skirt 138 is formed with downwardly projecting elements 139 leaving between them raised arches or crenellations 140 such that when the mixer is resting on or is pushed vertically down onto the bottom of a container fluids may pass under arches 140 as well as through openings 137 between struts 136 preferably downwardly projecting elements 139 are formed with relatively sharp edges 142 which can assist in breaking up lumps of material such as for example pieces of banana or other fruit to assist in the mixing action of the blade assembly cage 134 and blade assembly 152 are configured so as to leave reasonable clearance between the periphery of the rotating discs of the assembly and the struts of the cage this together with the general bell shape of the cage allows a user to bring the mixing action close to the sides of a container but precludes contact between the blade assembly and the container blade assembly 152 is preferably formed of a relatively flexible plastic and with rounded edges so that the risk of laceration of fingers inadvertently inserted is at least reduced in those preferred embodiments of the blade assembly discussed in more detail below which have a lower angled disc element that element rotates in close proximity to.