How to Test Candy Temperatures Without a Thermometer

Use cold water to figure out the temperature of your candy

find candy temperature without a thermometer illustration

Illustration: © The Spruce, 2018

Don't let your lack of a candy thermometer stop you from making candy! You can test your candy temperature without a thermometer.  

You can figure out your candy's temperature by using this simple trick, known as the cold-water method. This easy procedure has been used by cooks for generations and is useful for cooking all types of candies, from fudges to caramels to toffees.

For any recipe that calls for a candy thermometer, all you'll need is a bowl of cold water instead (the colder the better—ice water is fine!).

While the candy is cooking, periodically drop a small spoonful of the candy into the bowl of cold water. Immerse your hand in the water, try to form the sugar into a ball, and bring it out of the water. The shape and texture of the resulting sugar blob will tell you the approximate temperature of your candy. Use the chart below to translate the sugar's shape into a numerical temperature.

Example: You want to make a fudge recipe that calls for the sugar to be cooked to 236 F, or "soft ball" stage. After the sugar syrup comes to a boil, you start dropping a small spoonful of candy into the cold water in intervals a few minutes apart. At first, the sugar syrup is stringy and shapeless, but after several tests, it starts to hold its shape. When it reaches the stage that it can be formed into a soft ball, then you know that your fudge is ready and you can take it off the heat! This method isn't as precise as using a thermometer, and it requires a bit of practice, but it's a great technique to have in your arsenal if ever you find yourself without a thermometer.

If you'd like to see pictures of what each stage of candy cooking looks like, check out the illustrated guide to candy temperature testing.

Candy Temperature Chart

Thread223-235 FThe syrup drips from a spoon and forms thin threads in waterGlacé and candied fruits
Soft ball235-245 FThe syrup easily forms a ball while in the cold water but flattens once removedFudge and fondant
Firm ball245-250 FThe syrup is formed into a stable ball but loses its round shape once pressedCaramel candies
Hard ball250-266 FThe syrup holds its ball shape when pressed, but remains stickyDivinity and marshmallows
Soft crack270-290 FThe syrup will form firm but pliable threadsNougat and taffy.
Hard crack300-310 FThe syrup forms brittle threads and easily cracks and snapsBrittles and lollipops
Caramel320-350 FThe sugar syrup will turn golden brown and have a fragrant caramel smellCaramel syrup, Pralines

A word of caution: Please be careful when working with hot sugar, especially if you decide to use the cold-water method. Sugar burns are nasty. Hot sugar is almost impossible to quick rub or rinse off the skin, and it will continue burning long after it comes into contact with your skin. Please don't allow yourself to be sloppy or distracted when working with hot sugar, and avoid dangling hair, jewelry, or clothing.