Can You Reheat Food Twice? Why Food Safety Advice Says Once
Reheat food once, because the warm wait between two reheats adds risk, and reheating does not remove toxins formed earlier. The Centre for Food Safety in Hong Kong advises against reheating more than once.
At a glance
- Reheat count: once. The Centre for Food Safety says not to reheat more than once.
- Target: at least 75 °C at the centre of the food.
- Second reheat: not recommended, because each warm stage adds time at temperatures where germs can grow.
- Refreezing: generally not recommended once food has thawed.
- The line to remember: heat only the portion you will eat, and the second reheat never happens.
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This is the question that starts the argument about salan heated at lunch and again at dinner. The short version is that the number of reheats matters as much as the temperature, and the safe number is one.
Why is a second reheat riskier than the first?
Each time food goes back into the warm range, it spends more time in the stage where bacteria can grow and toxins can form. The Centre for Food Safety says that food which has been cooled and then served hot should be reheated thoroughly and not reheated more than once. Reheating can kill the bacteria, but the heat-stable toxins they already made remain, so a second reheat does not reset anything. It only adds another warm stage on top of the first.
Texture and flavour usually suffer with each round too. That is a cooking observation, not a safety rule, but it is one more reason to stop at one.
| Reheat step | Advice | Why |
|---|---|---|
| First reheat | Heat to at least 75 °C at the centre | Brings the food up to the target |
| Second reheat | Not recommended | Adds another warm stage |
| Refreezing after reheat | Generally not recommended | The Centre for Food Safety advises against refreezing thawed food |
Can you reheat rice, chicken or soup twice?
No. The Centre for Food Safety wording covers chilled food served hot in general, so rice, chicken and soup all follow the once rule. Rice is often the example people ask about. Food held warm for hours can build up heat-stable toxins that reheating does not remove. For chicken and soup, heat them to 75 °C at the centre, eat what you need, and do not put the rest back through another warm cycle.
How hot does reheated food need to be?
The target is at least 75 °C at the centre of the food, which the Centre for Food Safety gives for chilled food served hot. A thermometer gives an exact check. At home, bubbling is only a visual cue, so use a thermometer where you can. Stir, heat until it bubbles all through, and check the middle of the dish rather than the edges.
Can you refreeze leftovers after reheating?
Generally no. The Centre for Food Safety says refreezing thawed food is generally not recommended, with one exception: where the thawed food has stayed below 4 °C. So the simplest rule is to thaw and reheat only what you will eat in one sitting. Food thawed in a microwave or under cold running water has to be cooked straight away. The wider freezing side of this is in the guide to freezing cooked food.
How do you reheat only what you will eat?
Portion the food on the day you cook it, so the second reheat never has to happen. Keep the rest cold and reheat one portion at a time. For anyone who cooks a big pot on Sunday and eats from it all week, this habit removes the second reheat altogether.
Try this: take out katori sized portions
Keep the big pot in the fridge, and take out one katori sized portion each time. The pot itself is never reheated, and each portion gets exactly one reheat. For salan, the guide to storing salan so it tastes better the next day explains how to store salan safely.
- Take one portion from the cold pot and put it in a pan or microwave dish.
- Add a splash of water for curries or dal, and cover the pan so the steam stays in.
- Heat on medium, stirring, until the food bubbles all through and the centre is at least 75 °C.
- Serve it straight away, and do not return any leftover reheated food to the fridge or the freezer.
Stir partway through, let the dish stand for a moment, and then check the centre. The microwave safety guide for a desi kitchen covers the wider picture. For foods that need extra care when reheated, see the guide to which foods should not be reheated.
Take extra care with food for babies, older adults and anyone with a weakened immune system. Serve those people food that has been reheated once, is steaming hot all the way through, and is not a second round. If vomiting or diarrhoea follows, call 111 when vomiting has lasted more than two days or diarrhoea more than seven days, and call 999 for blood in vomit, confusion or severe breathing difficulty. Speak to a pharmacist if signs of dehydration appear, such as dark, smelly pee or peeing less than usual.
Reheating food twice: your questions answered
How many times can you reheat food safely?
Once, because the Centre for Food Safety advises not reheating food more than once.
Is it bad to reheat food twice?
Yes, it adds a second warm stage, and reheating does not remove toxins formed earlier, so avoid it by reheating only one portion at a time.
Can you reheat chicken twice?
No, chicken follows the same once rule, and any leftover chicken should be cooled and kept cold rather than put through another reheat.
Can you reheat soup twice?
No, soup follows the once rule, so portion it into single servings before it goes in the fridge.
Can you reheat rice twice?
No, rice follows the same once rule as other cooked food, and toxins that have already formed are not removed by reheating.
Why can’t you reheat food twice?
Each warm stage gives the food more time at temperatures where bacteria can grow, and reheating does not remove the toxins already formed, according to the Centre for Food Safety.
Is it safe to reheat food several times in a microwave?
No. The once rule still applies in a microwave, and the centre should reach 75 °C before you serve.
Can you refreeze leftovers after reheating?
Generally no, because the Centre for Food Safety says refreezing thawed food is generally not recommended.
How hot should reheated food be?
It should reach at least 75 °C at the centre of the food, which is the figure the Centre for Food Safety gives for chilled food served hot.
Does reheating food kill bacteria?
Reheating can kill the bacteria, but it does not remove the heat-stable toxins they already produced, so reheating does not make old food safe.
Bottom line: reheat once, to at least 75 °C at the centre, and reheat only what you will eat. The rest of the kitchen habits that make this easy are in the Zero-Waste Kitchen hub.
Sources
- Centre for Food Safety, Hong Kong: Heat-stable Toxins from Bacillus cereus and Staphylococcus aureus: Why Cooked Food Should Not Be Left at Room Temperature for Too Long
- Centre for Food Safety, Hong Kong: Food Safety Focus (109th Issue, August 2015): Incident in Focus
- US Food and Drug Administration: Are You Storing Food Safely?
- NHS: Food poisoning