Candy temperature calculator

What are the candy temperature stages?

The University of Illinois Extension lists six stages, tested by dropping a little hot syrup into cold water: thread 230 to 234 °F (110 to 112 °C), soft ball 234 to 240 °F (112 to 116 °C), firm ball 244 to 248 °F (118 to 120 °C), hard ball 250 to 266 °F (121 to 130 °C), soft crack 270 to 290 °F (132 to 143 °C) and hard crack 300 to 310 °F (149 to 154 °C). The higher the temperature, the less water is left and the harder the candy.

What temperature is soft ball stage?

234 to 240 °F (112 to 116 °C) at sea level. A little syrup dropped in cold water forms a ball that flattens and loses its shape when you take it out. Illinois Extension lists fudge, fondant and pralines at this stage, and Colorado State Extension gives the same 234 to 240 °F for creamy candies and fillings.

How do I adjust candy temperature for altitude?

Colorado State Extension’s rule of thumb is to subtract 2 °F from the recipe for every 1,000 feet above sea level, because water’s boiling point drops about 1 °F for every 500 feet. At 5,000 feet water boils at about 202 °F, 10 °F lower than at sea level, so a 238 °F fudge recipe should be cooked to 228 °F. Its example at 10,000 feet: a 236 °F recipe becomes 216 °F. The faster evaporation at altitude makes sugar mixtures too hard or grainy if the recipe is not adjusted.

How do I calibrate a candy thermometer?

Boil plain water and read the thermometer. Target = stage temperature − (212 °F − your boiling reading). At sea level a thermometer that reads 210 °F in boiling water is 2 °F low, so a recipe that says 240 °F is cooked to 238 °F; one that reads 214 °F is 2 °F high, so cook to 242 °F (Illinois Extension). At altitude the same subtraction folds in the elevation: Utah State Extension’s example is water boiling at 204 °F, so a 230 °F recipe is cooked to 222 °F. Check on the day you cook, because weather changes the boiling point slightly.

Why do different sources give different candy temperatures?

The stages describe how the syrup behaves in cold water, not exact thresholds, and each university draws the lines a little differently: firm ball starts at 242 °F in New Mexico State’s table but 244 °F in the others, and hard ball ends at 260, 266 or 268 °F. This calculator follows the University of Illinois Extension table. When a recipe gives its own temperature, use that and let the cold-water test confirm it.

Does the cold-water test change at high altitude?

No. New Mexico State Extension says the cold-water test stays reliable at any elevation because it depends only on how the candy looks in cold water. If your thermometer and the test disagree, trust the test.

The stages in three university tables

The cold-water test by stage, from the Illinois table: thread forms 2-inch threads; soft ball forms a ball that flattens when removed; firm ball forms a ball that holds its shape; hard ball is hard and firm; soft crack gives hard, pliable threads that crack when touched; hard crack gives fine, hard, brittle threads that separate. Fudge, fondant and pralines sit at soft ball, caramels at firm ball, divinity at hard ball, taffy at soft crack, and brittles and toffee at hard crack.

Baking at altitude too? See the high altitude baking calculator, convert recipes with the oven temperature converter and the cooking measurement converter.

Take care with hot syrup and keep children away from the stove. Colorado State Extension also warns that an older mercury candy thermometer, if broken, must be handled and disposed of as hazardous waste. Sources: University of Illinois Extension, 4-H Cooking 401 (ME0123, 2010), “Temperatures for Candy Making”; Colorado State University Extension, “Candy Making at High Elevation” (reviewed October 2025); New Mexico State University, Guide E-215 “High-Altitude Cooking” (revised November 2015); Utah State University Extension, “The Art of Candy Making” (November 2009); Colorado State University Extension, “High Altitude Food Preparation” (boiling-point table). How we check our calculators.