Why smaller bubbles might not be the sign of a better champagne

Findings suggested that the 'small bubbles were the worst in terms of aroma release.' Photo / Getty Images

It is often said the smaller the bubbles in a glass of champagne, the better.

But research suggests this widely held belief might not be true. Scientists based in the heart of France's Champagne-Ardenne region have found larger bubbles may actually improve the taste of a sparkling wine.

They found that bigger bubbles, around 3.4mm across, increase the release of droplets that carry champagne's aroma and flavour into the air, driving them into the drinker's nose when they take a sip.

Traditionally wine connoisseurs use bubble size as a marker of quality - with larger bubbles in cheap sparkling wines such as Cava.

But lead researcher Professor Gérard Liger-Belair, a chemical physicist at the University of Reims, said his findings undermine the idea that this equates to better taste, adding: "Small bubbles were the worst in terms of aroma release."

Around a million bubbles form in the average glass of champagne, the professor said. They form due to dissolved carbon dioxide, which enters the wine during a fermentation process. When the bottle is opened, this gas is released, often explosively. The remaining gas then gradually bubbles to the surface.

These bubbles form a 'raft' on the surface and then burst, releasing a cloud of tiny droplets. Professor Liger-Belair said bubble size in champagne and sparkling wine can vary from between 0.4mm and 4mm across.

Using high-speed photography, Professor Liger-Belair and his team, who published their findings in the European Physical Journal Special Topics, found bubbles with a diameter of 3.4mm released the most droplets. They also showed the bubbles form a regular hexagonal pattern on the surface.

The team have previously shown chilling champagne can lower the amount of alcohol carried in each bubble. This can prevent more delicate flavours from being overpowered.