Working with the Grain

Arda Biomaterials is using beer waste to create scalable, plastic-free leather as investors seek circular economy innovations.

On this week’s episode of Profit Meets Purpose, TJ Mitchell, Co-founder and Chief Technology Officer of Arda Biomaterials, explains how waste can be repurposed to address the need for sustainable materials. 

Listen to the full episode here.

After completing a PhD in supramolecular chemistry at Oxford, Mitchell wanted to apply his research to real-world challenges. 

That opportunity came through Entrepreneurs First, an intense two-month founder-matchmaking programme that supports the creation of new startups. Selected to join the cohort, he describes it as “Dragon’s Den meets Love Island”. 

It was there he met his co-founder Brett Cotten, a biotech entrepreneur from New Jersey. Together, they set out to tackle sustainability by finding ways to remove animals and plastics from supply chains.

Their story shows the importance of entrepreneurs being willing to recognise the need to pivot, as well as the importance of working with the grain when it comes to developing scalable processes and developing relationships with established industries and brands. 

A pivot from food to fashion

While exploring ideas on which to base their new venture, the pair spent time with independent brewers along London’s Bermondsey Beer Mile, just a short walk from Entrepreneur First’s offices. Their first concept was to extract protein from ‘spent’ grain, leftover from the brewing process, and use it to enrich plant-based foods. Around 200g of this waste product is produced for every litre of beer. They even pitched the idea to meal-replacement brand Huel, but the economics quickly proved unworkable.

“To make it viable for food, you’d need massive scale, and the regulatory hurdles were huge,” Mitchell says. He adds that maintaining product consistency would have been almost impossible when working with a variable waste material. Looking back, he believes there was strength in “knowing when to pivot and pivoting fast”.

Drawing on his chemistry background, Mitchell began to wonder whether those same proteins could be turned into materials instead. Research from Cambridge University had shown that plant proteins could be manipulated into collagen-like structures with the same fibrous makeup that gives leather its strength and flexibility. “It clicked that we could make a material with the feel and performance of leather but without animals, and crucially, without plastic,” he says.

Early experiments took place in Mitchell’s kitchen. “The first sample looked like a flapjack,” he admits. “I even used formaldehyde once - a terrible idea. My kitchen wasn’t ventilated, and I ended up with a splitting headache.” But the experiments were enough to prove the concept.

Entrepreneurs First invested £80,000 for a 10% stake, and Arda Biomaterials was born. Mitchell concedes it was a sizeable share to give up for a modest investment but credits the programme for introducing him to Cotten and helping him found the company.

From pint to prototype

Arda’s process begins with a spent grain, the dense husk left after all the sugars have been extracted. In many inner-city areas, where the microbrewing sector has surged in recent years, brewers pay to have this waste collected and removed. Arda instead repurposes it, extracting the protein and restructuring it into nanofibrils that replicate the properties of collagen. The result is a flexible, durable material that mirrors the look and feel of leather.

Mitchell is quick to point out how this differentiates Arda from most so-called vegan leathers on the market. “A lot of plant-based leathers use plastic coatings to achieve durability,” he says. “It’s greenwashing, really. Our material is 100% bio-based.”

The team’s first major test came through a partnership with Beavertown Brewery, known for its popular Neck Oil pale ale. The collaboration produced a limited run of cardholders made from Beavertown’s waste grain. “We made about 30,” Mitchell says. “It was small, but it proved we could create something beautiful and functional.”

Mitchell believes the story behind the material has captured the market’s imagination. Brewers and whisky distillers, he says, are natural storytellers - masters of brand, craft and heritage - making them ideal partners for Arda to collaborate with. “It’s the perfect crossover with brands that know how to connect with consumers,” he says. “I always joke that we need a Guinness x Gucci leather jacket.”

With Arda actively looking to develop its links with established brands in luxury consumer sectors, the joke may yet become reality. 

Circularity in action

Arda has attracted significant investment. In 2023, the company raised £1.1 million in seed funding led by Clean Growth Fund, a venture capital fund that invests in clean tech entrepreneurs tackling the climate crisis, alongside a collaborative £800,000 grant from Innovate UK. The grant brought in researchers from King’s College London and Queen Mary University of London to study biodegradation and fibre spinning. “Having academic partners gave us credibility,” Mitchell says. “It showed investors we were serious about the science.”

Earlier this year, Arda closed a £4 million round led by Hamburg-based Oyster Bay, an early investor in Oatly, the alternative-milk company. “They’d never invested in materials before,” Mitchell says. “But because we touch the food industry through brewing, they made an exception.”

Today, Arda has a 13-person team, 11 of them scientists, and a new lab equipped with industrial-scale extraction and mixing vessels. “We’ve gone from making two-litre batches in the kitchen to 1,000-litre systems. Our next goal is continuous production,” Mitchell explains. 

The company has joined the 100+ Accelerator, a programme run in partnership with AB InBev, the world’s largest brewer, which has led to a paid pilot collaboration. “We’ve already made materials using waste grain from some of the world’s most famous beers,” Mitchell says, careful not to name which. “The pilot’s going really well.”

The ultimate vision is decentralised manufacturing where facilities co-located with breweries, turning local waste into local materials. “Imagine a whisky distillery in Scotland producing a leather alternative for the luxury market,” Mitchell says. “Or breweries in Germany supplying material for car interiors. It’s circularity in action.”

The science of scale

Arda now faces the challenge of scaling production to meet demand from fashion and automotive brands. Its pilot with BEEN London, an award-winning East London design house, yielded two bag prototypes that demonstrate the material’s commercial promise.

“We’re focusing on luxury brands because they have the strictest performance standards,” Mitchell says. “Once we hit those, we can move downmarket.” ARDA’s aim is to achieve price parity with plastic leather and eventually undercut animal leather, made possible by the low cost of its feedstock.

In five years, he hopes Arda will have commercial facilities across Europe and partnerships with major fashion houses and carmakers, as well as producing a wider range of materials.

Investors remain cautious after other companies fail to scale operations, for example Mylo  which was backed by Stella McCartney or Natural Fibre Welding. Mitchell understands why. “People have heard the hype before,” he says. “But the difference is that our process already fits into existing manufacturing systems. The first half looks like a brewery, the second like a plastics plant. That means we can scale quickly without reinventing industrial infrastructure.”

Listen to the full episode here.