Hard-Crack Stage in Candy Making

Boiled sugar is the base of all candy, from fudge to marshmallow. As its temperature rises, sugar goes through several stages, from thread to hard crack. Each stage corresponds to a texture or consistency—the hotter the syrup, the harder the candy. If you're making candy at home, you can determine the temperature of your syrup with a candy thermometer or a glass of cold water.

The Different Stages

Boiling syrup goes through six different stages: thread, soft ball, firm ball, hard ball, soft crack, and hard crack. Before you begin making candy, check your recipe: It will tell you when to take your boiling sugar off the heat. For instance, the thread stage is perfect for syrups and candied fruit, while fudge must reach the soft-ball stage in order to develop its characteristic soft chewiness.

When making candy, you should rely on both the cold water test and a candy thermometer for the most accurate results. Only seasoned candy makers memorize temperatures since most candy thermometers will display both temperature and stage.

Hard-Crack Stage

Hard-crack stage occurs at 300 to 310 F. If you don't have a candy thermometer, you can use the cold water test in a pinch: Drop a spoonful of hot syrup into cold water, then remove the candy from the water and attempt to bend it. If your syrup has reached the hard-crack stage, it will form brittle strands in the water and crack as you bend it.

Hard-Crack Stage Candies

Nut brittles, lollipops, and toffees must reach the hard-crack stage.