PostbioticUpcycled from ginIn every formula

Saccharomyces/Barley Seed Ferment Filtrate

Hordeum vulgare, fermented by Saccharomyces · INCI Saccharomyces/Barley Seed Ferment Filtrate

Barley is malted and fermented to make the alcohol that becomes gin. The gin is distilled off, and what is left behind is a great deal of spent grain. This ingredient is made from that. It is the part of the process nobody wanted, and its maker has found it rather good at holding water in skin.

It is made from the grain left over after gin is distilled. In its maker's study, it held water in the skin better than glycerin alone.

Barley, fermented for gin, then upcycled into the postbiotic in every formula.

What it is

Spring barley is grown in East Anglia, malted, and fermented with Saccharomyces, brewer's yeast. The alcohol is distilled off to make gin. The fermented grain that remains, which would otherwise be waste, is captured fresh and filtered, and that filtrate is what reaches our formulas. It is made in the UK. It is certified upcycled.

What the fermenting does is break the barley down into smaller, more soluble pieces: free amino acids, peptides, sugars, phenolics. That residue of a finished fermentation is what makes it a postbiotic, the term cosmetic science uses for ferment filtrates like this one. It contains no live cultures; none could survive in a preserved cosmetic. Its maker makes no claim about the skin microbiome.

The material we buy is half barley ferment and half glycerin, so a portion of the glycerin on our label arrives inside this ingredient. Both are declared. The two work together: the glycerin pulls water in, and the ferment seems to help hold on to it.

What it does in our formulas

It is a humectant, and its maker reports a laboratory hint of soothing.

It holds water, and holds it longer

In its maker's study, twenty people had it measured against a glycerin solution and against nothing at all. It held roughly three times more moisture in the skin than the glycerin did, and it was still working at eight hours, when the glycerin had stopped. Fermenting barley breaks it into smaller pieces, amino acids, peptides and sugars, and its maker attributes the result to those smaller pieces.

Emerging evidence

A laboratory hint of soothing

Its maker reports a reduction in one of the signals the skin sends when it is irritated. That is the maker's laboratory finding, not a result on skin.

Emerging evidence

What the research does not show

The evidence for this ingredient is better than we expected. The marketing around it still runs ahead in a few places.

Marketed as A probiotic, or living cultures for your skin

No live organism survives in a preserved cosmetic. A postbiotic is what is left once fermentation is over: the ferment is filtered, the yeast removed, and what remains is the useful debris of fermentation.

Marketed as Rich in antioxidants and ferulic acid

Fermented grain does contain phenolic acids, and the papers cited for this are about beer polyphenols and about ferulic acid in general. They are not about this ingredient. What is in the grain is not the same as what is in the bottle, or what reaches your skin, so we claim the hydration, which was measured, and not the antioxidants, which were inferred.

Marketed as A source of skin-nourishing minerals, including iron and copper

We had to smile at this one. Iron and copper are exactly the metals that make oils turn rancid, which is why there is an ingredient in our formulas whose job is to mop them up. In a cream containing plant oils they are no benefit. They are present in traces, doing nothing much.

On the label and in the range

The barley ferment appears in every one of our formulations, in the middle of the ingredient list. It reads by its INCI name, Saccharomyces/Barley Seed Ferment Filtrate, which is a mouthful and means barley fermented by yeast and then filtered. The hash beside it marks it as upcycled. It arrives with an equal weight of glycerin, so part of the glycerin declared further up the list comes in with this ingredient. The exact percentages are published on each product page.

Is it suitable for me?

The filtrate contains no live organisms, suits a vegan routine, and carries no restrictions under UK or EU cosmetic law. It is certified upcycled, conforms to the COSMOS organic standard, is certified under NaTrue, and is palm-free. It is derived from barley, a cereal, so if you are sensitive to cereals a patch test first is sensible.

Vegan-friendlyWell tolerated

The filtrate is derived from barley, a cereal. It contains no live organisms, but if you react easily, or you are sensitive to cereals, a patch test first is sensible.

The research behind this page

We review the published literature. We do not conduct the studies below.

Yu J, Ma X, Wang X, et al. The Skin Microbiome Revolution: The Science and Challenges of Prebiotics, Probiotics, and Postbiotics in Skincare. Cosmetics 2026;13(1):43. (Background on postbiotics; not a study of this ingredient.) →
The Upcycled Beauty Company. Gin TONIQ technical dossier: in vivo moisturisation study (n=20, corneometry) and IL-8 data. Manufacturer data, unpublished. Sponsor-generated. →
Quifer-Rada P, et al. A comprehensive characterisation of beer polyphenols by high resolution mass spectrometry. Food Chem 2015. (Background on grain phenolics; not a study of this ingredient.) →

Found in every Biotaderm formulation Shop the range