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. 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.