How to calibrate a food probe thermometer
Every temperature record in your diary is only as good as the probe behind it — and "how do you know your thermometer is accurate?" is a favourite EHO question. The check takes five minutes, costs nothing, and turns a stock answer into evidence.
The two-point check
- Ice-water check (0°C). Fill a container with ice, top up with a little cold water, stir, and wait a minute. Insert the probe without touching the sides. It should read between −1°C and +1°C.
- Boiling-water check (100°C). Insert the probe into freshly boiled water (carefully, and not touching the pan). It should read between 99°C and 101°C.
If either reading is outside roughly ±1°C, adjust the probe if it has a calibration screw or reset function, or replace it. A probe that reads 3°C high turns a genuinely safe 4°C fridge into a recorded 7°C — or worse, hides an 11°C fridge as a legal 8°C.
How often, and what to record
Weekly is a common and defensible routine for a busy kitchen; monthly is a reasonable minimum, plus any time the probe is dropped or gives readings that don't match the fridge display. Record the date, both readings, who did the check and what was done if it failed. Our free printable temperature log includes a calibration line for exactly this.
Probe hygiene while you're at it
Calibration proves accuracy; probe wipes prove the probe is not cross-contaminating between the raw chicken and the cooked rice. Keep wipes next to the probe and make wiping between uses part of the habit — officers watch for it during the inspection walkthrough.
Calibration records feed the same confidence-in-management score as your daily logs — see what EHOs check in temperature records.
Put this into practice with Localyn
Localyn gives cafes, restaurants and takeaways a digital SFBB diary, temperature and cleaning records, allergen management and inspection-ready reports — all in one place.