Provided herein is a method of generating aerosol from an aerosol-generating substrate using an aerosol-generating device with at least one heat source disposed to heat, but not burn, the aerosol-generating substrate in use. The aerosol-generating substrate has first and second portions having substantially the same composition, and/or has first and second portions and there is no physical separation between the portions. The method includes heating the aerosol-generating substrate in the aerosol-generating device, so that a temperature profile of the first portion of the aerosol-generating substrate during heating is different from a temperature profile of the second portion of the aerosol-generating substrate.