How I Turned the Basement of My Bar into a Cocktail Science Lab

From the outside, Scout looks like a regular East London bar. There's the unmarked front door (complete with tinted, one-way vision glass), minimalist booths, and bearded bartenders. But if you exit through a door at the back of the bar and descend a staircase, you'll find yourself in a laboratory.

"Just to warn you, it's pretty warm down there. We've got quite a few drinks on the go at the moment."

I'm with Matt Whiley, bartender and founder of several award-winning bars across the capital, of which Scout is the newest—and perhaps the geekiest. Every cocktail served here uses a ferment or vegetable vermouth that has been brewed in-house using ingredients like carrots, parsnip, beetroot, and nasturtium. In the downstairs lab, the fruits and vegetables are fed into centrifuges, placed into hot water baths, and then mixed in glass conical flasks.

Despite this Nutty Professor-esque approach to bartending, Whiley is keen to emphasise that, really, he's not doing anything new.

"In the modern era, everyone talks about science and labs but people have been fermenting and distilling things for hundreds of years," he says with a shrug. "We're just trying to find ways of drinking different things and using technology to alter the process. It's still a traditional method."

Part of the reason Whiley and his team of lab assistants—sorry, bartenders—are so into preserving is because they've limited themselves to using only UK-grown ingredients behind the bar.

"Scout is first and foremost about showcasing British produce. Yes, we're also a sustainable cocktail bar [the bar aims to be zero-waste] but it's about using what's available to us," says Whiley. "Whether that's picking some leaves from a fig tree down my street (I'm planning on surprising the neighbours with a bottled cocktail when the drink is ready) or sourcing shiso from a farm in Worcester."

I can't wait any longer to ask Whiley about the elephant in the room. Or rather, the leafy, green tree under hydroponic lights in the corner. Three lemons hang from its spindly branches.

He laughs: "We're having a go at growing a couple of things in the bar. But we're also using sea buckthorn juice in place of citrus. It has quite a pungent aroma but we've found that if we separate the solids from the fruit, the smell isn't as bad. So, we have citrus, it's just not lemon or lime."

Not until that lemon tree sprouts a few more fruit, anyway.

He adds: "It's about figuring out the right time and how to use the produce, or how to preserve things for the upcoming season, and when to preserve them. At the moment, for example, we have one ferment bucket empty. If something becomes available now, we can only select one thing that we think is right to stick in. Time will dictate what's available to us and what's right for that moment."

"Look up, they're all up there."

Lining the top of the cupboard are several large, white tubs filled different fruit and plant ferments.

"They're fermented in a similar way to wine," explains Whiley. "One of the ways is adding sugar, we're also using fresh yeasts (and in some cases re-using yeasts from previous ferments), and fermenting naturally with no yeast at all."

At Scout, fermenting needn't stop at grapes.

"We've got a birch, pear, and honey on at the moment, which is delicious, as well as a parsnip one. We're about to put rice and lavender on, which is amazing. There's celery and lemon balm. And a meadowsweet and nasturtium, which is a bit more interesting," says Whiley, ticking them off proudly. "We've got a gorse flowers ferment, which has a coconut-y flavour. We're going to do one with early season gorse flower and one late season to see what the difference is."

It sounds like a huge science experiment. Have there been any negative results?

"A while ago, we tried to ferment cauliflower. It didn't work," admits Whiley. "It actually tasted OK but the smell … wasn't very good. Now we steer clear of things we know will smell. We've got to a place where we think we're on top of it in terms of what will work."

Back upstairs, I take a peek behind the bar, which is lined with bottles labelled like a greengrocers' shelf. Beetroot sits next to white asparagus and parsnip and cherry nestles with strawberry.

"We live in a world where we need everything now and I think we've forgotten about what's available to us. I love bananas, I love tropical fruits but we don't necessarily need them all the time," says Whiley. "I think in the future, it might become harder to get stuff, so let's start reducing our carbon footprint now and look towards what we've got here."

Realistically, Scout isn't going to save the world. But if drinking a delicious cocktail can help the environment in one small way, I'll cheers to that.