Great Shakes: Meet the remarkable jelly mongers

They've made Calpol cupcakes, a 6ft gingerbread Gherkin and a walk-in G&T cocktail. But it is for their remarkable jellies – and sense of the ridiculous – that Sam Bompas and Harry Parr have caught the eye of everyone from Heston Blumenthal to Richard Rogers

Visiting Sam Bompas' cramped flat in Southwark, south-east London, is an experience akin to encountering Willy Wonka during his freewheeling student days.

On entering the front door, I have to fight my way past a 6ft-high crate containing a gingerbread replica of Norman Foster's Gherkin; then, upstairs, in the disarray of the kitchen, as business partner Harry Parr prepares some chilli sauce for a catering commission, I find Bompas working on some rather more outré concoctions: a tobacco- and coffee-flavoured essence and – pushing food nostalgia to its most infantile limits – Calpol-flavoured cupcakes.

Later, during our interview, Bompas intermittently leaps up from his chair to show off his assorted ingredients and wares. These include a jelly mould of the Brighton Dome, a jar of leeches and a bottle of liquid ether. "We had a breakfast the other day where we got the ether cocktails going... they were big in belle époque France and again with the prohibition in America, when people used them as an alcohol substitute. The smell actually works with the top notes on champagne really well," he says, offering me a sniff. And the effect? "They're just lethal; they seemed to affect everyone's recall of nouns. People kept on saying 'that thingy or that thingy', which was all quite weird at breakfast."

A soupçon of anaesthetic gas aside, it's difficult not to be dizzied by the work of these self-styled "architectural foodsmiths", giving Heston Blumenthal a run for the money in the fantasist stakes. From vapourised gin and tonics to scratch-and-sniff cinema screenings, the pair work at the crossroads between food, design, science, history and pranksterdom. "All of our work springs out of a love of making food, but it's also about working beyond food to give people a total immersive experience," Bompas, 26, explains. "Ideally, when they come away, they won't be able to describe what's happened to them."

It all started with a wobble: jelly, the former dessert favourite, whose renaissance they have championed in their capacity as the nation's top – or should that be only? – Jellymongers. The old Etonian school friends founded Jellymongers two years ago after a gelatinous epiphany, when they observed wowed reactions to a traditionally moulded blackcurrant number they had made for a dinner party. "People know about jelly for the wrong reasons; they associate it with children's parties and the instant stuff, but in actual fact it has this incredible history," says Parr, also 25. "It used to be one of the most magnificent creations," concurs Bompas. "At Victorian dinners, they wouldn't put flowers on the table; you'd set out jellies throughout the entire meal instead."

The plan was to use antique copper moulds, until they realised they couldn't afford them – a blessing in disguise, as it was then that Parr realised he could call on the skills he'd acquired as a trainee architect to make their own, creating 3-D computer models of any given structure and then forming plastic moulds from them. Subsequently, they have produced jelly replicas of everything from St Paul's Cathedral to a nuclear submarine and a topographical map of America, while clients have included Sir Richard Rogers, Mark Ronson, and indeed, Blumenthal himself, who they collaborated with on the Channel 4 show Heston's Victorian Feast.

And for that extra dash of awesomeness? They can make them glow in the dark, by adding the fluorescent chemical quinine contained in tonic water, or light them up internally by shooting LEDs through Perspex tubes. "It appears that jelly is quite a restrictive medium, but the more you do, the more you realise how versatile it is. We've made tens of thousands of them but we're still learning new things," says Parr.

Thankfully, for all such theatrics, their creations taste as good as they look; the plum- and rose-flavoured version I sample is every bit as silky and palate-cleansing as my mother's creations were lurid and teeth-dissolving, with the sweet, jammy plums given delicate piquancy by the booze. So what's the secret? It's all in the wobble, apparently. "If you have very strong jelly that doesn't wobble at all, when you put it in your mouth you're going to have to chew on it, but if you have a really wobbly jelly, you know it's going to melt straight away," explains Bompas. "And people enjoy the sight of ' jellies wobbling. It has that element of British seaside humour to it – "the wobbly bits" – which is always good fun."

Smutty perhaps, but their jelly has also proved adaptable to more high-brow tastes: they recently put on a glow-in-the-dark funeral-themed jelly installation at the San Francisco Museum of Modern Art. Did they ever imagine this frivolous edible treat would be considered quite so edifying? "It wasn't so different from the stuff we do normally, but people saw it in a different light. Anything in an art gallery's taken a lot more seriously, and in America people take things a lot more seriously anyway," notes Parr wryly.

But whether they are arch provocateurs or overgrown schoolboys, a taste for the spectacular, which began with jelly, has transmuted into full-blown culinary events and installations. Take their dinner to celebrate the 100th anniversary of the birth of Futurism, which offered treats such as "black olives, fennel hearts and kumquats presented with corresponding flags of sandpaper, silk and velvet" on a fake aeroplane. Or their recent Black Banquet, a gothic eight-course meal of black food with the aforementioned leeches serving as the most active of table decorations.

Most outlandish of all, perhaps, was April's walk-in cocktail: sponsored by the gin company Hendrick's, they had punters donning boilersuits to mingle amid a gin-and-tonic mist, accompanied by a soundtrack of splashing and tinkling for added inside-the-glass authenticity. Despite issuing an enjoinder to "breathe responsibly", it was a nerve-wracking operation, admits Bompas. "We worked with doctors who deal with absorption rates through inhalation, and did a complex series of calculations based on the ABV of gin, the alcohol output rate, the number of people in the room, the throughput of air volume, and the time they were in there. Thankfully, we managed to calibrate it in such a way that they didn't get really trashed."

Still, it hasn't stopped the Jellymongers upping the ante for their next cocktail-related scheme, a giant "architectural" punch bowl, backed by Cognac brand Courvoisier. Installed in the vast London mansion of 33 Portland Place W1, it will be unveiled next month, dosed, as is standard for the duo, with a shot of historical precedent. "We heard an amazing story about [the 17th-century admiral] Edward Russell, who hosted a six-day party in which he flooded a fountain with cocktail and had a small boy row back and forth across it serving people. We just thought, 'Bloody hell, what would we need to do to create something like that?'" says Bompas.

Following an online competition asking the public to devise a super-sized punch recipe, complete with garnishes and serving suggestion, the contents will be selected from a shortlist of five. These range from "a gilded oasis of alcohol" flavoured with chilli and beetroot and inspired by the Russian Revolution, to a punch using the system of proportions espoused by the legendary architect Le Corbusier to mix drinks. First up, though, there has been the small matter of designing a bowl, for which they've called on the help of engineering giant Arup. "If we get it wrong, the whole building could collapse... but it won't," Bompas says cheerily.

Mass destruction notwithstanding, it seems they may be carving themselves a lucrative gastronomic niche. Daft as they are, such projects can generate reams of international press coverage for partners such as Courvoisier, and with the ever-increasing buzz surrounding the concept of "experiential" marketing, one can expect more brands to come knocking at their door. On the jelly front, meanwhile, next year will see the publication of their first cookbook, as well as their attempt to break the world record for the largest jelly, which currently stands at one metre tall by seven metres wide. "The base-plate will have to lock into the mould," Bompas explains, "and then we might have pipes running hot and cold water through it: the cold water to make it gel, and the hot so it melts around the outside so you can lift [the mould] off. Also, as the jelly is so big, we'll have to make an internal structure..."

Even as they lose me at this conversational juncture, physics dunce that I am, the evident seriousness with which they pursue their silliness is delightful. "We just want to keep on doing new things. Upping the scale is important," says Parr. "We do want to win the Turner Prize," pipes in Bompas. "I've got eight ideas on the go. I think would we could tear it apart!" The mind boggles – but you wouldn't bet against it. n

The Courvoisier Architectural Punchbowl is at 33 Portland Place, London W1 from 8-10 December. Tickets available from www.jellymongers.co.uk. To contact Bompas and Parr, email info@jellymongers.co.uk. Bespoke jellies from £300