United States
Hong KongMicrowaves: 165°F, covered, rotated, and two minutes standing
Food cooked in a microwave must reach 74°C (165°F), be covered during cooking, be rotated or stirred partway through, and stand for 2 minutes afterwards before serving or temperature measurement.
One number for everything, which makes microwaves simpler than any other cooking method and slightly odd for the same reason.
The four requirements
- Cook to 74°C (165°F), whatever the food.
- Cover the food during cooking.
- Rotate or stir it partway through.
- Let it stand for 2 minutes after cooking.
All four are Code requirements, not techniques. Questions typically give you three and ask for the fourth, or describe a process missing one.
Why 165°F for everything
Microwaves heat unevenly. Energy is absorbed differently by fat, water and sugar, so one part of a dish can be well past boiling while another is still at 45°C (110°F). Same dish, same moment.
The Code responds by requiring a single higher temperature rather than trying to specify a per-food number that a microwave cannot reliably deliver anyway.
The standing time
Two minutes, and it is doing real work rather than being a courtesy.
Heat continues to move from hot spots to cold spots after the microwave stops. The standing time is when the cold spots come up, which means it is part of the cooking process rather than something that happens afterwards.
A reading taken straight out of the microwave measures a hot spot or a cold spot depending on where the probe lands. The temperature check belongs after the standing time, and a question describing an immediate reading is testing that.
Covering and rotating
Covering retains moisture, which promotes even heating and prevents splatter contaminating the oven interior. Rotating or stirring redistributes food through the uneven energy field.
A turntable satisfies the rotation requirement. Stirring satisfies it for liquids, and does it better.
Thawing
Microwave thawing is permitted only where the food goes immediately into cooking, because thawing leaves warm patches already in the danger zone.
Thawing in a microwave and returning the food to the cooler is a violation, and it is the version that appears in thawing questions.
The exception worth knowing
Commercially processed, ready-to-eat food that is heated for immediate hot holding only needs 57°C (135°F) - including in a microwave.
That is a narrow case and a genuine one, and it is offered as an answer option often enough to be worth recognizing.
Common questions
What temperature must microwaved food reach?
74°C (165°F), whatever the food. A single higher temperature is required because microwaves heat unevenly and cannot reliably deliver a per-food number.
Why does microwaved food need standing time?
Heat continues moving from hot spots to cold spots after the microwave stops. The two minutes are when the cold spots come up, which makes standing part of the cooking process.
When do you take the temperature?
After the standing time. A reading taken immediately measures whichever spot the probe happened to land in, which tells you very little.
Does food have to be covered in the microwave?
Yes. Covering retains moisture, which promotes even heating, and it prevents splatter contaminating the oven interior. Rotating or stirring is also required.
Can you thaw food in a microwave?
Only if it goes straight into cooking afterwards. Microwave thawing leaves warm patches already in the danger zone, so returning the food to a cooler is a violation.