Definition: Effervescence

Foam and bubbles are enjoyed with the ears, eyes, nose and mouth. All the senses are involved. It's a celebration! The same wine, deprived of its foam and bubbles, would lose all its appeal for the consumer. Indeed, champagne without foam or bubbles would reveal the weakness of a grape must produced in a region where it struggles to reach full maturity.

That is why, since 1989, the Moët & Chandon research laboratory in Epernay in the Marne region has been conducting a programme of studies on foam and bubbles. Initially set up in collaboration with the beer manufacturer Heineken, Moët & Chandon is now continuing this programme independently.

The primary objective is to analyse all the parameters that cause foam to form and disappear within a given time. Of course, bubbles cause foam to form as soon as the bottle is opened. The gas dissolved in the wine, at a pressure of up to five atmospheres, is just waiting to be released. The foam lasts only a few seconds in sparkling wines, unlike beer, where it lasts for a long time. In champagne, after the foam has settled, a string of fine bubbles forms inside the glass and lasts for several minutes. Researchers at the Moët & Chandon laboratories have analysed, quantified and formulated equations for all the parameters of this complex and dynamic phenomenon. Using cameras to track the evolution of these bubbles, they have identified the enemies of foam and bubbles in champagne glasses. Here are their main conclusions:

The behaviour of the foam depends primarily on the glass and not on the champagne. It is not the chemical composition of the glass but its surface condition that is important. When viewed under a microscope, the glass surface is not smooth. These imperceptible irregularities are the source of the gas bubbles. As proof, there are sparkling wine flutes whose inner base is slightly frosted in an almost invisible spot. This causes a string of bubbles to spontaneously form at the very bottom of the glass. The main enemy of sparkling wine foam is dishwasher rinse aid. It contributes to the creation of abundant, large-cell foam. As proof, foam formation is much more abundant when the glass is first filled, to the point that it has to be done in several stages. Once the inside of the bowl has been wet, foam formation is significantly reduced with subsequent fillings and the glasses fill easily. As a result, a beautiful foam, followed by a string of fine, persistent bubbles, will form in a flute that has been washed by hand, carefully rinsed and dried with a high-quality cloth. Another detail is that lipstick and grease weaken the bubbles.

Finally, the idea of placing a small silver mocha spoon in the neck of an empty champagne bottle to preserve its gas is pure fiction and has no basis in fact (study by the Comité Interprofessionnel du Vin de Champagne, CIVC).