Oyster shucking: Behind the scenes at the Tabasco British Oyster Opening Championship

Woe betide the shucker who has not severed the oyster from its shell

Contest winner Fredrik Lindfors at work. Oysters must be presented with briny flesh (Ben Fisher)

It is a peculiar sight: to walk into a restaurant and find four grown men, craned forward over platters of oysters, examining them as if they were diamonds. And even stranger to find this outpost of the Wright Brothers fish restaurant so full of "well-refreshed" patrons at 4pm on a wet Wednesday.

Do these people not have jobs? Well, as it happens they do. They are a bunch of shuckers, and this is a competition to find the best of them.

For 23 years, this event, the sonorously named Tabasco British Oyster Opening Championship, has been testing the skills and mettle of the nation's mollusc masters (its longevity, or perhaps the fact that the Bloody Marys flow like the River Tiber, may explain the number of people there).

Eleven contestants – one of whose biography on the programme describes his favourite way to eat oysters as "like I like my women: naked" – have travelled from all over to open 30 oysters and then ring a hand bell in as quick a time as is humanly possible. The thing is, they can't just smash the things and sling them down on the tray, as you or I might do. Each oyster is minutely examined – hence the peering conclave taking place when I arrive – to ensure it is of a standard that any self-respecting restaurateur would serve to a mollusc-loving punter.

Woe betide the shucker who has not severed the oyster from its shell, or who serves it with grit on the flesh or with blood inside, or, indeed, not presented upright and with its briny flesh unmolested by the shucking blade. These misdemeanours are punished with extra seconds being added on to their time. It is these strict rules that lead most of the competitors to shun the protective gloves that any sane, or inexperienced, person would use to protect their finger ends. Here, though, a finger-end is as of nothing compared to a slow time and, as Ben Slater from The Bloody Oyster says, "no pain, no gain".

Experience counts for all in this contest, as indeed it does in most culinary endeavours. So it is perhaps not the greatest surprise when Fredrik Lindfors, of The Fish Shop in west London, is laureled as the fastest shucker in Britain, with a time of three minutes and 55 seconds, and will be off to the world championships in Galway. Lindfors, who has a pint of Guinness to steady his nerves, has won the contest seven times now, so he seemed the sensible person to ask about technique.

He advises that "all oysters are different", but to open them successfully, and with verve, you have to identify the hinge. Identify it and "then avoid it", he says, with the weather-worn care of a man who has been shucking since 1997. "Go a little to the side of the hinge and just wiggle it open – and you will feel it giving," he says.

I try this procedure myself later in the week and can confirm that it takes me some time longer than Lindfors' own 7.83 seconds, which is doubly frustrating, since Lindfors "never practices". What is his favourite way of eating oysters, I ask him, as he's about to slurp a Loch Ryan native. "Deep fried," he says. How come? "I find I get on with them better," he says coolly. Not just the fastest shucker in town, then – but the coolest too.