Corn syrup is a thick, clear-to-pale-amber glucose syrup made by breaking cornstarch down into sugars — mostly glucose, maltose and longer glucose chains, with essentially no fructose in ordinary "light" corn syrup. Mild, only moderately sweet and prized above all for the way it refuses to crystallise, it is the backbone of American candy-making, frostings and pecan pie, and the everyday anti-crystallisation staple that keeps sauces, caramels and ice creams smooth.