You can't have too much of a good thing when it comes to wine. Or can you?

You can't have too much of a good thing when it comes to wine. Or can you? I was contentedly sipping a glass of 2001 Glen Carlou Reserve Chardonnay recently. It had all the yummy attributes of a terrific wine, lots of flavour, plenty of creamy richness, and lashings of spicy oak. So far so good. But after all that good work, something palled and burnt the back of my throat. Enough was enough. Sorry Glen Carlou for singling you out, because your chardonnay is by no means the worst or only offender in what's becoming a growing phenomenon. Welcome to the not-so-wonderful world of the one-glass wonder.

The one-glass wonder is a wine that comes on to you, as burgundian winemaker Alix de Montille succinctly put it in the wine documentary, Mondovino, "like a whore". It looks good, smells good, with vanilla, spice and honey and all that, and, initially at least, it tastes good. It may be an obvious wine like an oversweet Alsace gewürztraminer but more often than not it's a New World chardonnay. If it's red and smells of coconut, and chocolate and tastes of strawberry or blackberry jam, it could be a California zinfandel, an Aussie shiraz or a South African merlot. What it amounts to is a concentrated, powerful red in whose sweet embrace lies the beginning of its, and our, undoing. A one-glass wonder is ultimately a letdown because too much alcohol, too much sweetness or too much oak, smack you in the mouth like Mike Tyson.

The one-glass wonder has been encouraged in a number of ways. First, wine competitions give a boost to trophy wines that outmuscle skinnier competitors. Then there's the American critic Robert Parker, whose championing of wines in the superripe mode is slavishly supported by producers looking to score marks. Above all, they're the pay-off for all those reliable, affordable New World brands. They're the result of the growing trend towards picking grapes riper, and the added alcohol that results from extra "hang time". In what California's Randall Graham calls "thermically overachieving" climates, wonder grapes with high sugar contents have to be picked before they are fully ripe or when the potential alcohol reaches monster levels of 16 or 17 per cent.

Techies have come up with several solutions. First up is the spinning cone, first developed in Germany for the separation of heavy water isotopes. It also reduces alcohol. More than 100 California wineries are estimated to have tried it, thanks to the local company ConeTech. Many winemakers agree with Daryl Groom of Geyser Peak, who says, "We don't want to make alcoholic, unbalanced wine. Any tool that can produce a better wine for the consumer is a good thing." Then there's Vinovation, which reduces the alcohol by a process known as reverse osmosis. Finally - and yes, it's true - the latest practice condoned by California is the addition of water to wine, or "humidification", re-hydrating the dying berry.

One of the world's top experts, Dr Richard Smart, is not alone in believing that if vines are in balance, fruit should ripen sufficiently well to produce a wine that refreshes. Which is, after all, wine's job. This is one of the big challenges facing mainly New World wine producers over the coming decade: how to grow grapes in such a way as to achieve optimum ripeness at harvest without resorting to fire-fighting techniques. Maybe there is one hidden benefit, however, in the one-glass wonder. Where you have eight or more people, pour each a small glass. Sometimes, one can be quite enough.