In a method of carbonating a beverage using a carbon dioxide diffusingstone, temperature is measured in a flow of that beverage immediatelybefore the flow changes from laminar to effervescent, thereby obtaininga true temperature at which carbon dioxide is diffused into the beverage.In another aspect of the present invention, there is provided a portablecontroller having connectors joinable to a gas pressure regulator of a gascylinder and to any one of several beverage carbonation containers. Theportable controller has instruments therein for controlling a flow ofcarbon dioxide gas to the beverage in any one of the containers and forcontrolling a pressure gradient of the carbon dioxide gas in the beverageover a period of time. There is also provided an elongated carbondioxide diffusing stone assembly having an elongated temperature probewell extending parallel to and immediately below a diffusing stone.
