The waste from brewing and pharmaceuticals may soon weave into wardrobes. Scientists at Penn State in the US have developed a fibre spun from leftover yeast, offering a sustainable, biodegradable alternative to wool and synthetic fibres. Pilot production in Germany achieved full-scale operational continuity, producing pilot-scale quantities of material and demonstrating that protein-based fibres can scale without the heavy environmental toll of conventional textiles.
- The pilot trials ran continuously, producing pilot-scale quantities of fibre and demonstrating stable spinning performance using existing equipment.
- Modelling estimated production costs near six dollars per kilogram, comparable with wool, while requiring substantially less land and water across the assessed life-cycle stages.
- The findings published in Proceedings of the National Academy of Sciences underpins the pilot and modelling results. The lead author was Melik Demirel, Pearce Professor of Engineering and Huck Chair in Biomimetic Materials at Penn State. The team included Benjamin Allen, Balijit Ghotra, Birgit Kosan, Philipp Köhler, Marcus Krieg, Christoph Kindler, and Michael Sturm.
THE STUDY: The researchers demonstrated a pilot process that transforms fermentation by-products from brewing and pharmaceutical industries into a spinnable, biodegradable protein fibre, conducted in Germany. Continuous and batch trials exceeded 100 hours, yielding over 1,000 pounds of material. Cost and lifecycle assessments suggested competitiveness with wool at roughly $6 per kilogram while cutting land, water and emission footprints significantly.
- Fermentation waste was dissolved in a lyocell type solvent with 99.6 per cent recovery, producing uniform, biodegradable fibres suitable for yarn and fabric manufacturing.
- Pilot production validated mechanical stability and consistent throughput in continuous operation beyond 100 hours across multiple runs without notable process deviations.
- Economic modelling indicated costs near $6 per kg, positioning the fibre competitively with wool at commercial-scale assumptions used in the analysis.
- Lifecycle modelling indicates significantly lower water and land use and near-zero greenhouse-gas emissions compared with conventional fibres.
- Sonachic, an online brand formed by Tandem Repeat, makes this a reality. The project was supported by the BioMADE and Defense Industrial Base Consortium through a grant from the US Department of Defense.
OBSERVED OUTCOMES: Solvent recovery was near-complete. Continuous and batch operations both achieved stable throughput without process degradation, validating the process beyond laboratory demonstration. Solvent regeneration efficiency reduced overall emissions and waste-water output.
- Economic modelling aligned pilot results with commercial scalability benchmarks, indicating cost-competitive potential with natural fibres such as wool.
INDUSTRY SIGNIFICANCE: The research positions fermentation waste as a new raw-material stream for textiles, reducing dependence on petroleum-based synthetics and resource-heavy natural fibres. By converting industrial by-products into high-performance, biodegradable yarns, the process links waste reduction with sustainable manufacturing, promising circular benefits across brewing, pharmaceutical, and apparel sectors without requiring new agricultural inputs or synthetic polymers.
- It demonstrates a closed-loop textile route using existing industrial waste instead of virgin feedstocks, aligning fibre production with circular-economy objectives.
- The study also offers major resource savings by cutting agricultural land and water use and lowering emissions, freeing capacity for food crops in regions facing hunger.
- It opens new economic value chains for breweries and pharmaceutical plants by repurposing residues into high-value textile fibre sold to apparel manufacturers.
NUANCED TAKE: The study acknowledges that industrial adoption remains a challenge. Pilot operations were limited to hundreds of kilograms, well below commercial output targets. Variables such as yeast strain, feedstock consistency, and solvent-recovery cycles still need validation under full-scale conditions. Commercial success will depend on stabilising input variability and aligning process costs with large-volume textile manufacturing standards.
- Production volumes achieved remain pilot level and must be scaled significantly to demonstrate consistent industrial throughput across extended campaigns and facilities.
- Feedstock quality variations between yeast sources could affect uniformity and fibre characteristics, requiring specification controls and pre-processing to maintain consistent spinning performance.
- Further optimisation of recovery and purification steps is required to ensure cost efficiency at mass scale without sacrificing fibre properties or environmental benefits.
WHAT’S NEXT: The Penn State team plans to advance towards commercial-scale trials, optimising solvent recovery and exploring licensing with industry partners. Future work will examine mechanical spinning performance, fabric finishing, and lifecycle durability under varied conditions. The researchers expect findings from ongoing tests to inform industrial adoption, certification pathways, and wider application of protein-based fibres in sustainable textile production.
- The next phase aims to replicate pilot success at full commercial scale with broader yeast-source validation and detailed cost tracking across extended operations.
- Collaboration discussions are under way for licensing the technology to industrial fibre producers, including agreements to support equipment integration and factory trials.
- Further analysis will assess long-term biodegradability and performance in woven and knitted fabrics across laundering cycles and typical wear conditions.
WHAT THEY SAID
Just as hunter-gatherers domesticated sheep for wool 11,000 years ago, we’re domesticating yeast for a fiber that could shift the agricultural lens to focus far more resources to food crops. […] By looking to microorganisms instead of animals or plants, we can imagine a textile future that produces far less waste and uses resources far more responsibly.
— Melik Demirel
Pearce Professor of Engineering and Huck Chair in Biomimetic Materials
Penn State
