Cowless cheese: it's possible! Hille van der Kaa on rebuilding dairy from a stainless steel cow

‘If I look back, that moment in the barn didn’t come out of nowhere. It was more like the final push in something that had been building for years.

I’ve been vegetarian since I was eight. But I managed to keep dairy in a blind spot for a long time. I find it strange now that it took me until halfway through my thirties to really confront what that system looks like.

Professionally, I was editor-in-chief at the time. Journalism was my world and I worked long hours. I met Jaap years earlier when I interviewed him about The Vegetarian Butcher (De Vegetarische Slager). He and Nico had already proven that you can challenge something as culturally loaded as meat and still build a serious business. What struck me was that they weren’t activists throwing stones from the outside, they were system thinkers. Strategic and long-term.

After they sold the company, they started asking: what’s next? Dairy was the obvious elephant in the room. When a laboratory in Ghent became available in 2019 and they decided to take it over, the idea became tangible. Around that time, I was already questioning my own work. We framed debates about livestock farming, but we didn’t always show the full picture. It started to grate.

Then came that experience at the dairy farm, just after I became a mother. It didn’t create my discomfort, it crystallised it. It made looking away impossible.

Joining Those Vegan Cowboys felt like alignment. As if something that had been simmering, personally and professionally, finally found direction.'

‘It started with animal welfare. That’s the emotional root of it. But over the years it became business – and I say that without hesitation.

I’m not just an idealist. I studied at Nyenrode, a business university. I love building something that works commercially. What we discovered is that producing casein – the protein in dairy – through fermentation isn’t only better for animals and the climate, it can also be economically stronger. Our proteins can be more functional than animal casein. And eventually cheaper. That matters.

Jaap once said: ‘I give this one percent chance of succeeding, but that one percent is big enough.’ Impact only counts if you can scale it. And scale means competitive pricing. We’re not building this for vegans – lovely as they are. We’re building it for the mass market. For my own family members, who love regular cheese.

This technology has a long timeline. About seven years to proof of concept and then ten to fifteen to become commercially attractive at scale. We’ve always known that. It’s not romantic, it’s disciplined.

So yes, it began with idealism. But today it’s realism. And I think that’s exactly why it has a chance.’

‘Nico allegedly once said to Jaap, half-joking: “We’re just a bunch of cowboys.” Adding ‘Those’ made it stronger. It gave it attitude.

From the beginning, we knew we couldn’t present this as biotech. That word feels cold and clinical. A bit scary even. We learned from The Vegetarian Butcher that if you want to change a system, you have to build a world around it that people want to step into.

Jaap came up with the stainless-steel cow – just a silly stock image at first – and we printed it life-size on cardboard. It was almost ridiculous, but it worked. People took pictures with it. Children wanted to kiss the cow. That’s when Margaret was born, our Iron Lady.

Since then, she’s become our symbol. The stainless-steel cow that replaces the biological one. It sounds playful, and it is. But underneath that playfulness is something quite serious: if you’re going to introduce something as radical as dairy without cows, you’d better make it feel human first.’

‘The first two years were intangible. You’re surrounded by scientists in a lab and someone yells, “We’ve made a huge breakthrough!” but you don’t see anything. There’s no cheese on a shelf, no proof in the real world.

That changed the moment we were able to produce casein and share it with industrial partners. One of them was Hochland, one of Germany’s largest cheese producers, the kind of company that makes the processed slices for fast-food burgers.

They tested our casein and we started talking seriously about collaborating. During a visit, they gave us a tour of their production line. You stand next to this enormous line where huge blocks of cheese move past continuously. It’s just one line and it’s already gigantic. I remember standing there thinking: this is one line, there must be tens of thousands like it worldwide. 

Someone said: “If you can produce this at scale and at the right price, it’s a no-brainer for us.”

And in that moment it clicked. This wasn’t a vegan experiment anymore: this was infrastructure. If this works, it could be a revolution. I actually blinked away a tear about this later.'

‘Yes, genuinely. I think many people assume we’re fighting the dairy industry. But what surprised me was how open large parts of it were.

Industrial food companies buy milk as an ingredient. They don’t have an emotional bond with the cow. They need reliable, affordable inputs. And they’re under enormous pressure to reduce CO₂ emissions. That’s extremely difficult to achieve with conventional dairy.

Even farmer cooperatives came to speak with us. Some out of curiosity, some strategically. I remember one representative saying very honestly: “I don’t want to get rid of my cows. But I’m realistic. The number of cows will go down. I can either go down with them, or I can explore something new.”

With fermentation-based casein, you’re not shaving off a few percentage points in emissions. You’re talking about potential CO₂ reductions of around 80 percent. That’s why most serious players don’t see this as a threat, but as an opportunity.’

‘Honestly, we experience surprisingly little resistance. Most of the cheese people eat – on pizza, burgers, in plastic packs – isn’t romantic or artisanal. It’s industrial. Around 95 percent already uses microbial rennet, which is also made through fermentation. Biotechnology has been part of cheese for decades.

The nostalgic image – the cow in the meadow, the Dutch dairy girl – is powerful, especially in the Netherlands. But it’s a fantasy. For most consumers, the question isn’t tradition. It’s price and functionality. And if you look closely at what’s already on your slice of pizza, our product is actually less ‘scary’ – no antibiotics, far lower emissions. So before people worry about us changing cheese, I’d suggest they first look at what they’re already eating.’

‘What it has cost me is a certain kind of innocence. The longer I work here, the more I see. And some of those things I would rather not have seen. Ten years ago, I could easily eat kilos of cheese a year. I genuinely enjoyed it. If you’d put a piece of pecorino in front of me, I would have been happy.

Now it feels different. Once you understand the system behind it, you can’t quite separate the taste from the story anymore.

I’m fully vegan now. I sometimes taste for work, but otherwise I don’t eat animal products. That change was gradual. Casein is actually mildly addictive. If you stop eating it regularly, the craving fades. It’s a bit like quitting sugar. At some point, you simply don’t miss it anymore.

But it is a form of letting go. You lose that naïve enjoyment. At the same time, it has given me clarity. My work and my convictions no longer contradict each other. And that feels… lighter.’

‘It’s absolutely not a done deal. We still need millions to scale and development takes years. Integration into large dairy factories has to work seamlessly. I would never say Those Vegan Cowboys will succeed one hundred percent. That would be naïve.

I don’t doubt that we should be doing this. I just don’t pretend the outcome is guaranteed. And if another technology comes along that achieves the same faster or better, I’ll be the first to applaud, even if that means our own company becomes redundant. The mission is bigger than the business model.

I used to earn three times as much. This isn’t about personal gain but about whether we can move the system.’

‘Perseverance and patience. I come from journalism: my deadlines used to be thirty seconds. Now they’re ten years. In ten years, everything can happen. You need to tolerate uncertainty.

What helps is that the mission is larger than the company itself. That gives you almost endless motivation. But you need a business mindset alongside it. We measure every partnership against impact. We could work with smaller players all day, but if you want real change, you need the biggest customers. Idealism without scale doesn’t move systems.’

‘If this works, we simply need far fewer cows. That would change the Dutch landscape. Large areas now used to grow feed could return to nature. Cleaner air. Healthier rural regions. Farmers transitioning into new models, perhaps even producing with technologies like ours.

And people would still be eating cheese.

We won’t do it alone. There are maybe five serious players worldwide working on this. Not all of us will survive. Others will build on what we started. That’s how transitions work. If people look back, I hope they’ll say we were early – and that we helped make it normal.’