When using a soda siphon to make carbonated water, one suggestion (in the instructions of the siphon) to increase the fizziness is that you use very cold water. This does not make sense to me since solubility generally increases with decreased temperature. Shouldn’t hotter water be fizzier since more CO2 can dissolve?
ANSWER PERSON RESPONDS: You want as much carbon dioxide to be dissolved in the water as possible, so you’d want it cold to get it as loaded with CO2 as possible. As the liquid warms up, there’d be that much more gas to percolate out into the atmosphere. If it started out hot, it wouldn’t have had the CO2 dissolved in it in the first place.