How Does Gas-Phase CO₂ Evolve in the Headspace of Champagne Glasses?

The chemical space perceived by a consumer of champagne or other sparkling wines is progressively modified all along tasting. Real-time monitoring of gas-phase CO₂ concentration was performed, through a CO₂-diode laser sensor, along a two-dimensional array of nine points in the headspace of three types of glasses poured with champagne. Two original glasses with distinct headspace volumes were compared with the standard INAO tasting glass. For each of the three glass types, a kind of temperature-dependent CO₂ fingerprint was revealed and discussed as a function of the glass geometry and headspace volume. Moreover, a simple model was developed, which considers the rate of decrease of the concentration of gas-phase CO₂ in the headspace of a glass after the pouring process as being mainly ruled by natural air convection in ambient air. The timescale which controls the rate of decrease of gas-phase CO₂ was found to highly depend on the ratio of the headspace volume to the open aperture of the glass.