Come into my bean room." As an opening gambit, it might as well have come from the lips of Roald Dahl's Willy Wonka as from Willie Harcourt-Cooze, or Wonky Willie as you might know him. But there's no psychedelic shapeshifting here, no lickable wallpaper or helpers of restricted growth bursting into song-and-dance routines. Harcourt-Cooze is inviting me into a brightly lit, windowless room, painted buttercup yellow. And it's stacked high with sacks of cacao beans.
"Smell that?" he asks. "Quite astringent isn't it? Not at all like chocolate." He's right, it smells nothing like you hope chocolate would smell. It's not sweet or creamy or rich. The room smells musty, the tangy, bittersweet scent clinging to my nostrils.
And the odour isn't the only thing that's unexpected. If you believe what you watch on TV then you probably think Willie Harcourt-Cooze is a scatty, posh bloke with a penchant for 100 per cent cacao and a very patient wife. To a certain degree that's probably a fairly good description (I can't vouch for the patience of Mrs Harcourt-Cooze because I didn't meet her) but Willie is a man on a mission to bring top-notch chocolate to the masses in his own chaotic way. But I suspect there's more to him than floppy hair and charm.
Willie was last seen on screen in a Christmas special using his premium cocoa in a range of festive dishes – from mince pies to a slow-cooked whole lamb. Before that we'd watched him in Wonky Willie's Chocolate Factory, the documentary that traced his progress in trying to become the first British chocolate maker since Cadbury to grow, process and make chocolate. It's no modest ambition. His next foray into television documents the latest phase of his chocolate "revolution" which will see him bring his first bar of chocolate to the masses.
Tucked at the back of a small industrial estate in Uffculme, Devon, the factory is an unremarkable, flat-roofed building. Not exactly magical. The Wonky Willie tag is obviously a gimmick dreamed up for, or by, the "TV people" as Harcourt-Cooze calls them, but it's still a bit of a shock to find the headquarters so scruffy. Even on a cold and sunny day, with the melted snow dripping from the gutters and puddles shining in the bright light, it looks ramshackle. The kind of place you come to buy cheap tyres or get your car cleaned. Not exactly the place where you might expect dreams to come true.
But that is what's happening here. It's been 12 years since Harcourt-Cooze bought his cocoa farm – El Tesoro (Treasure) in Venezuela, planting it with 10,000 cacao trees. He had sold his flat in London and was on an adventure around the world. He'd been trekking through the South American country with his new wife, Tania, mainly on horseback, when a tip from a stranger sent the couple into the mountains near the beach resort of Choroni. It was there that he found his treasure. He instantly fell in love with the hacienda nestled in a national park, but it took him two years to persuade the owner to sell it. For six months, the couple lived on the beach. (From that let's take it as read, Mrs Harcourt-Cooze has patience to spare.) My head filled with images of mountains cocooned in clouds and lush cocoa plantations, I'm struggling to understand the drafty building I'm now standing in.
"The factory is built from the dump," he says proudly. "The toilet, the doors, the lot. I'm famous down there. The dishwasher was 20. Even the front door, it's the old door of a church or something." Filled with machines that look like they've come from a different age, most of which have been stripped down and repaired by Harcourt-Cooze (for a chocolate-maker, he's got hands like a car mechanic – calloused and rough, but the dark smears under his fingernails are cacao rather than motor oil). There's a roaster, a grinder, a conching machine and a conch refiner.
"I love these bits of machinery," he says as we walk round. "When I saw them I knew that everything was going to be OK. This roaster is 100 years old." He fires it up and it makes a hellish noise. "The beans roast in hot air…" (at least I think that's what he's saying. I can't really hear him over the din). He continues his explanation and I smile, missing most of it. "It sounds like a monster," he says with a grin, as he switches it off.
Bolts and gears, pistons and bearings – he talks me through every aspect with obvious fascination. "It's like a sort of big boys' Meccano project. I'd never done anything as challenging as this," he says looking at the conching machine with schoolboy pride. "It's been fantastic, to be honest with you."
Harcourt-Cooze is under real pressure at the moment, although, making me tea and taking his time to show me round, he's too nice to show it. He's knee-deep in the next phase of his project – making chocolate bars rather than the pure cacao for cooking. "Chocolate is a challenge," he says. "It's much more sensitive than cacao. I've got six weeks to produce bars. But I've finally got my recipe and I like it."
Harcourt-Cooze looks as ramshackle as his factory. Dressed in sweatshirt and jeans, with long, straggly hair, he seems pretty tired. It's no wonder. The factory is a dream but it's also a business and he's got to make it work. He's a romantic – full of stories and wonder – but there's an edge to him which comes from the hard graft of making something from nothing. Until the end of January when he hired Mike, a Polish builder looking for a change of career, Harcourt-Cooze had roasted every one of the 40 tonnes of cacao beans processed in the building.
For the last two years, he's been, "much to the horror of everyone," he says, in the factory seven days a week. The "everyone" he refers to is his wife, Tania, and their three children Sophia ten, William, eight and Eve, five.
The Channel 4 documentary series that followed Harcourt-Cooze firmly established Willie as the dreamer and Tania as the long-suffering, sensible sidekick, constantly trying to keep his feet on the ground. I suspect the reality is slightly different.
"I'm not sure I agree," he says, smiling. "But I couldn't have done it without her. We've split it – she's not machine oriented but she's held the family together. She's a great artist so she's had lots of input in the way things look."
And what about his children, is he building an empire to hand on to them?
"Well, if they want to," he says noncommittally. "We'll fight about it I'm sure. I don't think that far ahead. I know one thing: I won't be taking it with me. I'm just going to enjoy it while I've got it. The kids have never been spoiled so you worry that if it is all successful that it becomes that second generation thing. Whatever it is they want they'll have to go out and work for it like I did."
Harcourt-Cooze's father was Burmese and his mother Irish. His father fled Burma during the Second World War and when Willie was four, the family settled in Ireland, where they bought a small island off the coast. "We grew everything," he says. "We made cheese, yoghurt. We salted our own fish. I definitely had an unusual childhood. That's why I don't worry about my kids in Venezuela. They're resilient, as we were.
"We lived in the wilds of Ireland until I was 11 and then I came back (to England] for a year. I hated it. I went back again and went to the comprehensive in Cork until I was 15."
Harcourt-Cooze's father was set on a good education for his son so it was back to England for Willie to do A-Levels. He didn't finish them, though. Halfway through, having been thinking about a career as a property developer like his father, Willie was stabbed while on a night out with friends, and everything changed. The exams were shelved and suddenly, with a greater sense of his own mortality, Willie wanted more from life than a portfolio of property. Then, when he was only 18, his father died. "It was a definite direction loss," he says. "It's all for a reason." For the first, and only time, he's lost for words.
After years of travelling, wandering, following tangents, when Harcourt-Cooze happened upon El Tesoro he knew it was for him. "We're very lucky to have that farm," he says. "I've travelled the world and that place has definitely got something special."
The Venezuela dream went a little awry when the country's president, Hugo Chavez, ordered an investigation into Harcourt-Cooze's export business after a local woman accused him of not paying a fair price for cacao beans and exploiting local labour, but the subsequent investigation found no such thing; "nonsense" is how Willie describes the claims.
"On a visit to the local village, Chavez was talking about how famous the cacao is and how beautiful it is and this young girl took the chance to say that I didn't pay anything for my beans, that I exploit people and I'm a millionaire. But the ridiculous thing is, I don't buy my beans from that area, I grow them. And the beans I do buy, I do so in the free market. The woman listed about 15 people and when they came to do their investigation, it turned out the people were friends of mine and they were horrified.
"I've been very conscious of these issues right from the beginning because I'm a cacao farmer. I sold my beans to a very smart chocolate company which paid me very low prices. I've always been on the receiving end. I called it Willie's Cacao as a brand but it's also Venezuelan Black because I didn't want to be accused of being an exploiting foreigner."
There's certainly more of a business brain underneath that nest of hair than Harcourt-Cooze tends to show, but that's not to say his approach to his venture is conventional. "There are probably all sorts of things I could do to make more money but once you get into that stuff – price points, shareholders ..." his sentence trails off as if the words taste bad in his mouth, like cheap chocolate. "I'm lucky because it's a family thing and by that I mean it's my wife and I, our family. I don't have anyone breathing down my neck. I don't have anybody telling me we're not making enough money.
"I just think, with these things, it's about producing the best product that you can. Work out the rest later. For me everything's done on the back of a cigarette packet, whether there's money in it or not. As long as there is potential then you can work out the finer details later."
Once the chocolate bars are made and the next television show is behind him Willie wants to get back to what led him to where he is now. He doesn't want a bigger factory ("I think that might just mean bigger problems") but what he does want is to get back out there, discovering the beans that will allow him to make premium, single estate chocolate bars.
"Sourcing the single estate beans – all along the equator from Indonesia to Mexico – would be exciting," he says. "That's how I got here. I mustn't forget that. The secret is the beans."
It's not a bad plan, as it goes. And I'm impressed that the wanderlust hasn't left him. The look of envy must be visible on my face as I stuff more of his delicious early run chocolate into my mouth.
"Listen, I'm very lucky," he says, in that genial way that makes him so suited to TV. "I'm spoiled. I've found something I like doing and I can do it. And it's come round for me. I was reckless – going into Venezuela was reckless. OK, I put the work in, but I was lucky it was a cacao farm not a banana farm; it might have been a coffee farm but no, it was one of the best cacao farms in the world.
"Quite lucky, really, actually."
You could say that.
• Willie's Chocolate Factory Cookbook by Willie Harcourt-Cooze is published by Hodder & Stoughton, priced 20. Willie's Chocolate Revolution: Raising the Bar screens from 7 to 9 April on Channel 4 at 8pm.