appearing in global toners, serums and masks.
Current data show it to be low risk with few reported reactions. As with any new skincare ingredient it is wise to patch test first to make sure your skin agrees with it.