Bubbly poured into a long narrow flute provides more of a nose-tingle than when served in a wide and shallow "coupe". The reason is that much higher levels of carbon dioxide, released by bubbles in the glass, collect at the top of a flute.

Carbon dioxide irritates sensory nerves in the nose, giving rise to the well known tingling sensation that accompanies drinking champagne.

Scientists used sophisticated gas-analysis technology to test the effect of either pouring champagne into a flute or a coupe. Infrared imaging was also employed to visualise gas escaping from the champagne surface.

The effect of bubbles is an essential part of the champagne drinkers experience, the French researchers stressed in the online journal Public Library of Science ONE.

Dr Gerard Liger-Belair and colleagues, from the University of Reims, wrote: "From the consumer point of view, the role of bubbling is indeed essential in champagne, in sparkling wines, and even in any other carbonated beverage.

"Without bubbles, champagne would be unrecognisable, beers and sodas would be flat. However, the role of effervescence is suspected to go far beyond the solely aesthetical point of view."

A standard 75 centilitre bottle of champagne typically holds around nine grams of dissolved carbon dioxide. Released into the air, this generates around five litres of gas under normal conditions of temperature and pressure. Carbon dioxide (CO2) is a "potent irritant" of the nasal cavity, the researchers pointed out.

Concentrations of gaseous CO2 above the champagne surface were measured for the first 15 minutes after pouring into each type of glass. The tests showed that throughout this time, levels of the gas close to the edge of the flute were two to three times higher than those reached above the coupe.

Surprisingly, lowering temperature did not affect the level of carbon dioxide above the glass, said the scientists. They wrote: "Those analytical results are self-consistent with sensory analysis of champagne and sparkling wines, since it is generally accepted that the smell of champagne, and especially its first nose, is always more irritating.. when champagne is served into a flute than when it is served into a coupe."