Thinking outside the bin at the world’s first zero-waste restaurant

“Our impact shouldn’t be measured by that,” says Douglas McMaster, waving a colourful cube of compressed waste plastic excitedly. That is Silo’s bin, such as they have one – and as a restaurant centred on the idea of ‘zero waste’, they don’t. What isn’t served is fermented; what isn’t or can’t be eaten is composted; and any packaging is either recycled or sent back up the supply chain.

What’s left is added to this pint-sized cube McMaster calls their ‘artwork’. “We don’t have a general waste bin. This is it.”

That’s it – and yet it isn’t it, as McMaster has already alluded. “It’s a symbol of thousands of innovations stacked all over each over in the supply chain. It’s what’s left, and we’ve made it a piece of art – but our impact should be measured by how we influence the restaurant industry and other industries, like design, craft – even technology and system design. We are at the sharp point of the arrow that is piercing industrialisation and killing the problem. That was a deeper chat than I anticipated,” he stops himself, suddenly shy, “but I can’t help myself.”

That is McMaster’s problem, or at least his problem as perceived by his critics. When Silo first opened, both the Guardian’s Grace Dent and the Evening Standard’s Jimi Famurewa decried the way their dinners turned into sermons on sustainability. What was supposed to be a brief tour of the dining room before our interview proper has become a discourse on the way zero waste is perceived – because McMaster can’t help but dive deeper into waste politics. “Our dining room is beautiful not for any superficial reason but because we need to change the way people perceive waste,” McMaster explains, gesturing to his circular tables made out of recycled plastic, his wall lights made from recycled wine bottles and the sheep’s wool on the ceiling.

He is not superficial, any more than his tables are superficial because the issue of waste is literally and metaphorically deep-seated. “It frustrates me when people assume zero waste is about making pesto out of carrot tops. It’s about systemic change. We hide waste in landfill, in a bin in the cupboard of our kitchens, because it is ugly. Zero waste is about taking the bin away, and working from there.”

Everything in McMaster’s Silo is centred on this premise — even the name, which refers to the various systems they have for keeping materials which can be reused, refilled or recycled. The enthusiasm with which he shows me these is as endearing as it is inspiring the refillable canisters of cleaning products from a closed-loop product company called Fill; the recycling silo, composting silo and a place where wine corks are piled high, ready to be collected and repurposed. Yet the word silo has another meaning too, one which points to the main challenge McMaster faces. In his dogged determination to show people the beauty and potential of zero waste, does he risk becoming siloed himself?

“I’ve had a lot of naysayers,” he says with a pained expression, when I ask about the criticisms that have been levelled against him. “It’s hard to swallow, especially when it’s some of the biggest reviews in our history – but I’ve learned to sever that connection between what we do and how it’s perceived.”

They don’t preach at Silo, he maintains — but they are passionate, and that passion is palpable. “This makes a lot of sense to the people who work here,” he says, pointing out the relaxed body language of the team laughing in the kitchen. “We’re not damaging nature, and we’re doing it in a way that is creative and compassionate.” You can try dining at this zero waste restaurant without learning about zero waste, but it’s a bit like just going to church for carols at Christmas. Inevitably, the gospel will make its presence known.

And rightly so, I’m minded to think, as I listen to McMaster. “Waste is a linear material that is not natural – or rather, it is born from nature, then processed in ways that make it unnatural, so it can’t be digested or decomposed.

We hide waste, because it is ugly. Zero waste is about taking the bin away, and working from there

“In the grand scheme of history, it has only just started to exist,” he says. Nevertheless, the rate and scale of its spread around the world is “cancerous”, he continues, with serious implications for global warming the methane from landfill sites is a major contributor toward climate change), soil and water health and biodiversity.

“What we are trying to do is design as many of those single-use materials out of our system,” he says. At its simplest, Silo takes the ‘reduce, reuse, recycle’ adage to its logical extreme. They don’t have plastic, bar what you see in their ‘art’ cube; the recycled plastic in their plates and countertops is post-industrial. The only thing they recycle is glass and cardboard. There is a hierarchy of waste, says McMaster: “Compost, which is good, and landfill, which is bad. Recycling is medium.”

Most of us manage to divert at least some of our waste into compost or recycling – but at Silo they are preventing as much as possible from entering the waste stream.

Fermentation is their first line of defence, he explains, opening a cupboard full of ferments stacked with an array of tubs and jars and dated with handwritten labels. Egg whites, oyster shells, pumpkin guts, shards of crackers, leftover dairy, scraps from a carcass – all are blended with salt and grain on which a koji-based fungus has grown. “Fermentation is so well practised in Asia but it’s not really understood in the west, to the point that we don’t even think to use it in our gastronomy. That is crazy,” says McMaster. “It’s the best way of turning all these nutritious scraps, which would otherwise be composted, into something of high value.” He pipettes small beads of velvet crab shell garum onto my hand to try. “This is gold.”

Some ferments are labelled ‘meta’: meta-dairy, meta-quaver and so on. Like much of Silo, this is easy to mock until McMaster explains it. “These are the result of layers upon layers of processing of scraps from different times – of loads of chemical reactions which we don’t really understand, which seems almost cosmic,” explains McMaster. It’s depth within depth – dairy compounded by dairy, I proffer, and he grins in recognition. “Right! And these favours — they’re so deep, so refined and special that they lead the dish. We build the dish around those favours. We taste the crab garum and say: ‘What goes with that?’ ‘Cucumbers.’ Then five months later, we taste fermented cucumbers and say: ‘What goes with that?’ And so on.” Instead of starting with fresh produce and ending at the bin, they’re starting with the bin – or rather, an absence of bin – and designing from there.

It’s hard to believe this will translate into delicious food, but Silo’s superpower is that it’s not good theory. Even Dent and Famurewa had to concede that McMaster’s dishes are a delight. Tropea onions with cuttlefish garum, Maitake mushroom with Szechuan pepper and miso – these encapsulate everything McMaster has said about zero waste, but they don’t taste worthy.

“These puffed crisps are made from a by-product of fermentation, so they’re a by-product of a by-product,” he enthuses about the crisp, golden crackers his staff are removing from the oven. Yet they are just great crackers, served with fresh goat’s cheese, to the naked eye.

I’m impressed – but I’m also stumped as to how Silo can be scaled down for an average household. McMaster’s answer intrigues: he’s been asked this before, many times. “I don’t know why I’m responsible for figuring out zero waste solutions for all humanity. It’s a big old design challenge,” he laughs. “All restaurants could do what we do, but the home is a different system. You can’t do whole animal butchery or fit a pail of cream in the fridge.”

Zero waste at Silo is a blueprint for restaurants and other industries. Zero waste at home is a separate issue – albeit one the indefatigable McMaster has recently started tackling.

The Zero Waste Cookery School is his online platform separate to Silo, featuring buying and cookery tips suitable for most budgets. “It’s not so radical as the restaurant, because I want it to be accessible,” McMaster continues. There is an acknowledgement there that for most people, eating sustainably can be hard. It’s an exciting venture for a chef who has spent over a decade at the zero-waste frontier; who was fermenting and buying in bulk long before it was trendy. He is earnest, and he is evangelical, and I can see why he’s been called self-righteous. But like that plastic cube, that seems a reductive take on someone working hard to do right and enable others to try.

Images: Laurie Fletcher