Fresh product Crust: low water content, solid, very brittle = glassy state Crumb: high water content, starch is gelatinised due to baking = rubbery state Staled product Crust: upon storage, water migrates from the crumb to the crust, and this softens the crust. The crust changes to the rubbery state. Crumb: the state in the crumb can crystalline (starch retrogradation that follow gelatinisation). Water is lost to the crust and the environment, and also the crystals will incorporate water. As a result, the crumb becomes firmer and crumblier.