PPTI Web Exclusive: The Good Food Institute's Adam Leman on fermentation’s next frontier

For Adam Leman, fermentation is more than a production method – it’s a tool to transform the food system. Here, he discusses the tensions between efficiency and scale, the role of sidestreams, and how carbon-fed microbes could redefine sustainable protein

“Fermentation is not new – it’s one of the oldest technologies in food,” says Adam Leman, Principal Scientist for Fermentation at The Good Food Institute (GFI). “But what’s new is how we’re harnessing it to meet today’s challenges of climate change, protein security, and sustainability.”

That tension between tradition and innovation runs through Leman’s career. Trained in molecular and systems biology, he first encountered the power of microbes not in food, but in pharmaceuticals and industrial proteins. “My fascination with fermentation came before the emergence of alternative proteins,” he recalls. “But once I saw the promise of food proteins, that sealed the deal for me. Food, and protein in particular, are a perfect match for microbial production. It’s efficient, controlled, sustainable, and builds on a long history of fermentation in food.”

GFI as catalyst

At GFI, Leman works on the science and technology team, which aims to accelerate innovation while also shaping the broader food system. “We act as a catalyst for the ecosystem,” he explains. “We produce open-access analysis that connects stakeholders with the most promising opportunities and critical barriers. Our evidence-based work can spark change across supply chain optimization, product development, and even policy.”

That dual role – technical and systemic – reflects how alternative proteins must advance. “Ultimately, enabling progress means a world where alternative proteins cost the same or less than animal ag-derived options, taste as good or better, and are widely available,” Leman says.

Beyond the ‘third pillar’

Fermentation is often grouped alongside plant-based and cell-cultivated meat as the so-called ‘third pillar’ of alternative protein. But Leman suggests the label may no longer fit. “Within manufacturing, those distinctions are clear – the technical stacks are different,” he acknowledges. “But in the end products people buy, the lines blur. You already see plant-based products with cultivated meat as an ingredient, fermentation-derived proteins enhancing burgers, or mycoprotein blended with plant proteins. What consumers experience is the synergy, not the separation.”

Efficiency versus scale

If fermentation’s potential is clear, its economics are not. As Leman describes, the industry faces a paradox: the most efficient systems require the biggest – and costliest – facilities.

“Technoeconomic models show that efficiency comes with scale,” he says. “Labor becomes more efficient, equipment costs are amortized, processes streamline. But the capital outlay is huge. So, companies hesitate. You want to demonstrate demand before you maximize your footprint – but without scale, you can’t hit the cost targets.”

The result is a waiting game for first movers. “I think the first substantial green light will come from novel CDMOs such as Liberation Labs,” Leman notes. “But we shouldn’t forget examples like Marlow Foods’ Quorn plant or long-standing yeast production facilities – they’ve proven it can work.”

“Food is price-sensitive. Consumers can and do switch away from products if they’re too expensive. That makes investors cautious – but once that first-of-a-kind facility arrives, the floodgates will open”

The challenge is sharper in food than in other industries. “Food is price-sensitive,” he says. “Consumers can and do switch away from products if they’re too expensive. That makes investors cautious. Yet we already see precision proteins – lactoferrin, nutraceuticals, oils – that can be cost-competitive at low inclusion rates. Commodity proteins will follow once that first-of-a-kind facility arrives, and then the floodgates will open.”

Where breakthroughs are happening

Asked where innovation is most promising, Leman doesn’t pick one. “Bioreactor design, strain engineering, and systems integration – all three are essential,” he says.

Cheaper, smarter bioreactors could reduce costs and enable continuous fermentation. Solid-state fermentation remains underexplored but potentially transformative. Strain engineering, meanwhile, can drive productivity and yield. “If we can shorten fermentation time or get more product per unit of feedstock, that’s a step-change in economics.”

And then there’s integration. “Begin with the end in mind,” Leman emphasizes. “Can we design strains that simplify purification? Media that reduces filtration requirements? Purification steps that preserve protein solubility? Thinking holistically across the process is key.”

Learning from other industries

Fermentation pioneers often look to pharma or industrial enzymes for guidance. But Leman cautions against over-reliance. “Enzymes are the closest analogy, but their economics differ – value is in function, not volume. Pharma, meanwhile, is the Formula 1 of biomanufacturing – high cost, high precision. We need road cars, not race cars.”

Still, he points to lessons in joint ventures. “The biochemical fermentation industry shows how partnerships let each player focus on strengths while creating commercial pathways. That model could work for food proteins, too.”

Gas fermentation: food without crops

If scale is one frontier, carbon is another. Gas fermentation – using microbes to convert CO₂ or methane into food – is gaining traction as both climate tech and food tech.

“Food from gas fermentation can be part of the carbon-capture solution,” Leman argues. “Carbon pulled down or diverted from emissions can go into sequestration, fuels, materials – and food. It won’t solve everything, but it’s part of the tech stack.”

The approach also buffers against agriculture’s vulnerabilities. “We’re losing arable land, facing more plant pathogens, and experiencing volatile crop yields,” he says. “Producing food partially outside of agriculture can stabilize supply and reduce land pressure.”

But the infrastructure requirements are high. “You need co-location with emitters like cement or steel plants, plus affordable renewable energy,” Leman explains. “Electricity is a major input for gas transfer to bioreactors. So, scaling this depends on the wider energy transition.”

What about consumer acceptance – eating food made from CO₂? “All our food already comes from CO₂,” Leman points out. “Plants fix carbon through photosynthesis. Microbes just use different carbon-fixing mechanisms. With a bit of education, I think consumers will see it as a natural extension.”

The promise – and pitfalls – of sidestreams

Another avenue is valorizing agricultural sidestreams, from crop residues to food processing waste. “It’s technically possible,” says Leman, pointing to bioethanol’s use of corn stover and bagasse. “But cost remains a barrier – refined sugar is still cheaper than breaking down lignocellulose.”

That said, food markets may shift the balance. “Food is higher value than fuels. If electricity costs fall, enzyme efficiency rises, and outputs are higher value, sidestreams could make sense again,” he says.

“In five years, I hope fermentation is completely boring – in the best way. I want consumers to see it as part of their regular rotation of products they buy and enjoy”

Some sidestreams are particularly promising. “Food processing waste is already centralized, making it easier to collect and convert. Think vegetable starches, fruit juices, or grain by-products. Other streams such as husks and stover are abundant but distributed and harder to process. The key is affordability and consistency.”

But he warns against silver-bullet thinking. “If sidestreams were easy, they’d already be mainstream. Safety, quality, and regulatory frameworks will all be essential.”

Fermentation also complements plants. “Plant proteins are great for yield, but microbes can enhance flavor and functionality,” Leman explains. “Fermentation-derived proteins add texture, microbial oils contribute complex flavors, and yeast proteins improve mouthfeel. The synergy lets plants punch above their weight.”

Barriers, hopes, and measures of success

If he could wave a magic wand, Leman would remove the economic barriers to infrastructure. “Lowering the cost of building facilities would unlock everything else,” he says.

In five years, he hopes fermentation will be normalized. “I want it to be boring, in a good way,” he smiles. “Consumers should see fermentation-derived proteins on shelves as part of everyday products they buy without hesitation.”

And success? “Price parity is essential, but it’s a waypoint. The real goal is systemic: reduced land pressure, stable protein supply, lower carbon footprint. That’s what will define fermentation’s impact.”

A patient revolution

The pace may feel slow, but Leman reminds us that food systems evolve over generations. “Worldwide industries can take a generation to adapt and course correct,” he says. “So we need patience – and we need to celebrate successes along the way.”

Ultimately, his optimism comes through. “Fermentation is a natural wonder that humans have harnessed for thousands of years,” he concludes. “Now, with new tools and urgent needs, we can harness it again – to build a sustainable, secure, and delicious future.”