Kitchen thermometer basics

A thermometer checks the middle

The outside of food heats first. A browned chicken breast can still be undercooked in its centre, while safely cooked meat can sometimes retain pink colour. A digital probe measures temperature at its tip or sensing area. It does not measure the whole meal at once, so where you place it matters. Read the instructions to find the sensing area and response time.

Have these ready

• A working digital food probe with its instructions, a timer showing seconds, a clean plate or tray, and the maker-approved cleaning and food-contact disinfecting supplies. A forehead, room or infrared surface thermometer is not a substitute for a probe in the centre of food.
• The cooking method and its required temperature-and-time combination. For food that needs thorough cooking, UK guidance includes 75 degrees C for 30 seconds or 70 degrees C for 2 minutes.
• Clean utensils for cooked food, separate from those used to handle raw meat.
• A safe place to set the hot pan while checking. Avoid reaching through rising steam.

Practise a reading without hot food

1. With the cooker off, clean and disinfect the probe using the care lesson. Put about 200 ml room-temperature drinking water in a stable cup or bowl holding at least 400 ml, on a clear worktop. The water must be deep enough to cover your probe's stated sensing area without reaching its handle or electronics; use a suitable deeper vessel if needed.
2. Switch on using the button or unfolding action in the manual, and select degrees C. Hold the handle, not the sharp metal tip. Lower the sensing area into the water without touching the cup's sides or bottom. Keep the display and handle dry.
3. Wait for the reading to settle for the response time in the instructions. Move the tip slightly through the water, then hold it still again. Practise reading the number without lifting the tip out of the water. There is no target cooking temperature in this cold exercise, and room temperature is not an accuracy calibration.
4. Lift the probe out carefully. Put it on the clean tray, empty the practice water and clean/disinfect and dry the probe again before storage. Protect the point in its clean sheath or folded position as its maker directs.

Take a useful reading

• Thermometer cleaning and careClean the probe before use and between raw or undercooked and cooked checks.

1. Clean and disinfect the probe before use. Check degrees C and have the seconds timer ready. Put the hot pan on a stable trivet, away from the edge, and use a separate clean utensil to steady a piece if needed; do not hold hot food in your fingers. Keep the probe handle out of steam and away from the hot pan.
2. Push the tip steadily into the thickest part so the complete sensing area reaches the centre. For a thin chicken breast, approach from the side. Do not stab, lever, lift or turn food with the probe. If the piece is too thin to cover the sensing area, use a suitable thin-tip food probe rather than accepting a shallow surface reading.
3. Avoid touching bone, the pan or a large pocket of fat. These can give a reading that does not represent the centre of the meat.
4. Wait for the display to settle as the device instructions require. Check several thick areas and each piece when pieces differ in size or may have heated unevenly. For soup or sauce, stir with a clean spoon, then check the liquid with the sensing area covered, away from the pan bottom and sides; do not assume bubbles at an edge prove the centre is hot.
5. Use the lowest relevant reading. If the food has not reached the required combination, continue cooking and check again with a cleaned probe.
6. For 75 degrees C for 30 seconds, the coldest checked area must stay at or above 75 for the full 30 seconds; briefly flashing 75 is not the same test. Use the timer while the probe stays correctly positioned if its instructions permit. A 70 degrees C check needs the full 2 minutes instead. If the reading drops below the chosen threshold, continue cooking and restart that check with a cleaned and disinfected probe. Recheck other potentially cooler areas rather than averaging them. Never close a hand-held probe in a hot oven or put it in a running microwave; if you cannot safely hold the reading, use suitable rated equipment or a different validated checking method.

What needs thorough cooking

Poultry, pork, minced meat, sausages, burgers and rolled or stuffed joints need thorough cooking. An intact beef or lamb steak has different guidance, but that exception does not extend to a burger or meat pierced, rolled or mechanically tenderised. Use the meat temperature reference and product instructions when uncertain.

When the reading seems wrong

Check the units, battery and insertion position. Move the probe to another central spot rather than accepting a convenient higher number. A very fast jump may mean the tip touched the pan. A thick joint needs checks in several places. Do not average a low reading with a high one.

Look after the instrument

An instant-read probe is not automatically suitable to leave in the oven. Keep its display out of water unless the manufacturer explicitly permits immersion. Store it clean and dry, protected from bending. A probe is a useful safety tool, but it cannot make food safe after poor storage or tell you whether a use-by date can be ignored.