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 it turns out to be rather good at holding water in skin.
It is made from the grain left over after gin is distilled, and it holds water in the skin rather better than glycerin does alone.
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, and it carries the certification for genuinely upcycled materials rather than merely claiming the word.
What the fermenting does is break the barley down into smaller, more soluble pieces: free amino acids, peptides, sugars, phenolics. That is what a postbiotic is. Not live cultures, which could not survive in a jar on your shelf, but the useful residue of a fermentation that has already finished.
One thing worth knowing, because it is the sort of thing that never gets said. The material we buy is half barley ferment and half glycerin. So a portion of the glycerin on our label arrives inside this ingredient rather than being added separately. Both are declared. We mention it because you would have no way of knowing otherwise, and because 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
Two things, and the first one surprised us.
It holds water, and holds it longer
This is the interesting part. 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, sugars, and the research suggests those hold water in a way plain glycerin does not manage alone.
Emerging evidenceIt appears to calm
Its maker reports a reduction in one of the signals the skin sends when it is irritated. That is a laboratory measure rather than a result on anyone's face, and it is the honest basis for calling this a soothing ingredient rather than merely a moisturising one.
Emerging evidenceWhat 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
Marketed as Rich in antioxidants and ferulic acid
Marketed as A source of skin-nourishing minerals, including iron and copper
What we are left with is a humectant with real, if small, evidence behind it, made from something that would otherwise have been thrown away. That is a good ingredient. It does not need the antioxidants and the minerals bolted on.
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. Note that 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. Note that this is a question about your skin, not about coeliac disease, which concerns what you eat rather than what you put on it.
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. "https://doi.org/10.3390/cosmetics13010043", "url"=>"https://doi.org/10.3390/cosmetics13010043"}" rel="nofollow">→
- Chen Y, et al. Prebiotic Oligosaccharides in Skin Health: Benefits, Mechanisms, and Cosmetic Applications. Antioxidants 2025;14(6):754. "https://doi.org/10.3390/antiox14060754", "url"=>"https://doi.org/10.3390/antiox14060754"}" rel="nofollow">→
- The Upcycled Beauty Company. Gin TONIQ technical dossier: in vivo moisturisation study (n=20, corneometry) and IL-8 data. Manufacturer data, unpublished. Sponsor-generated. "https://www.upcycledbeauty.com/barley-toniq", "url"=>"https://www.upcycledbeauty.com/barley-toniq"}" rel="nofollow">→
- 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.) "https://pubmed.ncbi.nlm.nih.gov/25236235/", "url"=>"https://pubmed.ncbi.nlm.nih.gov/25236235/"}" rel="nofollow">→