IT is widely recognised that the smell of wine plays as big a role in unlocking a vintage’s complex flavours as tasting.

But researchers now say a wine’s taste can vary dramatically depending on the size of the sip taken. While taking a small slurp can produce grassy, woody and even almond flavours in a white wine, a larger gulp can transform it into a blast of citrus and flowers.

The reason, the scientists say, is because wine releases different quantities of smelly chemicals, known as volatiles, in the mouth depending on the volume of liquid tipped in. Their research also helps to explain why wine so often fails to taste the same as it smells.

Usually flavour is strongly influenced by smell, as the nose plays a major role in providing the subtle ways we experience food beyond the five basic tastes that our tongues detect.

While that remains the case, the researchers found that human saliva also fundamentally changes the way volatiles are released from wine, producing quite different flavours in our mouths than we would expect from smelling or ‘nosing’ the wine.

The findings have raised the prospect of critics and ordinary drinkers changing the way they drink wine.

Marcia Waters, a member of the Institute of Masters of Wine and an expert on sensory training, said: “This work may well have implications on how wine tasting can be conducted. I think many tasters have just found a style of tasting that suits them without really considering the particular compounds they are trying to detect.”

But Victoria Moore, The Telegraph’s wine critic, said it would be very hard for drinkers to regulate the amount they took with each sip accurately for it to make any meaningful difference.

“Everything we do changes the way we taste the wine, whether it’s the type of glass we use or the amount we pour into the glass. But sniffing remains one of the most important ways we detect flavours,” she said. “It’s hard enough to persuade people not to fill their glasses to the top, because you lose the wine’s aroma, which produces so much of the taste, never mind them remembering to alter the size of their sips.”

One of the researchers, Dr Paola Piombino, from the University of Naples Federico II in Italy, said their findings could prove useful to help beginners better identify wines.

“Small sips could improve the detection of a molecule called damascenone – involved in the varietal character of chardonnay, semillon and sauvignon blanc wines – enhancing the distinctiveness and recognisability of these wines among non-expert consumers.

“Large sips could favour the detection of a distinctive kerosene note characteristic of the renowned white wines riesling and gewurztraminer after ageing.”

The new research suggests some wine critics may need to take greater care when tasting wine to ensure they take different-sized gulps.

It could also mean consumers could enjoy far more sensory pleasure from their wine simply by varying the size of their sips.

The researchers recommend small sips to taste baked apple, apple pie and floral flavours associated with chardonnay, semillon and sauvignon blanc varieties, while larger sips detect the flavour of berries, cherries, grapefruit and honey.

The researchers, whose work is published in the journal Food Research International, analysed 22 volatile compounds emitted by two Italian white Falanghina wines.

They designed a model to mimic the human mouth, capable of holding an average of 100ml, and used a technique known as high resolution gas chromatography-mass spectrometry to analyse the volatile chemicals released by samples of either 30ml (a small mouthful) or 40ml (a large gulp).

They also added saliva taken from 13 non-smoking male volunteers to half of the samples.

They found the aromatic fingerprint, or bouquet, of the wines changed dramatically when the volume was increased, while adding saliva further transformed it.

They say that this occurs because the most volatile molecules released from the wine quickly fill the smaller “air pocket” in the mouth from a larger sip, while in a smaller sip the less volatile compounds have more time to escape.

For example, levels of a compound called ethyl decanoate, which gives a flowery and sometimes soapy taste, increased in larger sips. A chemical responsible for sweet honey and melon flavours, 2-phenylethyl acetate, decreased in the larger sip volume but when saliva was added was higher in the larger sip volume.

The Sunday Telegraph, London