Candy Thermometer Temperature Chart: Sugar Cooking Stages

How Sugar Stages Are Measured

Candy making relies on precise sugar concentrations, and temperature is the practical way to track them. As a sugar syrup boils, water evaporates and the boiling point rises. Each named stage—thread, soft ball, firm ball, and so on—corresponds to a narrow temperature range that predicts how the syrup will behave once cooled.

A candy thermometer measures the syrup directly, but altitude shifts the numbers. At sea level, water boils at 212°F (100°C); for every 1,000 feet above that, subtract about 2°F (1°C) from every target. A syrup that reads 238°F at sea level will reach the same stage at roughly 234°F in Denver.

The stages below assume sea level and a standard candy thermometer. Because thermometers vary, always test the syrup in cold water alongside the temperature reading, especially the first few times you work with a new recipe.

Thread Stage: 230–234°F (110–112°C)

The thread stage is the first recognizable step, reached shortly after the syrup begins to boil. Drop a little syrup from a spoon into a bowl of cold water; it forms a thin, liquid thread that does not ball up. This stage suits syrups, glazes, and some fruit preserves.

At this temperature the syrup still contains enough water that it flows freely. If you pull the cooled thread between your fingers, it feels like thin molasses. It will not hold any shape, which is exactly what you want for a pourable topping.

Recipes that call for thread stage rarely need a thermometer at all—a spoon test works fine—but a chart is useful when you are scaling a batch or working at altitude.

Soft Ball Through Hard Ball: 234–260°F (112–127°C)

The ball stages cover the most common candies. Soft ball, 234–240°F (112–116°C), produces fudge, pralines, and fondant. A syrup dropped into cold water forms a soft, pliable ball that flattens when pressed between your fingers. The texture depends on the exact temperature within the range: a few degrees makes fudge firmer or creamier.

Firm ball, 244–248°F (118–120°C), gives caramels and some nougat. The ball holds its shape but still yields to gentle pressure. Hard ball, 250–266°F (121–130°C), makes divinity, marshmallows, and some toffees; the ball is firm and holds its shape completely, though it still feels slightly tacky.

These stages are where small temperature differences matter most. A 2°F error at the soft ball stage can turn fudge grainy or too soft to cut. Let the thermometer settle for a few seconds before testing, and stir the syrup briefly to make sure the reading is even.

Soft Crack and Hard Crack: 270–300°F (132–149°C)

Soft crack, 270–290°F (132–143°C), is the stage for taffy and butterscotch. Syrup dropped into cold water separates into threads that are firm but still bend slightly before snapping. If the threads are brittle and snap cleanly, you have moved into hard crack.

Hard crack, 300–310°F (149–154°C), produces brittle, lollipops, and hard toffees. The cooled syrup is glassy and shatters when struck. At these high temperatures the syrup is extremely hot and can cause serious burns, so keep children away from the pot and use a long-handled spoon.

Beyond 310°F, sugar begins to caramelize and darken rapidly. The transition from hard crack to caramel happens in seconds, so stay at the stove and watch the thermometer continuously.

Caramel Stage: 320–350°F (160–177°C)

The caramel stage is different from the others because it involves chemical change, not just water loss. Once the syrup passes about 320°F (160°C), the sugar molecules begin to break down and re-form into compounds that taste nutty and toasty. The color shifts from pale gold to deep amber as the temperature climbs.

Caramel is used for sauces, pralines, and caramelized sugar decorations. There is no cold-water test for this stage—the syrup is too hot and the color is the better guide. Remove the pan from the heat just before it reaches your target shade, because residual heat continues to darken the syrup.

Because caramel burns easily and sticks to everything, many cooks use a wet pastry brush to wash down sugar crystals from the sides of the pan during cooking. That step is not about temperature, but it prevents the syrup from seizing or crystallizing before you reach your target.

Practical Tips for Accurate Readings

A thermometer only helps if it reads correctly. Clip it to the side of the pan so the bulb is fully submerged but not touching the metal bottom, which runs hotter than the syrup. Check the reading in boiling water before each use; if it is off by more than a degree, adjust your target temperatures or recalibrate.

Sugar syrups can foam and splash, so insert the thermometer before the syrup reaches a full boil. Stir gently while reading, and take the temperature at the center of the pot, not near the edges. For small batches, tilt the pan so the syrup pools deeply enough to cover the bulb.

Remember that the temperatures in a candy chart are targets, not guarantees. Humidity, pan width, and the type of sugar all influence how quickly the syrup cooks and how it behaves. Use the chart as a starting point, and trust the cold-water test when the two disagree.