There is provided a method of controlling aerosol production in an aerosol generating device the device comprising a powered aerosol generating element a flow channel configured to allow a flow of gas past the aerosol generating element and a flow sensor configured to detect the air flow in the flow channel comprising the steps of: determining a value of a first parameter related to a change in flow rate; and reducing a supply of power to the aerosol generating element depending on a result of a comparison between the value of the first parameter and a threshold value wherein the first parameter is derived from a combination of a second parameter that is a measure of a flow rate detected by the flow sensor and a third parameter related to the flow rate and wherein the third parameter is temperature power supplied to the aerosol generating element a maximum detected flow rate or a rate of change of flow rate or is derived from a combination of two or more of temperature power supplied to the aerosol generating element a maximum detected flow rate and a rate of change of flow rate. The invention provides a method of controlling aerosol production and in particular reducing or suspending aerosol production based not simply on a detected flow rate but on another measure indicative of the evolution of the flow characteristics.