Crystallization and Inversion

Graininess is a common fault in many candies and desserts. Graininess results when cooked sugar crystallizes—that is, turns to tiny sugar crystals rather than staying dissolved in the syrup. If even one sugar crystal comes in contact with a cooked syrup, it can start a chain reaction that turns the whole thing into a mass of sugar crystals. This effect of sugar crystals on a syrup is called seeding.