Who is Oz Clarke? Ridiculous question: everyone knows Oz Clarke. Television, wine, larks: that’s Oz. Lots of books, too, with Oz’s friendly buzzard face all over the front of them, sniffing, smiling, waving, his freckled cranium gleaming and his neat raptor’s nose hooked inquisitively into the glass. Tesco’s website tells me that Oz Clarke is “one of the world’s leading wine experts, with a no-nonsense approach to wine. This makes the Oz Clarke CS1 electric corkscrew a necessity for all wine lovers.” You may, perhaps, question the logic, but you can’t fault the fame. Anyone whose name can help sell an item as superfluous as an electric corkscrew is authentic public property.

I’ve known Oz for almost twenty years, worked with him briefly on a live radio show, landed with him in a small aeroplane on a dirt strip in southern Portugal, heard him in confessional mode over a bottle of Cape Mentelle at Shampers in Kingly St, and listened to his often hilarious asides at 100 or more wine tastings. We give each other a hug when we meet … but I’m still not sure that I really know him. One of his oldest friends is the wine writer Charles Metcalfe who, Oz claims, “taught me all about wine” when they were at Oxford together in the late 60s. Does Charles really know Oz? “I know him pretty well. Really know is difficult. He’s actually quite shy. He tends to use the bonhomie to shield himself from deeper enquiry.”

Anyway, here are some facts. Oz’s dad was a chest physician, and his mum a nursing sister; Oz (Robert on his birth certificate) and his brother and sister grew up near Canterbury. He became head chorister at the Cathedral Choir School, and later won a choral scholarship to the King’s School; thence to Oxford (Pembroke: Theology and Psychology) where he joined the wine society (as an inexpensive way of pursuing girls, he claims) and acted. Acted well enough to make a career of it after Oxford, playing all the men in 'The Mitford Girls' and singing his way through 'Evita' as General Peron, as well as playing Hood #4 -- with unheralded subtlety and psychological insight -- in the 1978 film of 'Superman'. He never, though, lost his interest in wine, and celebrity made that publically apparent. Oz was, thus, called to captain a series of amateur tasting teams put up by The Evening Standard against international competition; they duly walloped national teams from France, Germany and America. By 1984, he was the wine writer for the Sunday Express magazine, and later for the Daily Telegraph. His long-running double act with Jilly Goolden on BBC2’s ‘Food and Drink’ became a kind of national institution, bringing the pleasures of the extravagant sensual metaphor to millions; Oz is now publically paired with autophile James May on 'Oz and James’s Big Wine Adventure' (they’re setting off round Britain soon).

When I think about Oz, though, those aren’t the things I want to tell people. I want to tell them, first of all, that Oz has one of the best brains I’ve ever come across, in any field. In that sense, his public persona does him no favours. He’s quicker than small-arms fire; he’s funny; and he forgets nothing. I’m not just talking about wine, but about all the things which tumble into people’s ears down the years, and which most of us haplessly lose soon afterwards. Like Funes the Memorious, the Jorge Luis Borges character doomed to forget nothing, Oz is weighed down with decades of undisposable events, insights and experiences, and even the briefest of conversations with him opens a storeroom or two and before you know it, half-an-hour of lushly detailed recollection has tumbled out. He declined the offer of a luxury when he was on ‘Desert Island Discs’, telling Sue Lawley he had ‘his memories’ instead. Given Oz’s memories, that probably counts as cheating.

I’ve never heard Oz speak ill of anyone: admirable. He’s hugely professional, bashing away at things until perfection feels near. He’s legendary at wine tastings, for example, for being the last to leave, not wishing to leave any bottle unessayed. Cheeky readers, of course, might suggest a reason other than professionalism for this – but, cheeky ones, you’d be wrong. I’ve seen Oz appear to be tipsy -- but never quite believed it. It was almost as if the actor was putting it on. You’d ask him a question, and realise that the brain was still razor-sharp underneath, and that he remembered the third Sauvignon of the eight on show better than you did.

What about his famous tasting abilities? Oz in action is indeed an impressive sight, though he sometimes makes me wonder what exactly we mean by ‘tasting ability’. In the unique Oz Clarke brain, it is the synthesis between sensory experience, sensory recall and verbal articulacy which is unparalleled. Give him a glass of wine, and out comes a verbal torrent; it’s like watching a hot-air balloon lift off, filling the sky with brightly coloured canvas. Once it’s gone, you might find yourself rubbing your eyes and saying ‘Did that really happen? Or was it a dream?’ But all the great tasters I know are great in a different way. The Oz way wins friends and influences people.

He has failings, of course. He’s hard to get hold of and magnificently technophobic (no email, no mobile, reputed not to be able to type). I love the idea of the ‘Oz Clarke CS1 electric corkscrew’ -- since I suspect he’d be in intensive care within minutes of trying to use it himself. He talks so well and so fluently that some claim he’s interested only in the sound of his own (admittedly beautiful) creamy bass voice. His friends sometimes think he hasn’t always been the best steward of his own career, allowing others to turn him into more of a brand than he deserved and thereby obscure his magnificent gifts (which include fine writing in accessible, stream-of-consciousness style). Taken all in all, though, he is a prodigious democratiser, a national treasure – and a great bloke, too. So far as I know.