An accurate thermometer is your most important food safety tool — but only if it’s calibrated. Here are the two methods the food handler exam tests.
Ice-point method (most common)
- Fill a glass with crushed ice, then add cold water and stir.
- Insert the thermometer stem into the center without touching the glass.
- Wait until the reading stabilizes — it should read 32°F (0°C).
- If not, adjust the thermometer to 32°F.
Boiling-point method
- Bring water to a rolling boil and insert the stem.
- It should read 212°F (100°C) at sea level (lower at high altitude).
- Adjust if needed.
When to calibrate
- Before each shift or delivery
- After dropping the thermometer
- After a big temperature change (e.g., from cold to hot food)
- At regular intervals during the day
On your exam: the ice-point reading is 32°F and the boiling point is 212°F at sea level.
Frequently asked questions
What temperature should a calibrated thermometer read in ice water?
32°F (0°C) using the ice-point method.
How often should you calibrate a food thermometer?
Before each shift, after it’s dropped, after large temperature changes, and regularly during the day.
Ready to test yourself? Take our free food handler practice test (instant answers and explanations), or review the full food handler study guide.