A carbonating device for carbonating an opened vessel, the carbonating device comprising: an inlet for receiving pressurised gas, the inlet being opened and closed by an operable inlet valve; an exit for expelling gas from the carbonating device into a vessel to be carbonated, the exit being opened and closed by an exit valve; and a trigger mechanism for opening the operable inlet valve in order to allow gas egress through the inlet; wherein a trigger pressure regulator is arranged to automatically close the operable inlet valve when a predetermined first pressure value is exceeded within the carbonating device and a carbonating pressure regulator is arranged to automatically close the exit valve when a predetermined second pressure value is exceeded within the carbonating device, wherein the first pressure value is higher than the second pressure value; wherein the carbonating device comprises a discharge assembly and a cap assembly, the discharge assembly being able to be coupled and de-coupled from the cap assembly wherein the discharge assembly includes the inlet, inlet valve, trigger mechanism, and trigger pressure regulator and the cap assembly is suitable for sealing to a vessel to be carbonated and includes the exit; wherein the discharge assembly further includes a discharge port for discharging gas to the cap assembly, the discharge port being opened and closed by a discharge valve and a discharge pressure regulator is arranged to automatically close the discharge valve when a predetermined third pressure value is exceeded within the discharge assembly, the third pressure value being between the first pressure value and the second pressure value. an inlet for receiving pressurised gas, the inlet being opened and closed by an operable inlet valve; an exit for expelling gas from the carbonating device into a vessel to be carbonated, the exit being opened and closed by an exit valve; and a trigger mechanism for opening the operable inlet valve in order to allow gas egress through the inlet; wherein a trigger pressure regulator is arranged to automatically close the operable inlet valve when a predetermined first pressure value is exceeded within the carbonating device and a carbonating pressure regulator is arranged to automatically close the exit valve when a predetermined second pressure value is exceeded within the carbonating device, wherein the first pressure value is higher than the second pressure value; wherein the carbonating device comprises a discharge assembly and a cap assembly, the discharge assembly being able to be coupled and de-coupled from the cap assembly wherein the discharge assembly includes the inlet, inlet valve, trigger mechanism, and trigger pressure regulator and the cap assembly is suitable for sealing to a vessel to be carbonated and includes the exit; wherein the discharge assembly further includes a discharge port for discharging gas to the cap assembly, the discharge port being opened and closed by a discharge valve and a discharge pressure regulator is arranged to automatically close the discharge valve when a predetermined third pressure value is exceeded within the discharge assembly, the third pressure value being between the first pressure value and the second pressure value.