Solubility of CO2 in water at 0C and roughly atmospheric pressure is about 0.001337 mole fraction [0]. CO2 molecules are 44/18 times heavier than water molecule

Solubility of CO2 in water at 0C and roughly atmospheric pressure is about 0.001337 mole fraction [0]. CO2 molecules are 44/18 times heavier than water molecules, so that's about 3.3g of CO2 dissolved in a liter of water. Carbonated water is usually specified in "volumes of CO2". One mole of gas at STP has a volume of about 22.4L, so one liter of CO2 weighs about 2g. "Lightly carbonated" is usually considered about two volumes of dissolved CO2, so 4g/L, which isn't much higher than 3.3g. Assuming the packaging is sealed well enough to maintain a high percentage of CO2 within, and the temperature is low enough, it looks plausible that there would be a noticeable change in taste/mouth-feel. This is confirmed by a study I found showing average taste threshold for dissolved CO2 in water of 0.26g/L [1]. [0] http://sites.chem.colostate.edu/diverdi/all_courses/CRC%20reference%20data/solubility%20of%20carbon%20dioxide%20in%20water.pdf http://sites.chem.colostate.edu/diverdi/all_courses/CRC%20re... [1] https://home.zhaw.ch/yere/pdf/Teil16%20-%20Expression%20of%20Multidisciplinary.pdf https://home.zhaw.ch/yere/pdf/Teil16%20-%20Expression%20of%2... The theory supports ars. Calculate before you downvote.