Summary
The carpentry firm Koster AG Holzwelten and Empa have developed a standardized process for producing marmorwood and are bringing it to market under the name Myrai. This special wood is created through controlled colonization by an ascomycete fungus that deposits natural melanin pigment and produces characteristic black lines. The Innosuisse project transforms a former accidental discovery into a scalable, high-tech production process and opens up new value creation for native hardwoods that have previously been mostly burned as fuel.
People
- Francis Schwarze (Empa fungal expert)
- Jakob Koster (CEO and founder, Koster AG Holzwelten)
- Lewis Douls (Chemist, scale-up)
Topics
- Biotechnology and wood refinement
- Sustainable material innovation
- SME research cooperation
- Circular economy and CO₂ storage
Clarus Lead
What was once a rare forest discovery is now high-tech: an ascomycete fungus deliberately draws black melanin lines into the wood. The cooperation between the St. Gallen family business Koster AG Holzwelten and Empa has developed a reproducible process that transforms native hardwoods such as maple, beech, and ash into high-quality decorative materials. For decision-makers: the project demonstrates how SMEs can scale complex biotechnology solutions through research partnerships and thereby utilize local resources instead of exotic imported woods. Market entry under the Myrai brand opens new business fields for previously underutilized wood and reduces CO₂ emissions by avoiding combustion.
Detailed Summary
The innovation began by accident: Jakob Koster discovered black lines on a piece of wood from his carpentry workshop and showed it to Empa researcher Francis Schwarze. He immediately recognized that an ascomycete fungus – known as a pest on hardwood trees – had left the pattern. The potential was obvious: instead of storing tree trunks in the forest for months and hoping for the right fungal infestation, the marbled wood should be produced deliberately.
The resulting Innosuisse project established a standardized process. Boards are brought to the correct moisture content in a vacuum chamber, sterilized, and inoculated with the fungus. In climate-controlled chambers, the fungus decorates the wood over several weeks with its characteristic lines. After technical drying, the fungus dies – the special feature: it only breaks down weakly lignified cell wall areas, which means the wood retains its high bending stiffness. The end product is suitable for furniture, interior finishing, musical instruments, and jewelry.
Scale-up was a significant challenge. Chemist Lewis Douls, who moved from Empa to Koster, had to ensure sterility under laboratory conditions – a complex task since fungal spores are everywhere. Investment in biotechnology equipment (autoclaves, vacuum chambers) was substantial. The company showed ingenuity: climate chambers were taken over from a former edible mushroom cultivator, laboratory equipment was adapted from ETH Zurich. Douls optimized process steps so that expensive large-scale autoclaving became unnecessary. The resulting production facility is now better equipped than the original Empa laboratory.
The market readiness of Myrai has significant sustainability implications: native hardwoods, which in Switzerland are predominantly burned as fuel, now receive higher-value applications. Wood is a CO₂ sink – as long as it is not burned. Locally produced refinement replaces expensive imported woods and conserves resources. The next phase is economic scaling; initial customer inquiries are already in hand.
Key Messages
- Standardization of accidental discoveries: A natural process (fungal infestation) was transformed into a reproducible, high-tech procedure.
- SME-research synergy: Small and medium-sized enterprises can successfully scale complex biotechnology innovations through cooperation with research institutions.
- Resource efficiency: Native hardwoods, previously fuel, are refined into high-quality decorative materials – avoiding CO₂ emissions and import dependency.
- Sterility challenge: Fungal cultivation requires extreme control conditions; optimizations (e.g., eliminating large-scale autoclaving) are critical for economic viability.
Critical Questions
Data Quality & Reproducibility: How consistent are the melanin patterns across multiple production batches? What error rates result from contamination or fungal variability, and how are these factored into cost calculations?
Scaling Risks: The production facility is new; are there long-term data on the stability of climate chambers and throughput? How quickly can capacity be increased if demand grows unexpectedly?
Market Validation: The press release mentions "inquiries," but concrete orders or market size are not mentioned. How realistic is the amortization of investments, and what competition exists (e.g., other fungal wood suppliers, imports)?
Conflicts of Interest: To what extent does Empa benefit from licensing fees or publications? Are there dependencies that could jeopardize research independence?
Ecological Side Effects: What control measures prevent fungal spores from the production facilities from escaping into the environment? Could the ascomycete fungus, if it escapes, become a problem for forests?
Economic Viability vs. Sustainability: Is marmorwood price-competitive with exotic woods and industrially manufactured decorative materials, or does it remain a niche luxury product?
Raw Material Scalability: Are native hardwood stocks sufficient for significant production increases, or is there competition with other uses (energy wood, construction wood)?
Source Directory
Primary Source: Press Release: From the Laboratory to Market: Signed by Fungus – https://www.news.admin.ch/de/newnsb/ChTm2cBJtg-MrAZlJWkQX
Contact Information:
- Prof. Dr. Francis W.M.R. Schwarze, Empa, Cellulose & Wood Materials, Tel. +41 58 765 7247, [email protected]
- Jakob Koster, Koster AG Holzwelten, Tel. +41 79 629 30 45, [email protected]
Verification Status: ✓ February 12, 2026
This text was created with the support of an AI model. Editorial responsibility: clarus.news | Fact-checking: February 12, 2026