Thick, brown liquid pours from a pipe above my head. To my right, a multi-armed machine spins dozens and dozens of giant eggs round and round, coating each plastic shell with a thin layer of chocolate that, come Easter Day, some lucky recipient will shatter, their thoughts on anything but the physics of its centrifugal creation.
The atmosphere is thick with calories; the room perfumed with the sweet smell of every child's ultimate fantasy. I feel I should be clutching a golden ticket, for I am standing inside a chocolate factory that is every bit as exciting as its Roald Dahl billing.
OK, the Oompa-Loompas are a bit thin on the ground, replaced instead by an army of white-coated, green-hair-netted Poles, busy assembling the various Easter characters that now give 21st-century meaning to the annual chocolate fest formerly known as a religious holiday. But that isn't lessening the fun. On one side of the factory, a herd of miniature cows whizzes past on a conveyor belt, like holidaymakers squeezed on to an airport travelator; on another, a brace of baby ducks makes a similar journey, bound for the shelves of one of the major retailers that Kinnerton Confectionery supplies.
It is the busiest time of the year for the Fakenham factory, the largest in a rapidly shrinking field of British chocolate makers. Although, as Clive Beecham, Kinnerton's managing director and visionary – he pioneered selling chocolates shaped like your favourite cartoon character more than three decades ago – puts it: "That's rather like saying Morgan is the UK's biggest car manufacturer."
It should be a bumper Easter for Kinnerton, which makes one-third of its sales during the spring chocolate season (so-called because chocolate is increasingly a Valentine's and Mother's Day gift), because a nation of chocolate lovers is feeling more than a little bitter over the sale of its beloved Cadbury to the US giant Kraft. "There's a real disillusionment that it's gone. It's something about the way we let our national icons go, which wouldn't happen in France. And, all else being equal, I do think people like to buy British," says Mr Beecham.
Nevertheless, Britons will still spend around £3.6bn this year on chocolate – and around £200m of that will go on 80 million Easter eggs. And the market is growing. It doubled between 2005 and 2007, according to the market research firm Mintel and is expected to rise by a further 17 per cent over the next five years. The average Briton will eat around 18 pounds of chocolate this year.
Mr Beecham stops short of predicting that the national sweet tooth will favour his chocolates over Dairy Milk. The British public loves Dairy Milk, but he is bound to pick up some extra sales. Not least because this year his factory is riffing on that wave of jingoism by pushing a new British chocolate recipe for Marks & Spencer. It's more chocolatey, made with 35 per cent cocoa (but if you're in the growing camp that prefers dark chocolate you might struggle to notice the difference).
One area where Kinnerton does pick up extra sales is in the nut-free market. In 1999, the Norfolk-based site became the world's first manufacturer to create a nut-free chocolate-making zone, separated from the rest of the premises by a brick wall that cleaves the site in two. Mr Beecham calls the divide the factory's Iron Curtain and, as with the old Berlin, there is no fraternising between the residents of the two sides.
In fact, so strict are the factory's nut rules that at one point I feared my Charlie Bucket illusion might be thwarted. Under instructions not to secrete any nuts about my person, or, indeed, consume any in the previous 12 or so hours before my visit, I thought I had complied until I saw our photographer's camera getting the once over from the nut equivalent of a Geiger counter. I had forgotten to warn him to avoid the muesli that morning. Fortunately, we passed the test.
Kinnerton offers its nut-free guarantee to reassure the one million or so children (about 5 per cent of kids) who are allergic to nuts, although you will find the pledge only on its own-brand lines and not the ranges it produces for M&S, Sainsbury's and Tesco.
Setting up what is, in effect, a separate factory was no small undertaking, Mr Beecham explains, "considering that nuts are the tools of a confectioner's trade". But he knows the risks of slipping up: one lactose-intolerant child in north Wales went into anaphylactic shock after eating a supposed dairy-free bar that had got mixed up. "His mother came close to suing us." But one golden ticket later and a luxury dark-chocolate egg bearing the boy's name – James Elliott – and all was well.
Mr Beecham fell into the chocolate business after his father, who made toys, suggested he copy some Mickey Mouse lollipops he had seen on a trip to Disneyland. At the time, no one else was making chocolate characters, so Mr Beecham quickly realised he was on to something.
Today, the company creates more than 400 new products every year, and has licences for just about everything from Hello Kitty to High School Musical. It is even working on a chocolate of Stig, from Top Gear, although the prototype looks more like a frogman. "We'll have to sort out the goggles," concedes Mr Beecham.
As for whether The Stig could ever rival Lindt's ever-popular gold, foil-wrapped bunny in the nation's Easter baskets, well, that seems unlikely. But a nut-free version and Kinnerton might just be on to something.