Device, comprising a platform for placing a vessel containing the liquid, a pipe with an open end configured for supplying steam to the vessel, a driving device configured to actuate a relative movement between the end of the pipe and the platform, means for determining a liquid level of the liquid in the vessel, and a control unit. The control unit is configured to actuate the driving device so that a relative initial position between the end of the pipe and the platform is assumed on the basis of the liquid level. The means for determining the liquid level comprise a weighing device. The control unit is then configured to determine the liquid level from the weight.
