Substitute a bowl of cold water for a candy thermometer to tell the temperature of your candy. You can by checking the stage it is at by simply dropping some of the candy you are cooking into a bowl of cold water to see if it makes threads or balls up. There are several stages that candy goes through at different temperatures, so if you do not have a candy thermometer handy, use these tricks.
Drop a little of the candy into cold water to cool. If the candy forms a liquid thread that does not ball up, it is in the thread stage. This stage produces a type of sugar syrup but it is not yet candy. When your candy is in the thread stage, expect the temperature to be around 110 to 112C.
Drop some candy into cold water. If the candy forms a soft, flexible ball it is at a temperature of 113-115.5 degrees C or at the soft ball stage. Candies such as fudge and fondant are done when they are at the soft ball stage.
Drop a little bit of the candy into cold water. If it forms into a firm ball, it is in the firm ball stage. This stage is at a temperature of about 245 to 250 degrees Fahrenheit. Caramels and other similar candies are cooked to the firm-ball stage.
Take a spoon and dip it into your cooking candy. If the candy forms, thick threads when it drips from the spoon, it is at about 250 to 265 degrees Fahrenheit, or the hard ball stage. You can also drop some candy into cold water to see if it forms a hard ball that will not flatten, hence the term "hard ball stage." If you are cooking divinity or rock candy, it will be done at this temperature.
Watch the candy as it cooks. If it bubbles on top it is likely at the soft crack stage or at 270 to 290 degrees Fahrenheit. Alternatively, you can drop some of the candy into cold water. You will be able to tell if it is at this temperature when it solidifies into threads that are flexible but not brittle. Cook candies, such as butterscotch, to this temperature.
Drop your candy into cold water. If it forms hard, brittle like threads that easily break, you are at the hard crack stage, which his 300 to 310 degrees Fahrenheit. This is the highest temperature used to cook candy. Cook your toffee and lollipops to this temperature.
To avoid burns, allow the syrup to cool in the cold water before touching it.