Indigo Biotech Innovators: Advancing Lower-Impact Dyeing Technologies
Indigo has long been central to denim production, giving jeans their iconic blue color. Conventional synthetic indigo, widely used for decades, is typically produced from petrochemical sources and plays a key role in achieving consistent quality and performance in denim manufacturing. However, its production and application can generate environmental challenges, including reliance on non-renewable resources and waste byproducts.
Biotech indigo offers an alternative approach. Positioned between plant-derived indigo and conventional synthetic dyes, these solutions are developed using less harmful ingredients and can integrate into existing processes without compromising quality. This makes them a viable option for reducing environmental impact while maintaining the standards expected in denim production.
As sustainability becomes a priority across the textile industry, biotech indigo represents an area of growing interest and investment, complementing traditional methods and expanding the range of solutions available for responsible manufacturing.
Here, executives at three indigo biotech firms—Chloris, NordicBlue and Pili—discuss where the field is headed and the development of their respective solutions.
Chloris
Dr. Sun Lei, founder and CEO
Carved in Blue: From your perspective, what is the trajectory of indigo biotech? Is the industry finally ready to adopt these solutions in a bigger way?
Sun: Indigo biotech is moving from “interesting pilots” to industrial adoption, but the shift is evidence-led, not hype-led. For years, many bio routes struggled with yield, consistency or integration into real denim supply chains. What’s changing now is clarity: Mills and brands want solutions that are drop-in compatible, predictable in performance and reliable in supply.
At Chloris, we began with Claessen Blue, a bio-based blue dye developed specifically for denim as an alternative to synthetic indigo. It is designed to run on existing indigo lines and deliver denim-native aesthetics, while improving key sustainability and process outcomes.
Over the next three years, adoption will scale fastest where three factors align: performance parity or better, in real wash and wear; a strong total-process cost logic (energy, water, chemistry and wastewater); and operational confidence built through multi-mill validation. The industry is ready, but scale will come through repeatable results.
Carved in Blue: What have traditionally been the barriers for scaling up natural dyeing for today’s mass production needs? How is your solution changing that with genetic engineering?
Sun: Scaling “natural” color has historically been limited by three practical issues: repeatability, economics and process fit. Mills and brands need stable shade, predictable behavior and reliable supply at industrial volumes. Natural sources can introduce variability, and without strong process control, it’s difficult to guarantee batch-to-batch consistency. Cost is the second barrier; if yield and productivity are not high enough, the price will not work for mass denim. The third barrier is integration; solutions must run through real dyehouse workflows and deliver consistent wash results.
Our approach with Claessen Blue is to start from a natural pigment pathway and scale it through industrial fermentation and process engineering in a closed, contained bioreactor system. We focus on strain selection and fermentation control to achieve a standardized product specification, high purity and stable quality. Rather than debating labels, we prioritize what matters operationally: consistent performance, scalable supply and compatibility with denim production.
Carved in Blue: How would you describe your Claessen Blue shade? And what colors of indigo are next in the development pipeline?
Sun: Claessen Blue is designed to be “denim-native.” It delivers a classic denim blue that supports the ring-dye and white-core aesthetic, with a controllable dark-to-light range depending on recipe and finishing. In performance terms, mills value its stability through finishing and washing, and we typically see strong light fastness (around grade 4–5) with good resistance to yellowing under UV exposure or store lighting. Importantly, the color development and wash-down effects can be achieved with less reliance on aggressive chemistry or high heat, which also helps when working with stretch denim by reducing stress on elastane.
Near-term, our roadmap is focused on expanding the blue palette for denim—more depths, undertones and wash behaviors, while keeping industrial consistency. Beyond blue, Chloris is building a broader bio-based color platform, with additional colors planned from 2026, while denim remains our anchor category.
NordicBlue
Line Holst Graves,co-CEO and chief commercial officer
Carved in Blue: From your perspective, what is the trajectory of indigo biotech? Is the industry finally ready to adopt these solutions in a bigger way?
Line: We see indigo biotech at a clear inflection point, moving from “interesting concept ” to a “viable industrial pathway” for the denim industry.
For a long time, bio-based indigo was technically promising but not ready for real production. Mills need stability, predictable quality and supply security—and those requirements are non-negotiable. What has changed is that both the technology and the market have matured.
Brands are under increasing pressure to reduce chemical impact, and mills are actively looking for solutions that lower risk without disrupting production. Today, many players are no longer asking whether alternatives are needed, but which ones actually work at scale.
And involvement from brands and mills is key. This is not a transition that can be driven by startups alone; it requires shared ambition, openness to change and long-term collaboration between technology providers, mills and brands. When that alignment is in place, indigo biotech has the potential to fundamentally reshape the industry and how denim is dyed.
Carved in Blue: You describe your indigo solution as “worry-free.” What worries exist with conventional synthetic dyes today, and how have you created an alternative without these concerns?
Line: Traditional synthetic indigo relies on hazardous chemicals and complex production processes. This creates challenges around worker safety, environmental impact, regulatory compliance and long-term risk for both brands and suppliers.
When we say “worry-free,” we mean reducing these concerns as much as possible—preferable completely removing them!
At NordicBlue, we use biotechnology to produce indigo from renewable raw materials instead of hazardous chemical synthesis. The aim is to deliver an indigo solution that is safer to produce and handle, while still behaving like the indigo the industry already knows.
Equally important, we design our solution to fit into existing dyeing setups, so mills don’t need to reinvent their processes or invest in expensive new equipment to use it—hence reducing barriers to adopt.
Carved in Blue: How scalable is bio-based indigo? If the entire denim industry switched over, would it be possible to reach a sufficient supply?
Line: Scalability is a fair and important question.
Bio-based production is already used at large scale in many industries, such as enzymes to food ingredients and pharmaceuticals. The same production principles apply to indigo.
The real question is not whether it can scale, but how quickly the industry chooses to move. Scaling bio-based indigo requires willingness from brands and mills to invest not only capital, but also time, expertise and operational resources into partnerships and trials.
If that commitment is there, scale-up can accelerate significantly. In that scenario, bio-based indigo has the potential to move beyond niche applications and become a transformative solution for the denim industry as a whole.
Pili
Jérémie Blache, CEO
Carved in Blue: From your perspective, what is the trajectory of indigo biotech? Is the industry finally adopting these solutions in a bigger way?
Jérémie: Replacing an industry that produces around 70,000 tons of petrochemical indigo every year is a major challenge, and progress has understandably taken time. Early adoption of biotech indigo solutions such as Pili’s Eco-Indigo is primarily driven by premium and luxury denim brands looking to implement best practices, reduce their environmental footprint and differentiate themselves.
But today, the broader industry context is changing. Brands are facing increasing regulatory pressure, from anti-fast-fashion legislation to the introduction of digital product passports, which require greater transparency and traceability across supply chains, making bio-based and traceable solutions increasingly relevant. Indigo biotech is finally reaching industrial and commercial maturity. The technology now delivers the same purity and performance as conventional indigo, but through a cleaner manufacturing process. As momentum builds, Pili’s Eco-Indigo is increasingly positioned to become a new standard for responsible denim dyeing.
Carved in Blue: Your Eco-Indigo is touted as high-performance. What does this mean both for production and the end product?
Jérémie: Pili’s Eco-Indigo has the exact same molecular structure as conventional indigo, which means it delivers equivalent performance in denim applications. In practical terms, it means that our biobased dye delivers identical results in terms of shade, depth, vibrancy and colorfastness. With a purity level above 90 percent, it functions as a true drop-in solution: mills do not need to modify their dyeing process or develop new recipes, and existing finishing techniques can be applied seamlessly. This has already been demonstrated through the first commercial collections launched in 2025 by brands such as Agolde and Citizens of Humanity.
Where Eco-Indigo truly differs is in how it is produced. Instead of relying on fossil fuels and hazardous chemicals, the pigment is made through fermentation. Life cycle assessment results show that this approach reduces CO2 emissions by more than 50 percent compared to conventional indigo production. For mills and brands, this means achieving the same aesthetic and performance standards consumers expect while significantly lowering the environmental impact of one of denim’s most iconic components.
Carved in Blue: You’ve reached commercial scale. Were there any bumps along the way in achieving this volume, and if so, how did you overcome them?
Jérémie: Reaching commercial scale was the result of nearly a decade of development. So yes, a road paved with bumps and success but mostly a high dose of resignation to bring our product to the market. Pili began producing its Eco-Indigo dye at industrial scale in 2024, following years of process optimization to ensure scalability, consistency and performance. In January 2025, this work culminated in the first commercial denim collection dyed with Eco-Indigo, launched by Citizens of Humanity in partnership with the Turkish mill Orta.
One of the main challenges for bio-based indigo remains cost competitiveness. Petrochemical indigo has benefited from more than 150 years of industrial optimization, resulting in very low prices. For biotech indigo, scaling production is the key lever to reducing costs.
Until now, Pili has chosen to outsource production and work with a network of partners across Europe while working toward higher volumes.
Looking ahead, Pili aims to further strengthen its value proposition by continuing to decarbonize its process and, eventually, operating its own production facility. The company is also actively involved in research projects exploring second-generation sugars derived from wood, paper, agro-industrial waste and even textiles, opening new pathways to increase sustainability while improving long-term competitiveness.