Prep Tools

Candy Thermometer

Tracks the precise sugar stages for candy and frying

A high-range thermometer that tracks hot sugar through soft-ball, hard-crack, and caramel stages — and doubles for deep-frying. Those few degrees decide whether you get fudge or brittle. Clip it to the pot's side without touching the bottom.

A candy thermometer is a high-range thermometer that tracks hot sugar through its stages — soft-ball, hard-crack, caramel — and doubles for deep-frying. Those few degrees decide whether you get chewy fudge or shattering brittle, so precision matters more here than almost anywhere in cooking. Clip it to the pot's side, tip in the syrup but not touching the bottom.

Types & varieties

Clip-on dial / glass tube

Hangs on the pot rim with sugar stages printed on the scale; the traditional choice.

Digital probe (high-range)

Faster, easier to read, and often with an alarm at a set temperature.

Reading sugar stages

Sugar syrup passes through defined temperature stages, each giving a different candy texture — soft-ball (~115°C) for fudge, hard-crack (~150°C) for brittle, and on to caramel. The clip-on thermometer must be in the syrup but not touching the pan bottom, which is hotter than the liquid and gives a false high reading.

Soft-ball ~112–116°C: fudge, fondant
Firm/hard-ball ~120–130°C: caramels, marshmallow
Hard-crack ~149–154°C: brittle, lollipops, toffee
Keep the tip off the pan bottom for an accurate read

Common uses

Cooking sugar for caramel, toffee, and brittleMaking fudge and fondant to the soft-ball stageBoiling syrup for Italian meringue and marshmallowsMonitoring deep-frying oil temperatureReaching the exact stage for candy and confectionery

Tips & pitfalls

Clip it so the tip sits in the syrup but never touches the bottom of the pot.
Calibrate in boiling water first (100°C / 212°F at sea level) and note any offset.
Don't plunge a hot glass thermometer into cold water — let it cool or it can crack.
Brush down sugar crystals from the pan sides with a wet pastry brush to avoid graininess.
The same thermometer reads your frying oil — hold it at the right temp for crisp results.

Good to know

Range: Reads to ~200°C / 390°F (often higher), with sugar stages marked — caramel runs ~170–180°C
Types: Clip-on dial, glass-tube, or digital with a high-temp probe
Care: Let it cool before washing — thermal shock cracks glass
Price range: €10–35
Best for: Caramel, fudge, brittle, candy, deep-frying

Also called

sugar thermometer · frying thermometer