Like your first slippery oyster or hit of white truffle, your first true American barbecue will always stay with you. Mine was at a simple Formica-tabled joint on West 23rd St in New York called Righteous Urban BBQ – Rub for short – back in the middle of the last decade. I remember looking up from my plastic tray of sweet-sticky St Louis style ribs, with a side of pulled pork and a few meaty rib tips, to see the TV chef Mario Batali sitting across the room. I had interviewed him the day before but had not mentioned I was coming here. Now he summoned me over and we sat chatting over our trays of long cooked pork. I told him that I had always wanted to try real US barbecue, and that it was all as good as I'd hoped: that glorious calculus of meat and crisped fat and sauce and smoke was making me very happy indeed. He nodded slowly. "My friend," he said. "You have come to the right place."

It says much for the cult of serious barbecue that lots of people will now be shouting at the page: no you hadn't. You were in entirely the wrong place. It can't be the real thing on Manhattan Island. Real barbecue has to be eaten next to a smoking pit being fretted over by an old guy called Charcoal Joe or Sauceman Mackenzie, off a dusty road in Texas. It has to be eaten at one of the huge competitions such as the American Royal in Kansas City or the Jack Daniel's Invitational in Lynchburg, Tennessee, where big men in denim dungarees smoke and grill tons of prime pig and cow across a weekend. And yes, they would have a point. It is country food, not city food, though it can be found there. It has its own subculture and code; but all you really need to know is this. It has almost nothing in common with the shameful things the British do to sausages in seven minutes flat any weekend the sun shows itself. American barbecue is not about fire. It is about indirect heat. It is about smoke. It is about spice rubs and sauces made to secret recipes applied and applied again. Most of all it is about slow. Cooking times are measured in hours and sometimes in days, which results in flavour burrowing deep into tender flesh.

The good news is that I no longer need to go to West 23rd to eat it, for the cult has found disciples in Britain. The small chain Bodeans does a creditable job of knocking out proper pulled pork and ribs (and rather good beef ribs too). There are the Pitt Cue boys, Tom Adams and Jamie Berger, who first plied their trade last summer from a street food van on the banks of the Thames and who now have a permanent site behind Carnaby Street. Jamie Oliver has backed US barbecue star Adam Perry Lang at Barbecoa in the City, Anthony Flinn has opened a rib place in Leeds and the Rib Man is a regular at street food conventions. And in Brighton there's the BBQ Shack at the grungy World's End pub, run by British barbecue champion John Critchley. The summer calendar is also full of barbecue contests including Grillstock in Bristol (30 June - 1 July) or the Big BBQ Festival on 23 June at Canvey Island in Essex. It has a top prize of £10,000, the largest ever in the UK. When the big money piles in, you know it's getting serious.

The appeal of US barbecue, says Tom Adams of Pitt Cue, is simple: "It's hands on and it's dirty. There's an intensity to it that you don't come across in food very often." Adams grew up in Hampshire where he built his own smoker on the banks of the local river to cure the local fishermen's catch. "Soon I was doing pork too." Then he met Jamie Berger, whose mother is from the southern US state of Georgia. "That's when it all came together. It's a satisfying way to cook. You put the meat into the smoker as one thing and 12 hours later it comes out as something else."

Can anyone do this? Can we all become barbecue pit masters at home? Yes, says Adam Perry Lang of Barbecoa. He is not a classic barbecue boy. He was a restaurant chef in New York who tired of the controlling nature of the kitchens he worked in. "When I first started cooking with fire and smoke it was like meeting this unruly thing." And yes, he says, people will lecture you on what's right and what's wrong. "A lot of these guys from specific areas of America are very loyal to them. But it's more political than anything else." Don't be hidebound by all that, he says. It hasn't hurt Perry Lang; his pulled pork – long and slow cooked shoulder, properly sauced – has won the Royal. "What matters when cooking low and slow is consistency of temperature. You need to cook at about 120C. And you need to keep your nerve. People worry it's taking too long. It isn't."

In short it is one for the nerds. It's about multiple processes, endless temperature checks, decisions about types of wood to use, marinades to make, rubs to grind. Which probably explains why it is mostly a male pursuit. The day I first came across John Critchley, at a barbecue competition, almost all of those taking part were burly blokes. There were beards. Lots of them. But Critchley, a big melon-bellied chap with a broad Wigan accent, stood out. He trained as a restaurant chef in the 70s, before heading off across America to DJ with 90s ravers Spiral Tribe. Which was how he found himself in Texas without a job. He went to work in a restaurant and that's where he learned about barbecue.

I meet him at the World's End, which is about as close as we can come in this country to a roadside shack. He tells me he's been up since 3am to get that day's ribs sorted. I express disbelief. "That's what it takes," he says. Outside the kitchen is one of the professional smokers, a big shiny metal cupboard called the Fast Eddie by Cookshack, which can take 45kg of meat. It automatically feeds wood pellets into the oven to keep the level of smoke even and constantly monitors temperature. It costs about £5,000. I ask if you need a piece of kit like this to do the job properly. "No, not at all. It just helps when you're doing large volume. I do about 120kg of ribs a week, 120kg of pork shoulders and 90kg of brisket." That amounts to a third of a tonne of meat every seven days. "That's why I need one of these. But it's all very doable at home. You just need patience."

He unwraps some of his brisket from its foil overcoat. It has been cooking since 5pm the previous day, has a deep rub, and a pink tinge from the smoke. I pull at the meat, and slip away quietly to my happy place. He's also done me ribs, big spares rather than baby backs, glazed with his sauce. Plus there's a dipping sauce made with tinned peaches and chillies, all blitzed together with a sauce base. I suggest that doesn't sound very conventional. "I like to experiment. But I think you should know the rules before you break them."

And there are rules. Critchley takes me through the process for doing his ribs at home. Barbecue takes time and seriousness. There aren't short cuts. A sausage blackened over burning firelighters on a rainy English summer's day until it tastes only of petrol is a short cut. This is the real thing. So have a good long read of our recipes, gather your equipment, phone your butcher. And clear a weekend in the diary. Trust me: it's worth it.