"We love you English because you like your wine old," smirked the impeccably coiffed Bordeaux producer. "So you take the wine we can't sell to anyone else because they think it's past its sell-by date." Her nudge and a wink around the lunch table suggested I must be the dumbest wine writer on earth for condoning the British taste for an ageing tipple. For sure, fine wine often needs some age. And in the case of everyday wines, we are no longer quite so thrilled with the smells of undergrowth and antimacassars. Thanks to the New World, we have, in fact, developed a taste for fresh and generously fruity wines. But as not all wine is made to age gracefully how do we know when it's becoming past its best?

Recently I had two letters from readers about the shelf life of wines and wondering if there was a case for putting the sell-by date on the bottle. Both are concerned with the possible ill effects of bright, warm lighting and too much time spent on the shelf. "Fino sherries suffer, and certainly many good reds when they're kept somewhere warmer than room temperature," commented one reader. For the same reason, the other said that she didn't buy wines from supermarkets "except for impulse buys and reliable recommendations".

One man addressing this issue is Nick Dymoke-Marr, a former Asda buyer who now runs Orbital Wines. "There's a lot of old wine about and the surplus is often sold on promotion, with older vintages lurking on the shelves behind younger ones," he says. When he decided to put a sell-by date on the back label of his Stormhoek range from South Africa, adding screwcaps to boot, he got three responses from supermarkets: "One: we don't get it. Two: could be interesting. Three: yes, we'll give it a go." Waitrose is one that's given the thumbs up to his Ultimate Freshness concept, agreeing: "On many of our own-label wines we state that the wine is best drunk, for example, within a year. Although not required, our own-label bag-in-box wines have best-before dates on them. We think it would be good to have some guidance on the label."

A number of supermarkets now have best-before codes on the more "sensitive" products. Sainsbury's has it on its three-litre wine boxes and some fino sherry. According to Sainsbury's technical boffin: "The lives given to such products are typically nine months to a year, depending upon the style of wine." Sainsbury's has also improved air circulation, and brought in new low-output halogen lights positioned away from the bottles to minimise any heating effect. Tesco too has date-coded some of its wine products, claiming "we do everything possible to minimise risk to product quality in store, from the design of bespoke lighting, to bottle colour and label design".

Behind this concern for us consumers, let's not forget that wines today, like nappies and Mars bars, are regarded like any other "fast-moving consumer goods". Rapid turnover is what matters. As one of Tesco's major wine suppliers, Bibendum has full access to the supermarket's database - it can see at a glance which of its wines need replacing, store by store, day by day. "It's basically as if the supermarket is renting you shelf space," says director Simon Farr. "Being a supplier now is a package and it's not good enough any more to say, 'My Sancerre is better than yours'." So, as long as the customers' and the supermarkets' interests coincide, why not have sell-by dates on everyday wines? Maybe Mr Dymoke-Marr can patent that one and make his millions.