Why a wine's taste can be in the glass

What wine snobs have been telling you for years really is true: the shape of a glass does make a difference to how wine tastes. The reason is that some wine glasses allow more of the subtle chemical reactions with air because a greater surface is exposed to it.

Kari Russell, a food science student at the University of Tennessee at Knoxville, studied merlot wine, investigating if the claims of the people at the local wine group were true. Could the glass really make a difference to the taste?

Amy Wislocki, editor of the leading wine magazine Decanter, said: "It's no secret to people in the wine trade that wine tastes different in different glasses. My personal bane is those really shallow Paris goblets you get in pubs and some restaurants. Even restaurants which pride themselves on having good wine lists have these awful wine glasses."

George Riedel, an Austrian glass-maker, pioneered the concept of choosing the right wine-glass shape to match a particular grape variety. His company, Riedel Crystal, produces a host of different glasses for different wines.

But is it based on any reasoning? Ms Russell poured samples of the wine into a champagne flute, a Martini glass, and a wide bordeaux glass and measured their concentrations of phenols, the organic compounds that act as antioxidants, thought to give red wine some health benefits.

After pouring, the concentration of a phenolic compound called gallic acid increased, probably because the act of pouring triggers reactions that convert the gallic tannins that give red wine its colour and taste into the acid form.

Between 10 and 20 minutes later, the concentration of gallic acid was still high in the flute and the Martini glass. But it had fallen in the bordeaux glass, New Scientist magazine reports today. The bordeaux glass has a larger surface area of the wine exposed to the air than the other two. Oxygen in the air turns gallic acid into another compound, called catechin- gallate ester – and esters are the chemicals essential to giving wine a taste. The catechin-gallate ester in particular makes the wine taste dry.