Development and validation of a diode laser sensor for gas-phase CO2 monitoring above champagne and sparkling wines

Champagne and sparkling wines are multicomponent hydroalcoholic systems supersaturated with dissolved carbon dioxide (CO2). Under standard tasting conditions, CO2 progressively invades the headspace above glasses, thus progressively modifying the chemical headspace perceived by the consumer. Monitoring in situ, and as accurately as possible the level of gas-phase CO2 above liquid is therefore a challenge of importance aimed at better understanding the close relationship between the release of gas-phase CO2 and a collection of various parameters such as glass-shape, and champagne temperature, for example. The development and validation of an instrument which combines two infrared diode lasers coupled with an optical fiber and devoted to real-time monitoring of gas-phase CO2 above sparkling beverages are reported. A first set of data showing the impact of liquid phase temperature on the release of gas-phase CO2 found in the headspace of champagne glasses is presented.