Previous work on the stabilisation of air in cake batters led Brooker13 to propose a mechanism in which fat crystals effectively act as vehicles for the transfer of additional interfacial material to the surface of expanding bubbles during baking and thereby prevent their rupture. In this mechanism, fat crystals emerge from droplets of shortening in large numbers during the mixing process and become enveloped in a crystal–liquid interfacial layer which coalesces and becomes continuous with the gas–liquid interface of bubbles when they collide. As a result of this adsorption process, crystals are brought into direct contact with the gas in the bubble.