Ingredient review

Aureobasidium Pullulans Ferment

INCI: AUREOBASIDIUM PULLULANS FERMENT

A gentle, biotech-derived humectant that helps hydrate and soothe the skin, with some antioxidant potential.

beautyskincarehumectant

In plain English

This ingredient is made by fermenting a type of black yeast (Aureobasidium pullulans) in a lab. The fermentation process creates a mix of beneficial compounds, including polysaccharides (natural sugars) and amino acids, that help attract and hold moisture in the skin. It's like a gentle, watery sponge for your skin, and it may also help calm irritation. You'll often find it in serums and moisturizers aimed at dry or sensitive skin.

Quick decision guide

Useful, but context matters

Aureobasidium Pullulans Ferment is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Aureobasidium Pullulans Ferment.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

Aureobasidium pullulans ferment is the result of fermenting the black yeast Aureobasidium pullulans. This yeast is found naturally on plant leaves and in soil. The fermentation process breaks down the yeast cells, producing a liquid rich in polysaccharides (like pullulan), beta-glucans, and other skin-friendly compounds. It is a biotech ingredient, meaning it's produced in a controlled lab environment for consistency and purity.

How it works

In a cosmetic product, Aureobasidium pullulans ferment works primarily as a humectant. The polysaccharides it contains form a thin, invisible film on the skin's surface that helps trap moisture and reduce water loss (transepidermal water loss, or TEWL). Some research suggests the beta-glucans in the ferment can also help calm inflammation and support the skin's natural barrier function. It does not exfoliate or actively change skin cell turnover.

Pros

Excellent humectant

Pulls moisture into the skin and helps keep it there, making it great for dry or dehydrated skin types.

Very gentle

Unlikely to cause irritation or clog pores, so it's suitable for sensitive and acne-prone skin alike.

Cons and cautions

Texture can be tacky

At higher concentrations, products may feel slightly sticky or tacky on the skin, which some people dislike.

Limited standalone research

Most evidence comes from studies on the whole ferment or its components (like pullulan), not the ferment itself in finished skincare.

Best for

  • People with dry or dehydrated skin looking for extra hydration
  • Those with sensitive or easily irritated skin who want a gentle humectant

Use caution if

  • Individuals with a known allergy to fermented ingredients or yeast (rare)

Usage tips

Apply products containing this ferment to slightly damp skin to maximize its moisture-binding effect.
Layer it under a richer moisturizer or occlusive (like a cream with shea butter) to lock in the hydration.

Safety summary

Aureobasidium pullulans ferment is considered safe for topical use in cosmetics. It has a low irritation and comedogenic risk. Allergic reactions are rare but possible in individuals sensitive to fermented ingredients. As with any new product, a patch test is recommended.

Research notes

Research on Aureobasidium pullulans ferment is moderate. Studies on its key component, pullulan, show it forms a flexible film that reduces water loss. Beta-glucans from the same yeast have demonstrated anti-inflammatory and antioxidant activity in lab and some human studies. However, direct clinical trials on the ferment itself in finished skincare products are limited.

Common label clues

Typical concentration
0.5% to 5% in leave-on products
Regulatory status
Generally recognized as safe for use in cosmetics by major regulatory bodies (e.g., FDA, EU CosIng). No specific restrictions.
Common uses
Serums, Moisturizers, Sheet masks, Eye creams
Environmental note
Produced via controlled fermentation, which is a relatively low-impact biotech process compared to extracting ingredients from wild plants.

Good to know

  • This ingredient is often listed as 'Aureobasidium Pullulans Ferment' on labels, but it may also appear as 'Pullulan Ferment' or 'Black Yeast Ferment'.
  • It is produced via fermentation, which is a natural process, but the final ingredient is lab-made for consistency.

Common questions

What is Aureobasidium Pullulans Ferment in beauty products?

This ingredient is made by fermenting a type of black yeast (Aureobasidium pullulans) in a lab. The fermentation process creates a mix of beneficial compounds, including polysaccharides (natural sugars) and amino acids, that help attract and hold moisture in the skin. It's like a gentle, watery sponge for your skin, and it may also help calm irritation. You'll often find it in serums and moisturizers aimed at dry or sensitive skin.

What does Aureobasidium Pullulans Ferment do in a beauty product?

In a cosmetic product, Aureobasidium pullulans ferment works primarily as a humectant. The polysaccharides it contains form a thin, invisible film on the skin's surface that helps trap moisture and reduce water loss (transepidermal water loss, or TEWL). Some research suggests the beta-glucans in the ferment can also help calm inflammation and support the skin's natural barrier function. It does not exfoliate or actively change skin cell turnover.

Is Aureobasidium Pullulans Ferment safe for most people?

Aureobasidium pullulans ferment is considered safe for topical use in cosmetics. It has a low irritation and comedogenic risk. Allergic reactions are rare but possible in individuals sensitive to fermented ingredients. As with any new product, a patch test is recommended.

Who should be careful with Aureobasidium Pullulans Ferment?

Individuals with a known allergy to fermented ingredients or yeast (rare)

Research sources

CosIng - European Commission databaseOpenPubMed - Pullulan film propertiesOpenPubMed - Beta-glucan skin benefitsOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.