Crystals

Crystals are solids in which molecules or ions are arranged in a regular, repeating lattice, a structure that governs hardness, melting point, solubility and optical behaviour. In foods they appear as sugar grains, salt, ice, cocoa butter polymorphs and lactose in dairy products. Sugar refining shows the principle in action: raw sugar is mixed with a warm concentrated syrup and centrifuged in a magma to separate pure crystals from impurities. Controlling crystal size and form is a core quality task, since fine crystals give smoothness while uncontrolled growth causes grittiness, bloom or sandiness.