Complete Sugar Stage Chart
| Stage | °F | °C | Cold Water Test | Used For |
|---|---|---|---|---|
| Thread | 230-234°F | 110-112°C | Forms a loose 2-inch thread | Syrups, glazes |
| Soft ball | 234-240°F | 112-116°C | Soft ball, flattens when removed | Fudge, fondant |
| Firm ball | 244-248°F | 118-120°C | Holds shape, flattens if pressed | Caramel candy |
| Hard ball | 250-266°F | 121-130°C | Firm ball, holds shape fully | Marshmallow, nougat, divinity |
| Soft crack | 270-290°F | 132-143°C | Threads bend before breaking | Taffy, butterscotch |
| Hard crack | 300-310°F | 149-154°C | Threads snap cleanly | Brittle, lollipops |
| Caramel | 320-350°F | 160-177°C | Turns golden to deep amber | Caramel sauce |
| Burnt | 350°F+ | 177°C+ | Dark, bitter, smells burnt | Not usable — discard |
Why Temperature Is Really About Water Content
Every candy recipe is fundamentally the same process: boiling a sugar-water mixture until enough water evaporates to reach a target sugar concentration. The temperature you're aiming for is really a proxy for that concentration — at the thread stage, the syrup is only around 80% sugar; by hard crack, it's nearly 99%. The higher the concentration, the harder and more brittle the candy sets once it cools, which is why the same basic ingredients (sugar and water) can become anything from a soft caramel to a glass-like brittle depending purely on how far you cook it.
The Cold Water Test
If you don't have a reliable thermometer, drop a small spoonful of the hot syrup into a bowl of very cold water and observe how it behaves once it cools in the water:
| Stage | What You'll See |
|---|---|
| Soft ball | Forms a ball that flattens on its own once removed from the water |
| Firm ball | Forms a ball that holds its shape but flattens when pressed |
| Hard ball | Forms a ball that holds its shape firmly, resists pressing |
| Soft crack | Separates into threads that are pliable and bend before breaking |
| Hard crack | Separates into threads that are brittle and snap cleanly |
The cold water test is a reliable backup, but the gap between stages narrows as temperatures climb — hard crack is only a 10-degree window — so a dedicated candy thermometer clipped to the side of the pot is worth using for anything past the soft ball stage.
Altitude Changes Your Target Temperature
Water boils at a lower temperature the higher your elevation, which means a sugar syrup reaches the same actual concentration at a lower thermometer reading than the numbers above assume (those are calibrated for sea level). Lower every target temperature in this chart by about 2°F for every 1,000 feet (305m) of elevation above sea level (our High Altitude Cooking Calculator works this out for your elevation). This is one of the most commonly overlooked adjustments in candy-making — a fudge recipe that consistently turns out grainy or won't set at higher elevations is very often an altitude problem, not a technique problem.
Regular Thermometer vs. Candy Thermometer
Most instant-read food thermometers are calibrated for meat and top out somewhere around 200-220°F — well short of the 300°F+ needed for hard crack candy. A dedicated candy thermometer, which clips to the side of the pot and reads well past 300°F, is the right tool for anything beyond the soft ball stage. Below that, an instant-read thermometer works fine.
Frequently Asked Questions
What temperature is the hard crack stage?
300-310°F (149-154°C). This is a narrow 10-degree window compared to other stages, and the sugar syrup is at nearly 99% concentration by this point — just a few degrees past 310°F and it starts to caramelize and burn rather than staying clear. A candy thermometer that reads accurately at this range matters more here than at any other stage.
Can I tell candy stages without a thermometer?
Yes, with the cold water test: drop a small amount of hot syrup into a bowl of very cold water and see how it behaves. A soft ball flattens when removed from the water; a hard ball holds its shape; a soft crack forms threads that bend before breaking; a hard crack forms threads that snap cleanly. It's a reliable backup, but a thermometer is more precise, especially for the narrow hard crack window.
Does altitude affect candy temperatures?
Yes. Water boils at a lower temperature at higher altitude, so a sugar syrup reaches the same actual concentration at a lower thermometer reading. Lower your target temperature by about 2°F for every 1,000 feet (305m) of elevation above sea level.
What's the difference between soft ball and firm ball stage?
Soft ball (234-240°F) forms a ball in cold water that flattens on its own when removed — used for fudge and fondant. Firm ball (244-248°F) holds its shape when removed but flattens if pressed — used for caramels. The 10-degree gap between them reflects a real difference in sugar concentration and final texture.