How to use and maintain a food probe thermometer in your business: probe types, correct insertion, cleaning between foods, ±1°C accuracy and when to…
A probe thermometer is the single most important tool for proving your food is safe. To use one correctly, insert the clean, sanitised probe into the thickest part or centre of the food, wait for the reading to stabilise, and check it against known safe temperatures such as 5°C for cold storage, 60°C for hot holding and 75°C core for cooking. Keep it accurate to ±1°C, clean it between foods, and recalibrate regularly. Key takeaways: A working, accurate probe thermometer is expected under the Food Standards Code so you can verify potentially hazardous foods are held, cooked and cooled at safe temperatures.. Insert the probe into the thickest part or geometric centre of the food, avoid bone and the container base, and wait for the reading to stabilise before recording.. Clean and sanitise the probe before and after each use and between different foods to prevent cross-contamination.. Aim for accuracy within ±1°C; check against the ice-point (0°C) and boiling-point (about 100°C at sea level) and recalibrate or replace if it drifts.. Record checks so you can show due diligence to an authorised officer; confirm any state or council-specific requirements with your regulator.. Key temperatures to verify with your probe: Check point, Target, Note. Cold storage / display — 5°C or below — Potentially hazardous food kept cold. Hot holding / display — 60°C or above — Potentially hazardous food kept hot. Cooking core — 75°C in the centre — Common safe target for many foods. Ice-point calibration — 0°C (±1°C) — Ice slurry reference check. Boiling-point calibration — ~100°C at sea level — Slightly lower at altitude. Device accuracy — Within ±1°C — Required for measuring hazardous food. Why a probe thermometer matters Temperature is the main lever you control to keep potentially hazardous food safe. Bacteria multiply fastest in the temperature danger zone between 5°C and 60°C, so you need reliable proof that cold food stays at or below 5°C, hot food stays at or above 60°C, and cooking reaches a safe core temperature (commonly 75°C in the centre). A calibrated probe thermometer is how you gather that proof. The Australia New Zealand Food Standards Code requires food businesses to have a temperature-measuring device that is readily accessible and accurate to within ±1°C when measuring the temperature of potentially hazardous food. Fridge and oven dial gauges are not enough on their own — they measure air, not the centre of the food, and are often inaccurate. A hand-held probe lets you verify the actual food temperature at receiving, storage, cooking, hot holding, cooling and reheating. Types of probe thermometers Most Australian kitchens use a hand-held digital probe thermometer with a thin stainless-steel spike. It is fast, easy to read and simple to sanitise. Choose the style that matches how you work, and make sure whichever you pick can achieve ±1°C accuracy across the range you use. Digital penetration probe: the everyday workhorse for checking the core of solid and liquid foods; fast response and easy to calibrate.. Thermocouple or thermistor units: professional digital probes with quick, accurate readings; good for busy kitchens and detailed record-keeping.. Infrared (non-contact) thermometer: reads surface temperature only, useful for a quick screen of deliveries or display units, but it does not measure the core — always confirm with a penetration probe.. Bimetallic dial probe: cheaper analogue option, slower and harder to keep accurate; if used, calibrate it often.. Data-logging or wireless probes: handy for monitoring cook, cool and cold-storage over time, but still need periodic accuracy checks.. How to use a probe correctly Accurate readings depend on technique as much as the device. Insert the probe into the thickest part or geometric centre of the food, where it heats slowest and cools slowest. For thin items such as burger patties, insert sideways so the tip sits in the middle. Avoid touching bone, gristle, fat or the base and sides of the container, which read hotter or colder than the food itself. Wait for the number to settle before recording it — a few seconds for a fast digital probe, longer for a dial. For liquids like soups and sauces, stir first and take the reading in the centre. When checking a fridge or cold store, probe between packages or use a product left in for the purpose rather than relying on the air gauge alone. Cleaning and sanitising between foods A probe moves from food to food, so it can easily spread bacteria or allergens if it is not cleaned properly. Clean and sanitise the probe before you start, between different foods (especially between raw and ready-to-eat), and after you finish. Cleaning removes visible food and grease; sanitising then reduces bacteria to a safe level. Wipe alcohol-based probe wipes over the stem, or wash with warm soapy water, rinse, and apply a food-grade sanitiser used according to the manufacturer's contact time. Let it air-dry or use single-use paper. Never wipe a probe on a cloth, apron or tea towel between uses — that recontaminates it. Take extra care with allergen cross-contact: a probe used in a dish containing an allergen must be cleaned before it touches allergen-free food. Sanitise before the first use of the shift.. Clean and sanitise between raw and cooked, and between different products.. Use probe wipes or warm soapy water followed by a food-grade sanitiser.. Allow the correct sanitiser contact time before wiping or air-drying.. Store the clean probe in its sheath or a clean, dry spot — not loose in a pocket or drawer.. Accuracy and the ±1°C standard Under the Food Standards Code, your temperature device must be accurate to within ±1°C when measuring potentially hazardous food. Over time, probes drift through knocks, battery wear, moisture and heavy use, so you cannot assume a reading is right just because a number appears. The simplest way to check accuracy is against two known reference points: the ice point (0°C) and the boiling point (about 100°C at sea level, and slightly lower at altitude). If either check is more than 1°C out, the probe needs recalibrating (if it has that function) or replacing. Keep a small record of your checks — date, device, reference reading and result — so you can demonstrate due diligence. Some businesses also have probes professionally calibrated against a certified reference; confirm what your food safety program or regulator expects. When and how often to recalibrate There is no single legal interval that applies everywhere, so let risk and use guide you. A busy commercial kitchen commonly checks its main probes at least weekly, plus whenever a probe is dropped, exposed to extreme heat or cold, gives a doubtful reading, or has had its battery changed. Low-use devices can be checked less often, but always before a period of heavy reliance. The key is consistency and a written record. If a probe repeatedly fails the ice-point or boiling-point check, retire it — an inaccurate thermometer is worse than none because it gives false confidence. Build calibration checks into your daily or weekly cleaning routine so they actually happen. Confirm any specific frequency or method your state or territory regulator, local council or third-party food safety program requires. Check after any drop, knock or exposure to extreme temperature.. Check after changing the battery or if a reading looks wrong.. Do routine checks on a set schedule (many kitchens choose weekly).. Record every check and any corrective action taken.. Replace probes that fail repeatedly rather than nursing them along.. Checklist: Probe is clean and sanitised before first use.. Probe is cleaned and sanitised between different foods and between raw and ready-to-eat.. Readings taken in the thickest part or centre, away from bone and container walls.. Reading allowed to stabilise before recording.. Accuracy checked against ice-point and/or boiling-point on schedule.. Calibration checks and corrective actions recorded.. Faulty or out-of-tolerance probes replaced promptly.. Spare probe and batteries available as a backup.. Common mistakes: Relying on fridge or oven dial gauges instead of probing the food core.. Reading the surface with an infrared gun and assuming the centre is the same.. Wiping the probe on a cloth or apron instead of cleaning and sanitising it.. Touching bone, fat or the container base and recording a false reading.. Never calibrating, so a drifted probe gives false confidence.. Taking the reading before it has stabilised.. Keeping a probe that repeatedly fails the ice-point check..
How to calibrate a probe using the ice-point method
Fill a clean container with crushed ice, then top up with cold water to make a slushy mix. Stir and let it settle for a minute or two so it reaches a stable 0°C.
Put the sanitised probe into the centre of the slurry without touching the sides or base of the container, which are not at 0°C.
Give the reading time to stabilise. An accurate probe should read 0°C, within ±1°C (roughly -1°C to 1°C).
If your device has a calibration/reset function, adjust it to 0°C following the manufacturer's instructions. If it cannot be adjusted, record the offset and apply it to readings, or replace the probe if it is more than 1°C out.
For a second reference, place the probe in boiling water; at sea level it should read about 100°C (a little lower at altitude). Record the result and the date of the check.
Frequently asked questions
How accurate does my probe thermometer need to be?
It must be accurate to within ±1°C when measuring the temperature of potentially hazardous food, in line with the Food Standards Code. Check this against known reference points such as the ice point (0°C) and boiling point (about 100°C at sea level). If it drifts beyond ±1°C, recalibrate it or replace it.
How often should I calibrate my thermometer?
There is no single mandated interval that applies everywhere. Many busy kitchens check accuracy at least weekly, and always after a drop, extreme temperature exposure, battery change or a doubtful reading. Keep a written record of each check. Confirm any specific frequency your food safety program, regulator or local council expects.
What is the ice-point calibration method?
Fill a container with crushed ice and cold water to make a slurry at 0°C, stir, and insert the clean probe into the centre without touching the sides or base. An accurate device reads 0°C within ±1°C. If it can be adjusted, reset it to 0°C; if not, note the offset or replace the probe.
How do I clean a probe between different foods?
Clean off visible food and grease, then sanitise before the probe touches the next food, especially between raw and ready-to-eat items. Use probe wipes or warm soapy water followed by a food-grade sanitiser at the correct contact time, then air-dry. Never wipe it on a cloth, apron or tea towel, which recontaminates it.
Can I use an infrared thermometer instead?
An infrared thermometer only reads surface temperature, so it is useful for a quick screen of deliveries or display units but cannot tell you the core temperature. Always confirm cooking, cooling and reheating with a penetration probe inserted into the centre of the food, cleaned and sanitised between uses.
Where exactly should I insert the probe?
Insert it into the thickest part or geometric centre of the food, where it heats and cools slowest. Avoid bone, gristle, fat and the base and sides of the container. For thin items like patties, insert sideways so the tip sits in the middle, and stir liquids before probing the centre. Wait for the reading to stabilise.