Unveiling self-organized two-dimensional (2D) convective cells in champagne glasses

Under standard tasting conditions, homogeneous stirring of champagne under the action of rising bubbles confers an advantage compared with a situation where the liquid phase would be at rest. Convection helps renewal of the immediate subsurface layers with champagne from the bulk, thus facilitating the evaporation of volatile organic compounds, and therefore better revealing the champagne bouquet. Here, spontaneous and self-organized two-dimensional convective cells were evidenced (at the air/champagne interface) in a laser-etched coupe poured with champagne, through laser tomography. Various regimes were evidenced, from a highly unstable 8-cells regime, to a very stable 4-cells regime. Moreover, by blowing air bubbles through a nozzle positioned at the bottom of a goblet poured with water, and by using Particle Image Velocimetry, similar 2D convective cells were also evidenced at the air/water interface, thus pointing out the crucial role of ascending bubbles behind the formation of self-organized 2D convection cells. (C) 2016 Elsevier Ltd. All rights reserved.