7 foods you should think twice about before reheating in the air fryer – and what to do instead

Air fryers are popular kitchen appliances in many UK homes, thanks to their ease of use, energy efficiency and ability to cook crispy, golden-brown food more quickly than ovens.

Using an air fryer to reheat leftovers is also a simple, cost-effective way to reduce food waste and deliver convenient meals for busy lifestyles. Some premium models, such as the Philips 3000 Series NA342/09 and Ninja Foodi MAX AG551UK, even come with dedicated reheat settings.

However, not all foods are suitable for reheating in the air fryer. Doing so can lead to health hazards, overly dry textures, stubborn messes and poorer results than you'd get from other kitchen appliances.

To help you get the most out of your leftovers, we've rounded up the foods to keep out of the air fryer, along with reheating tips and trusted advice from the Food Standards Agency (FSA). 

7 foods you should think twice about before reheating in the microwave: we also reveal the foods that lose their flavour, texture – or worse, pose health risks – in the microwave

What foods should you think twice about before reheating in an air fryer?

1. Rice

While some people do reheat rice in an air fryer – usually using a suitable container and a splash of water – we don't recommend it. The appliance's rapid hot air can quickly dry out or harden the rice.

Rice also needs particular care when reheating, so we'd recommend using a method that makes it easier to heat it thoroughly and evenly. 

How to reheat rice

Whether it's safe to reheat rice depends on how it was handled, stored and cooked initially.

Rice can contain spores from a type of harmful bacteria. If cooked rice is left out at room temperature, the bacteria can start growing again from the spores, multiplying and producing toxins that cause food poisoning. Reheating will not get rid of these toxins.

If you've cooked too much rice and don't want to use it all straight away, the FSA advises cooling it down as quickly as possible – ideally within one hour – and then storing it in the fridge.

Leftover rice that has been covered and stored correctly in the fridge should be used within 24 hours and reheated until it is steaming hot throughout with no cold spots.

A microwave is one of the quickest appliances for reheating rice. Simply place the rice in a microwave-safe dish, add one to two tablespoons of water to help it remain moist and heat until it's piping hot.

Alternatively, you can use one of the best rice cookers from our expert tests to reheat rice, but only if you use the cook or steam modes – the keep warm mode doesn't bring it to a high enough temperature. To stop it drying out, add a splash of water.

The FSA also recommends taking extra care when reheating takeaway rice. This is because some takeaways pre-cook rice and reheat it before serving, but you should avoid reheating food more than once.

Is last night's takeaway on the menu tonight? We reveal the best ways to reheat your takeaways for the tastiest results

2. Saucy dishes

Popular midweek dinners such as spaghetti bolognese, beef stew and chicken curry can be reheated in an air fryer if you put them in a suitable ovenproof container. However, a microwave is likely to be a more effective option.

As the hot air circulates inside the air fryer, loose, saucy dishes tend to splatter, creating messes that can be difficult to clean.

An air fryer's circulating hot air is better suited to foods you want to crisp up – for example, layered dishes such as lasagne and pasta bakes. Reheating them in a suitable ovenproof dish can help warm the filling while crisping up the topping. As with all reheated foods, make sure they are piping hot all the way through before serving.

How to reheat saucy dishes

For liquid-rich leftovers, using a microwave or hob is often faster and delivers a more even heat distribution.

Microwaves are ideal for reheating saucy curries, pasta and noodle dishes. However, they can leave cold spots where bacteria survive, so it's important to stir halfway through and make sure the food is piping hot throughout before serving. 

If you're looking to reheat curry sauces and other liquid foods, the hob is another good choice. However, you need to stir frequently to prevent sticking, uneven heating or burning, particularly with thick sauces.

If you find sauces have thickened in the fridge, try adding a splash of water or stock to loosen the consistency and stop them from sticking to your pan.

3. Soup

Soups and broths don't usually reheat well in your air fryer. Even if you use a suitable container, liquids can spill or splash inside the appliance, creating mess and potentially reaching areas that are difficult to clean.

A microwave or hob is likely to be a simpler and more effective option.

How to reheat soup

A microwave is a convenient choice for reheating soup, with the best microwaves from our independent tests delivering reliable results.

Soup can become very hot around the edges while remaining cooler in the centre, so stir it at intervals during reheating and make sure it's piping hot throughout before serving.

Alternatively, reheat soup in a saucepan on the hob, stirring regularly as it warms. Some soup makers also have a reheat function, so check your appliance's instructions.

Make your own scrumptious soup with our expert pick of the best soup makers

4. Delicate fish fillets

An air fryer's rapid circulating heat can quickly spoil leftover fish, making delicate fillets tough, dry and rubbery.

Air fryers can also easily overcook thin pieces, burning them at the edges before the centre warms up.

Breaded or battered fish can fare better in an air fryer, as the circulating hot air can help restore a crisp coating.

How to reheat delicate fish

Gentler reheating methods work best for delicate fish, helping to maintain the soft and flaky texture.

Fishmongers Fresh Fish Daily recommend slowly reheating fillets in a low-temperature oven – maximum 170°C. Before serving, always check the fish is piping hot throughout.

Unless the fish is breaded or battered, you can also wrap it in foil to retain moisture throughout the reheating process, adding a splash of water if you're worried about your fish drying out.

Mackerel, sardines or salmon? Discover the top tinned fish for omega 3s

5. Large or dense portions of food

Air fryers can be useful for reheating smaller portions, but they're less practical when you're warming a large quantity of food or a particularly thick or dense dish.

Air fryers have limited cooking capacity, holding between 600g and 2.3kg of food. Overfilling the basket can restrict the circulation of hot air, while thick portions may become hot at the edges before the centre has warmed through.

How to reheat large or dense portions of food

If you're keen to keep large dishes – such as lasagne and cottage pie – intact, an oven is likely to be a better option.

Use a food thermometer to check your leftovers have reached a core temperature of at least 75°C (165°F) for 30 seconds – or check your food is steaming hot throughout before serving. This helps to eliminate harmful bacteria that might have developed since initially cooking.

If you're using an air fryer, try cutting food into smaller pieces to help it reheat more quickly and evenly. To find a model suited to your household size and mealtime needs, check our independent air fryer reviews, where we uncover each appliance's true usable capacity.

Air fryers vs ovens: we compare energy usage, costs and – most importantly – the cooking results

6. Lightweight foods and loose toppings

Air fryers use powerful fans to circulate hot air, which means lightweight foods and loose toppings can easily blow around the basket.

Tortilla wraps, for example, can lift up, while the top slice of bread on a toasted sandwich may take off if it isn't secured. 

You should also take care when using foil or paper air fryer liners, as these can fly up into the heating element, potentially burning or catching fire.

How to reheat lightweight food

To stop loose toppings blowing around the air fryer basket, make sure they're securely in place or weighted down with other food beforehand.

Otherwise, you may find it easier to reheat lightweight foods in a frying pan, under the grill or in a microwave.

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7. Some vegetable dishes

Reheating leftover roast vegetables, such as root veg and potatoes, in an air fryer is an excellent way to give them new life, as the circulating hot air helps to restore some of the crispiness lost during refrigeration.

However, not all cooked vegetables should be reheated in the air fryer. Boiled peas and green beans, for example, can easily dry out or shrivel up.

Lightweight leafy greens, such as spinach and kale, can also dry out quickly or blow around the air fryer basket.

How to reheat vegetables

To retain the moisture in cooked vegetables instead of crisping them up, a microwave is the perfect choice. Leafy greens can also be reheated in the microwave, or in a covered pan, with a splash of water to keep them moist.

Alternatively, to revive the roasted flavour and crunchy texture of root veg such as carrots, try tossing them in a little oil and herbs before reheating in the air fryer.

Are air fryers the best and cheapest way to cook vegetables? We've compared appliances to find out which can save you money and benefit your health

What foods are best reheated in an air fryer?

Air fryers are brilliant at reheating foods with a crispy, battered or breaded exterior, making them a far better choice than microwaves for preserving crunchy textures and preventing soggy leftovers.

Chips and roast potatoes, for example, can be easily reheated in an air fryer for the crispiest, fluffiest and most delicious results.

Air fryers can also effectively restore the golden, flaky texture of pastry dishes, such as pies, and revive the crispy crusts and perfectly melted cheese of leftover pizza slices.

Discover more air fryer cooking tips you'll actually use – tried and tested by Which? air fryer fans

How to store and reheat leftovers safely

Taking extra care when storing, cooking and reheating meals is essential for reducing the risk of food poisoning.

Leftovers should always be used within two days of initially cooking. If you're not going to eat all of the food you have cooked immediately, the FSA advises cooling it as quickly as possible and then storing it in the fridge. You can also freeze and reheat leftovers, provided they haven't already been reheated.

Never put piping hot food in the fridge as this can warm up the inside of your appliance. This not only compromises the freshness of other items – which need to be kept at a stable temperature – but it also forces your fridge freezer to work harder to cool down, increasing your energy bills. Discover more of our tips in 10 ways to say on energy bills.

No matter what kitchen appliance you use to reheat your leftovers, always check that the food is steaming hot throughout to kill harmful bacteria that may have grown since it was cooked.

When using an air fryer, avoid overloading the basket so the hot air can circulate and reheat your food thoroughly.

Shaking the air fryer basket halfway through also prevents items such as chips from sticking together, delivering evenly cooked results and achieving a deliciously crispy finish on all sides.

Reheating times will vary depending on the type of food, quantity and air fryer model. Check the manufacturer's instructions for recommended times, temperatures and settings – and keep a close eye on your food as it reheats to ensure it does not burn.

Which food containers can you put in an air fryer?

Ovenproof containers are generally safe to use in air fryers. This is because air fryers are essentially compact, high-powered convection ovens, so most of the same cookware guidelines apply. 

Materials that are safe to use in an air fryer include:

• Ovenproof glass Brands such as Pyrex are usually safe to use in the air fryer, but they must be tempered and labelled as oven-safe.
• Ceramics and stoneware Much like glass dishes, they must be labelled as oven-safe. Never move a cold ceramic dish straight from the fridge into a pre-heated air fryer, as the thermal shock may cause it to crack.
• Food-grade silicone Oven-safe silicone moulds are highly heat-resistant and perfect for air fryers.
• Metal Aluminium baking tins, stainless steel bowls and aluminium foil – when weighted down so they don't fly up into the heating element – are safe to use in an air fryer.

Reusable and single-use liners are also widely available to fit most air fryer baskets, preventing the food from sticking to the base and making post-meal clean-ups easier. Find out how silicone, paper and other reusable sheets compare in our guide to air fryer liners tested.

However, when preparing to use any food container in the air fryer, you must check both the label and manufacturer's instructions for your specific model to ensure it can withstand the rapid circulating heat.

You should also avoid using containers which include the following materials:

• Plastic Plastic containers can melt, ruin your air fryer and potentially release toxic fumes.
• Wood or bamboo These can warp, splinter or even catch fire in an air fryer.
• Paper Unless it's perforated parchment paper specifically designed for air fryers, avoid using any paper in your appliance, as it's a severe fire hazard.
• Non-ovenproof glass Standard glass or non-tempered bowls will shatter from thermal shock.

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