The effervescence of bubbly beverages has captivated people for centuries, making it a tradition to uncork a bottle to mark special occasions, accomplishments, and good luck. We look at the difference between champagne bubbles and soft drink bubbles, and how researchers continue to dedicate their work towards the creation of a “better bubble.”
Are All Bubbles Created Equal?
While bubbles appear similar on the surface, effervescence is far from homogenous. In fact, bubbles vary significantly in their formation, characteristics, and ultimately, their value.
Perlage, a French term that translates to “the formation of pearls,” is the name for bubbles produced by the finest champagne and sparkling wines. They’re formed through a laborious process called méthode traditionelle, wherein a mixture of sugar and yeast is added to the wine, triggering a second round of fermentation within the bottle. This process produces more carbon dioxide (CO2) gas stored under pressure. When the bottle is opened, the decline in atmospheric pressure releases the CO2, creating the prized bubbles found in sparkling wines.
Perlage bubbles are distinguished from other types by their small size, fine texture, and long-lasting persistence. They rise slowly and steadily, forming a delicate column of bubbles that ascend to the surface. The smaller size of perlage bubbles contributes to their finer texture, and silky sensation upon consumption.
Soft Drink Bubbles
In contrast, soft drink bubbles cannot be considered perlage because of the effects of their production processes. Rapidly infusing CO2—as opposed to the fermentation process of méthode traditionelle—leads to the formation of larger bubbles that rise quickly and dissipate more rapidly. The coarser texture of soft drink bubbles is due to their larger size (and the possible presence of impurities in the liquid.) And unlike in sparkling wine, there is no column of bubbles to behold.
How Scientists Are Perfecting Perlage
Perlage is significantly valued in the sparkling wine industry and especially in Champagne, France. The prestige of champagne, after all, is largely built on the quality of its bubbles. Therefore, it’s no surprise that we need look no further than the University of Reims Champagne-Ardenne, to find perlage research at its finest.
The university’s “Effervescence & Champagne” research team is headed by Gérard Liger-Belair, the only researcher in the world to specialize in champagne bubbles. Their studies focus on the physicochemical processes linked to effervescence, such as the diffusion of CO2 in champagne by molecular dynamics. The wine industry is quick to take hold of their research as it assists them in producing more advanced effervescence techniques.
Researchers from Brown University and the University of Toulouse have also conducted groundbreaking studies related to the physics of bubbles in sparkling wine. Their findings shed light on why champagne bubbles rise in a straight line while those in other carbonated drinks tend to veer off to the side.
For instance, their research led them to define why surfactants, soap-like chemicals found in sparkling wine, stabilize bubble chains. Surfactants, which include proteins that contribute to the wine’s flavor, reduce the surface tension between the bubbles and the liquid, allowing them to rise in a more orderly fashion. Thanks to this research, winemakers have a leg up in controlling the effervescence and ensuring the consistency of their product.
The Best Shape to Keep Bubbles Bubbly
Along with wine producers, wine-glass makers benefit from these studies to create superior shapes that showcase bubbles at their finest. Scientists like Gérard Liger-Belair study why narrower bowls with a tapered shape (a flute glass) is our best route to bubble preservation after it has been served.
A narrow, tapered bowl restricts the release of carbon dioxide more than a wide bowl, allowing for a slower, more controlled ascent of bubbles and longer-lasting effervescence. Tapered bowls also channel bubbles to the center of the glass, encouraging the formation of the quintessential column. Even stem length plays a part as longer stems minimize heat transfer from the diner’s hand to the wine itself, preserving the cool temperature ideal for sparkling wine longer than a stemless glass.
The Bubble Economy
Bubbles are serious business. The pursuit of the perfect bubble in sparkling wine is a continuous endeavor that drives innovation and consumer excitement within the industry.
