Cooking Temperatures and Probe Thermometers: Getting Hot Food Actually Safe

Every temperature guide so far has been about keeping food cold. This one is about the other half: cooking food hot enough to make it safe, proving it with a thermometer, and keeping it hot until it's served. Guessing is not a method — colour, texture and time are all unreliable indicators, and a probe thermometer is the only tool that actually answers the question "is this cooked?"

Core temperature: what "cooked" actually means

Pathogens in the centre of a piece of meat are killed by temperature held for time. The safe target is a core temperature — measured at the thickest part, away from bone, fat and the pan — high enough that the centre of the food is pasteurised.

The widely used food-safety benchmarks:

• Whole cuts of beef and lamb (steaks, roasts) — pathogens sit on the surface, so searing the outside matters most; the centre can be cooked to preference.
• Minced, rolled, tenderised or mechanically processed meat — surface bacteria have been mixed through, so the WHOLE piece must reach core temperature. This includes burgers, sausages, mince dishes and anything pinned or injected.
• Poultry and pork — must reach core temperature throughout; no pink, no runny juices, and probe-verified.

The exact figures come from your food-safety authority and your HACCP plan — write the targets into your cooking procedures so every cook uses the same numbers, and record them. (The temperature danger zone logic is in the fridge guide; this is its mirror image.)

How to probe correctly (the part people get wrong)

A thermometer only tells the truth if you use it properly:

• The thickest part, away from bone (bone conducts heat differently and gives false readings), away from fat pockets, and not touching the pan.
• Wait for the reading to settle — instant-read still takes several seconds to stabilise.
• Check multiple pieces and multiple spots in a batch. One probe reading proves one reading, not the tray.
• Clean and sanitise the probe between uses — a probe that goes from raw chicken to cooked chicken without cleaning is a cross-contamination tool. Alcohol wipes or hot soapy water between tests.
• Record it. The probe reading in the log is your proof the batch was safe. "I checked it" isn't evidence; the log is.

Calibration: the check nobody does

A thermometer that's wrong is worse than no thermometer — it gives false confidence. Calibrate probes regularly (weekly is common practice, plus after any knock or drop):

• Ice-point method: stir the probe in a glass of crushed ice and water, wait for the reading to settle; it should read 0°C. Adjust or note the offset.
• Boiling-point method: in actively boiling water it should read close to 100°C (slightly less at altitude — Johannesburg water boils around 95-96°C, which is physics, not a broken probe).

Log the calibration too. And replace probes that drift badly — they're cheap; food poisoning isn't.

Reheating: the second cook is the risky one

Reheated food has already been through the danger zone once. The rules:

• Reheat thoroughly, to core temperature — not "until it looks hot".
• Reheat once. Every cool/reheat cycle is another pass through the danger zone and another hit to quality.
• Reheat fast. A bain marie is a holding device, not a reheating device — it will hold food hot but it heats too slowly to be safe for reheating from cold. Reheat in an oven, microwave or on the range, then transfer to holding.
• If reheated food won't be served immediately, it goes straight into hot holding — not onto a bench.

Hot holding: keep it hot or cool it fast

Cooked food waiting to be served sits in the danger zone unless you act:

• Hold it hot (in a bain marie, hot cupboard or under heat lamps) at or above the hot-holding temperature in your HACCP plan, and check it with the probe on a schedule — displays drift and dishes dry out at the edges.
• Or cool it fast (see the fridge guide's cooling rules) for later service.
• The middle option — sitting on a bench at room temperature "for a bit" — is the one that causes outbreaks.

Frequently asked questions

Do I really need to probe everything?

Probe every batch of high-risk food: all poultry, all pork, all minced and processed meat, and anything reheated. Whole intact cuts of beef and lamb are the exception — surface searing handles those — but the moment meat is minced, rolled or tenderised, the surface bacteria are inside and the whole piece needs a verified core temperature.

Why does my probe read different temperatures in the same pot?

Either the pot genuinely has hot and cold spots (stir it and re-test), or the probe needs calibrating. Run the ice-point test: in stirred ice water it should settle at 0°C. A probe that reads several degrees off is telling you lies at cooking temperature too.

Can I judge doneness by colour or juices?

No — colour is unreliable (some meats stay pink when safe, some brown before they're safe), and clear juices don't guarantee core temperature. These are folk methods; the probe is the method. Colour can tell you the probe is worth using, never that you can skip it.

Is a bain marie a safe way to reheat food?

No. A bain marie holds food hot; it heats too slowly to be a safe reheating method — food lingers in the danger zone on the way up. Reheat in an oven, microwave or on the range to core temperature first, then transfer to the bain marie for holding, and log both steps.