So it's true – only half of us can pick out an expensive wine from a cut-price alternative on taste alone.

That was the finding of Professor Richard Wiseman, the psychologist and guest director at this year’s Edinburgh Science Festival, who organised a blind tasting two weeks ago. The stunt must have thrilled the festival organisers for, if nothing else, it generated a mountain of free publicity.

“I’ve been doing these sort of high-profile experiments for quite a long time, so I have some idea of the sort that catch people’s attention,” he told me, adding that he was “delighted that it made the Wall Street Journal and Time magazine” -- plus the Times of India, the BBC and, of course, The Herald.

‘“Brits can’t tell plonk from premium” crowed one foreign headline and with some justification. Last March the chef Heston Blumenthal offered the well-paid suits in London’s Canary Wharf a choice of sparkling wines and asked them to say which was champagne. Most picked the glass of Blue Nun frothed up in a Soda Stream. So much for City boys and their discerning palates.

Of course the media love these stories -- it is one in the eye for wine snobs and a small victory for the common man. Or as one newspaper put it “spending more than £5 on a bottle of wine is a waste of time”. But is this because the wines themselves cannot justify their price or is it because many of us struggle to recognise their quality?

At the science festival, the worst result was for Bordeaux where the choice was between a £3.49 claret and some grand-looking château at £15.99. Only 39% correctly guessed which was the more expensive, startling when you consider the value of the actual wine in the bottle. In the cheaper version, once you have stripped out tax and the retailer’s margin, it would have been pence and a tiny fraction of the more expensive one.

“The wine industry has come up with all kinds of objections, but I don’t find any of them particularly convincing,” says Professor Wiseman, and I tend to agree. The idea the fancy-pants Bordeaux could not show its true complexity and finesse because it was too young and needed years in a cellar sounds disingenuous.

Yet if there is no point in spending more than a fiver on a bottle of wine, I may as well pack up and go home. To me, however, the Edinburgh tasting underlines the need for more wine knowledge and more columns like this. Having said that, the old adage that you get what you pay for is flawed when it comes to wine -- just look at those supermarket bottles that dance a promotional jig between £9.99 and £4.99. At full price they are a rip-off.

Knowing that Prof Wiseman bought everything from the Co-Op, maybe I should recreate his tasting. If someone else poured, I could test myself. Fingers crossed I score more than 50%.