A hard candy (American English), or boiled sweet (British English), is a sugar candy prepared from one or more sugar-based syrups that is heated to a temperature of 160 °C (320 °F) to make candy. Among the many hard candy varieties are stick candy such as the candy cane, lollipops, rock, aniseed twists, and bêtises de Cambrai. “Boiled” is a misnomer, as sucrose (a disaccharide) melts fully at approximately 186 °C. Further heating breaks it into glucose and fructose molecules before it can vaporize.

Most hard candy is nearly 100% sugar by weight, with a tiny amount of other ingredients for color or flavor, and negligible water content in the final product. Recipes for hard candy may use syrups of sucrose, glucose, fructose or other sugars. Sugar-free versions have also been created.

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