A method for treating a wort in a kettle provides a kettle with an inlet for feeding a wort into the kettle and with an outlet for flowing the wort out of the kettle. A heating means for bringing the wort contained in the kettle close to or at boiling temperature, as well as for controlling the temperature. A gas sparging system for sparging an inert gas into said wort. Feeding wort from a lautering step into said boiling kettle through the inlet, the wort at a temperature below its boiling temperature. During sparging, heating the wort and maintaining it at a treatment temperature below the boiling temperature of the wort for a duration between 15 and 90 min, and no longer than required to evaporate at most 4 wt. % of water initially in the wort. Transferring the treated wort to a trub separation step through the outlet.