An Interview with Michelle Zhu & Tammy Hsu, PhD, of Tinctorium

Tinctorium is producing biosynthetic indigo dye to make more environmentally sustainable blue jeans (check out the awesome color transformation of their fermentation process in the time-lapse below). We spoke with their CEO, Michelle Zhu, and CSO, Tammy Hsu, PhD, to learn more about them and their company’s story.

Culture: Why is denim so bad for the environment?

Michelle: The fashion industry in general has one of the worst environmental impacts of any industry except for oil and gas. Denim in particular probably has the most pollutive production process of any of the items in our wardrobes. Not only is the indigo dye that gives denim its color produced from petroleum, formaldehyde, and hydrogen cyanide, but because indigo is not water soluble it requires additional toxic chemicals to apply the color to the cloth. 

Culture: Was it always so bad? Weren’t jeans invented by Levi Strauss in the 1800’s? 

Tammy: Indigo dye for denim has mostly been synthetic; the production process was discovered in the late 19th century and expanded with the popularity of jeans. As denim became more fashionable and trends evolved over time the dyeing process became more and more pollutive, going from coloring just raw denim to sand blasting and using different finishing techniques. 

"Always know who you’re trying to sell to, and optimize your bioprocess with their price point in mind." 

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Culture: How widespread is this problem? Are some denim manufacturers better than others?

Michelle: We are seeing a few denim brands trying to be more sustainable. But there has historically been a risk aversion by brands to position themselves this way and invest too much, particularly because most brands don’t own their supply chain. Many people say they care about sustainability but don’t necessarily pay more for it, so brands have been hesitant to put that front and center in their messaging about what makes them special. This is changing rapidly, however, and will continue to change over time as sustainability becomes more top of mind for consumers.

Tammy: Even for denim manufacturers who are trying to be more sustainable, they’re limited in their options. There are some emerging technologies around saving water or finding alternative fibers, but no one has tackled the environmental problem of chemical indigo dye because there is no good alternative. This is in spite of the fact that the whole industry knows how polluting dyes can be. Some have used plant derived dyes, but the water and land required to produce a sufficient quantity would itself be unsustainable. 

Culture: So where did the idea come from to make indigo dye biosynthetically? 

Tammy: The process for creating our indigo dye was actually my PhD thesis; I have been working on it for the last six years while studying bioengineering at UC Berkeley. The initial impetus for developing this biosynthetic process wasn’t for fashion; others in John Dueber’s lab had been looking to develop a cellular assay where removal of a glucosyl group resulted in a color change. The Japanese indigo plant, P. tinctorium (which is where our name comes from), has a tightly controlled color changing process regulated by glucosylation, so they worked to identify the genes controlling this process and clone them into E. coli. We then realized that this process from the plant could have major implications for the textile dye industry.

When I joined the lab there was one key enzyme that had not been identified, so I focused on it as a jumping off point for my thesis. 

Culture: How did you two meet each other and decide to start the company? 

Tammy: I hadn’t always had an interest in starting a company, but when my project was successful I realized it had the opportunity to be both commercially viable and environmentally beneficial. Michelle’s fiance is a bioengineer in the same lab at Berkeley and, when I mentioned I was looking for a co-founder with more of a business background, he connected us. 

Michelle: It was so serendipitous because I also had been thinking about doing something entrepreneurial, and my background in management consulting and business operations complemented Tammy’s skills. My family also works in the denim industry and I grew up learning all about it, so it all felt like a great fit. 

Culture: What is Tinctorium’s business model? Are you launching your own fashion line, or selling the biosynthetic indigo dye to existing denim manufacturers? 

Michelle: Our long term vision is to take over the indigo market: there should be no other way to make indigo except via our biosynthetic process. Formaldehyde simply shouldn’t be in our jeans. Not only is our indigo dye more sustainably produced, but because it also reduces water pollution in the dyeing process, it impacts multiple elements of the denim supply chain. 

In the short term, however, while our production costs are higher, we’ll sell to a customer base willing to pay a premium for sustainability. We’ll start by making our own denim line so we can control the messaging and educate the public on the harmful effects of standard denim production. We’ll also look for partner brands in the high-end apparel category. 

As our costs come down from improving and expanding our indigo production, we’ll grow our B2B partnerships by making co-branded lines with more mass-market brands. 

Culture: It looks like you've recently brought on some amazing advisors. How did that come about and how has it been so far? 

MIchelle: The guys at Bolt Threads are an incredible resource for emerging companies at this intersection of fashion and biotech. Even before David Breslauer, CSO of Bolt, was an official advisor he had been so generous with his time in terms of providing us perspective and making introductions on our behalf. It was David who introduced us to a sustainable apparel maker who then introduced us to a denim developer which led to us meeting Adriano Goldschmied, otherwise known as “the Godfather of Denim.”

We were thrilled to have Adriano’s support. He basically created the premium denim category and knows everyone in the industry.  The denim industry can be notoriously a closed network but he was so open to helping because he really wants to bring more sustainable technologies to market. 

Culture: How was your experience with IndieBio? How has it helped you? 

Michelle: IndieBio has been a great experience for us as first-time founders who wanted hands-on support. They provide constant access to mentorship beyond just regular programming. It also provides a really close community-- our cohort of 11 companies is together almost every day in the lab sharing stories and learning from each other. 

Tammy: IndieBio really pushes us to move fast and iterate on our ideas quickly. It’s challenging to develop our company at this pace, but it helps us prioritize progress over perfection. 

Culture: Any final words of advice for other synthetic biology companies just starting out now? 

Tammy: Always know who you’re trying to sell to, and optimize your bioprocess with their price point in mind.

Michelle: Echoing Tammy’s point, it is so important to do market validation and have a business model early on. We’ve been lucky to have been really embraced so far by the industry we’re in.