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Denim and beyond: Huue’s pursuit of ‘clean color’ dyes

This biotechnology company is disrupting the dye industry.

Collage of denim in different shapes and sizes with an orange background

 Image by Sophia Davirro/GreenBiz

Biotechnology company Huue (pronounced hue) is on a mission to mimic and replicate nature’s rainbow without the use of toxic chemicals.

"We wanted a name that would allow us to redefine how we think about color while being very simple," Huue CEO Michelle Zhu told GreenBiz. "We thought Huue would put us on the path to being synonymous with color and reflect that we’re making color as nature intended."

The idea for Huue, which creates non-toxic alternatives to synthetic dye for textiles, started in a lab on the University of California, Berkeley campus, where Tammy Hsu, chief scientific officer at the company, earned her Ph.D. in bioengineering.

Huue founders — two people — pose on stairs

Huue Founders Michelle Zhu (L) and Tammy Hsu (R). Image courtesy of Huue.

This was also where friendship started. Zhu’s partner is also a bioengineer and worked in the same lab at Hsu. Because of that connection, the CEO and CSO had become friends before launching their business.

The beginning of Huue

When Hsu was in graduate school, one of the first things she did was look into how plants made indigo and find the enzyme necessary to create the color. Then she engineered microbes to produce the enzyme and make indigo themselves. This process was the foundation for the way Huue operates now.

In early 2019, Hsu recognized the interest and demand for this kind of technology from fashion brands. That’s when Hsu, with her scientific expertise, and Zhu, with her business operations and strategy background, joined forces to found Huue.

Zhu grew up in a family that was in the business of textiles and apparel. Her parents started their apparel brand focused on urban streetwear segments in the late 1990s and over time expanded into all clothing categories for all genders through numerous brands.

"I would visit some of the garment manufacturing facilities on summer trips to China with my family growing up and witness the pollution first-hand, whether as particles in the air that workers had to avoid with face masks or foul-looking waterways around the factories," she said. "These are vignettes in my mind that have made a lasting impression about the chemicals and processing required in the fashion industry."

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

A post shared by Huue (@huuebio)

Before we dig into the details about Huue’s technology, here’s a brief history lesson: Until the mid-1800s, dyes were derived from natural sources. Think plants, insects and other resources that grow in nature. Then English chemist William Henry Perkin discovered one of the first synthetic dyes while experimenting with coal tar, a thick, dark liquid byproduct of coal-gas production, creating a ripple effect that led to the $11.1 billion textile dye industry of today.

"You suddenly had dyes that were a lot more affordable, and also a lot more pure and effective for industrial use," Zhu reflected about the introduction of synthetic, petrochemical or coal-derived dyes. "But we all know, it also came with tradeoffs of environmental, and even in many cases, human health impacts."

On the global scale, textile dyeing is one of the leading activities to cause water pollution, according to the United Nations Environment Program.

From benchtop to the supply chain

Now Huue is using synthetic biology to go back to nature with its dye production. Hsu’s research focused on how nature creates color. Huue replicates the color production process native to Indigofera, a genus of plants that include species traditionally used for dye, through its proprietary microbe programming.

"That is the generalized principle behind how we do things at Huue. We look to nature for that inspiration, whether it's indigo blue or beet red or flamingo pink," Zhu said.

For now, the company is focused on indigo dye, but it eventually seeks to branch out to other hues. To do this, Huue identifies and sequences enzymes from the natural resources — such as the plants used to identify enzymes to create indigo.

When the company has an enzyme of interest, one that it wants to potentially use for dye, it expresses them in the microbial strain to see if it produces the target molecule. It also makes genetic edits to the strain to see if it improves the production of the target molecule.

When it has a promising microbial strain, it grows that in a bioreactor to see how much dye molecule it produces in a bigger, more well-controlled and better-fed environment. "This is a small-scale model of what the fermentation will look like in big fermentation tanks at scale. This is very similar to step 2, except using a bioreactor to grow the cells," Zhu said.

Huue can grow its microbes in vessels of any size — from petri dishes to processing tanks. At this point and to date, it has partnered with manufacturing facilities to run its process in tanks that are thousands of liters in volume. And it has mini replica tanks — 1 to 10 liters in size — in its Berkeley lab that it uses for R&D purposes.

After the fermentation process, it purifies the dye, which is then measured for yield and purity. Those measurements help determine how much indigo was created from the starting material and what percent of the dyestuff, an industry term for a substance that can be used as a dye when added to a solution, is indigo molecules.

A piece of cotton dyed indigo blue

Huue dye testing. Image courtesy of Huue.

Lastly, it tests the dyestuff by dipping cotton into a dye bath and squeezing it dry on a fabric padder. Then more measurements are taken to assess the fabric color, the color and wear qualities of the dyed fabric, and the dye bath itself.

"In that sense, we're creating this no-compromise solution that is both made from renewable and cleaner inputs, but also has the kind of purity, scalability and performance metrics that the industry really needs to be able to scale and adopt this on [a mass scale]," Zhu said.

Huue has been focused on turning its benchtop development into a product that’s a one-to-one, drop-in replacement into a fashion company’s supply chain — so the manufacturers won’t have to adopt new equipment or processes in order to integrate Huue’s dyes. The company has also been preparing the process for scale, so that it can work with large manufacturing facilities "to really start to service the industry in a meaningful way," according to Zhu.

Back in July, the company secured a $14.6 million Series A round, led by Material Impact, to launch and scale its indigo dye, which is used in denim. As of this summer, the Huue team was about 15 people strong, and Zhu expects the employee roster to grow to 25 in 2023.

"I think the ultimate goal is really servicing the demand that we're seeing coming in from our brand community for our cleaner colors," Zhu said.

Huue’s brand partners are under wraps but she noted that it’s "working and testing with household denim names that I think readers will know and love."

In its work with denim companies, Huue wants to demonstrate the value of its technology as that drop-in replacement that can be just as effective as the conventional petrochemical options.

Huue isn’t the only company on a color mission. Huue and others are seeking to disrupt the market for natural textile dyes, expected to grow from $725 million in 2020 to $1.5 billion by 2026 in the United States alone. (That figure also includes dyes used in other industries, such as food and beverage and cosmetics.)

Similar to Huue, England-based Colorfix uses a biological process to replicate pigments made in nature. Earlier this year, it received an infusion of $22.6 million in a Series B round, led by Swedish fashion giant H&M, which recently came under fire for its seemingly false sustainability claims.

There’s also Recycrom, which transforms fabric textile waste fibers into a fine powder that can be used as a pigment dye for fabrics and garments, according to the company site. It recently partnered with materials science and fashion company Pangaia to launch an "Earth-friendly" capsule collection using the dyes.

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