Citizens of Humanity ditches synthetic denim dyes for an indigo that’s brewed like beer

In 1897, Badische Anilin- und Sodafabrik (now known as BASF), launched the first commercially viable synthetic indigo, dramatically disrupting a centuries-old natural dye industry centered around indigo plantations in India and the Americas. Within two decades, synthetic indigo had captured 90% of the global market, transforming how jeans and other blue textiles get their color. The shift was driven by the emerging petroleum industry and advances in organic chemistry, but it came with hidden costs. While synthetic indigo offers consistency and lower prices, it introduced dependencies on fossil fuels and toxic chemicals like aniline.

Now, there's an affordable opportunity to switch back to natural. Premium denim brand Citizens of Humanity is partnering with French biotech firm Pili to introduce jeans colored with bacteria-produced indigo dye. The collaboration, launching with a Spring 2025 collection, reimagines one of fashion's most resource-intensive processes by replacing petroleum-based dyes with colors created through fermentation — similar to brewing beer. Pili's innovation could slash carbon emissions by up to 50% compared to conventional denim dyeing while maintaining the rich, lasting blue that denim wearers expect.

Pili's process feeds sugar to specially engineered microorganisms that produce pure indigo dye, eliminating the need for chemicals like aniline that endanger workers and waterways in traditional denim production. By integrating seamlessly with existing dyeing equipment, this alternative makes sustainability accessible without requiring significant changes to manufacturing processes. The move to bio-based indigo represents more than just a technical achievement — it signals a broader transformation in how everyday products can evolve to lower their negative impact on planet and people.