To solidify is to become solid, or to cause something to become solid: the transition from liquid to firm. In the kitchen it happens constantly: melted chocolate sets into a snap, gelatin turns stock into jelly, cooling fat firms on a roast’s surface, and ice cream hardens in the freezer. Each solidification follows its own chemistry, crystallisation of fats and sugars, gelation of proteins and starches, or simple freezing of water. Controlling it decides texture: tempered chocolate solidifies with a glossy snap, untempered with a dull bloom. Chefs manipulate solidification deliberately, chilling, freezing, and tempering to set exactly the texture they want. It is the quiet phase change behind countless dishes.