When it comes to champagne tasting, dissolved CO2 is a key compound responsible for the very much sought-after effervescence in glasses. Nevertheless, the slow decrease of dissolved CO2 during prolonged aging of the most prestigious cuvees raises the issue of how long champagne can age before it becomes unable to form CO2 bubbles during tasting. Measurements of dissolved CO2 concentrations were done on a collection of 13 successive champagne vintages stored in standard 75 cL bottles and 150 cL magnums showing prolonged aging ranging from 25 to 47 years. The vintages elaborated in magnums were found to retain their dissolved CO2 much more efficiently during prolonged aging than the same vintages elaborated in standard bottles. A multivariable exponential decay-type model was proposed for the theoretical time-dependent concentration of dissolved CO2 and the subsequent CO2 pressure in the sealed bottles during champagne aging. The CO2 mass transfer coefficient through the crown caps used to seal champagne bottles…