Chances are good that during the holiday season, you found yourself holding a glass of champagne. If the festivities were flagging, a question may have crossed your mind: What causes those delightful little bubbles that tickle your nose? In Uncorked: The Science of Champagne
(Princeton University Press; 152 pages), Gérard Liger-Belair answers this and other questions that have occupied the wine world since the night French monk Dom Pérignon invented champagne in the late 17th century. Liger-Belair, an associate professor of physical sciences at the University of Reims Champagne-Ardenne, used sophisticated photographic equipment to observe what really happens inside the glass. The bubbles consist of carbon dioxide dissolved in the liquid during the méthode champenoise
fermentation process. Scientists have long known that these CO2 molecules need a niche of some sort to form bubbles; in a perfectly smooth glass, the molecules would evaporate singly and invisibly. Conventional wisdom is that tiny pits and gouges in the wall of a champagne flute serve as bubble-formation sites. But Liger-Belair found that the imperfections of an average wine glass are far too small for that purpose. Instead, what gives birth to the bubble is, ahem, dirt—dust particles on the glass, or cellulose strands from the dish towel used to dry it.
These specs of grime are perfect gathering places for the CO2 molecules. (Champagne, concedes Liger-Belair, is "a symbol full of contradictions.") He does, however, offer a science-based tip for tipplers: Don't eat peanuts or wear lipstick. The fat molecules in greasy snacks and lip glosses stretch and break the bubble walls, taking the fizz out of the entire experience. And while you may get no kick from knowing that champagne bubbles are caused by dirt in your flute, it's great trivia for pepping up dull party chitchat. Just don't tell your host.