Which? uses cookies to improve our sites and by continuing you agree to our cookies policy

Deep fat fryers advice guides

How to get the most out of your fryer

By Matt Clear

Article 3 of 3

Find out how often you should change the oil on your deep-fat fryer, whether you can use solid fat instead of oil, and more handy tips with our guide.

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

Mary Berry famously labelled deep-fat fryers a menace that have no place in the home, sparking a row with Masterchef judge Greg Wallace. 

While deep-fat fryers can be a fast route to tasty fried food, they inevitably involve using lots of hot oil, so you do need to take care when using these appliances.

We explain the key things to look out for below to help you get the best out of using a fryer.

Which oils can I use in my deep-fat fryer?

Although your deep-fat fryer's instruction manual will recommend which oils are suitable for your specific fryer, these usually include vegetable, sunflower, sesame, groundnut, corn, soy, hazelnut and rapeseed oil. 

Most deep-fat fryers advise against using olive oil, butter or margarine, as they are unsuitable for cooking at high temperatures and will bubble over and smoke. Oils with high water content should be avoided, too.

How often should the oil be changed in a deep-fat fryer?

Manufacturers' advice varies from five to 25 uses, and it will depend on what you're cooking in your fryer. But it should definitely be changed regularly – on average every 8-10 uses – especially if you are cooking food covered in breadcrumbs. Always follow the advice given in the instruction booklet.

After cooking, and once the oil has cooled down, you should filter the oil with a sieve to remove any food debris such as breadcrumbs. Once you've filtered it, keep the oil in a sealed container until the next time you use it – unless otherwise stated in the instruction manual.

Changing the oil can be tricky with some fryers, as you might need to lift the whole fryer to pour the oil out. Our deep fat fryer reviews take into account how easy this is to do.

What do I do with the old oil from a deep-fat fryer?

Once the oil has been used several times, it needs to be disposed of very carefully.

Oil should never be poured down the drain – once cool, it needs to be poured into a sealed container (for example, back into an old empty oil bottle) and disposed of according to your local council's guidelines.

Can I use solid fat in my deep-fat fryer?

Although using solid fat isn't recommended for health reasons, it is possible to use it in some deep-fat fryers, so check the instruction manual to see.

For deep-fat fryers that can use solid fat, you should melt it in a saucepan first and then carefully transfer it into the fryer before turning on the fryer.

The next time you use the deep-fat fryer, make holes in the solid fat all the way down to the bottom of the fryer. This will allow any water trapped underneath the solidified fat to escape as steam while it's melting.

Always refer to the fryer's instruction manual for the exact process for melting solid fats, as it can differ between models.

What else can I cook in a deep-fat fryer apart from chips?

Many deep-fat fryers claim to be able to handle a wide variety of both fresh and frozen foods – including meat, fish, and even cakes and desserts in some cases. Always check the fryer's instructions before cooking, as sometimes extra preparation is required, such as drying the food with kitchen roll or covering it in breadcrumbs.

Do deep-fat fryers cause unpleasant smells?

Smells are a problem with deep-fat fryers. Many do have lids which will reduce the issue, but when the lid is opened cooking smells will escape.

Some fryers have odour filters help to reduce this problem, but they won't eliminate the smell completely. None of the fryers we've tested are odour-free.

How do I clean my deep-fat fryer?

By definition, a deep-fat fryer isn't going to be simple to clean, because it cooks using oil. Some models have removable dishwasher-safe baskets, lids or handles that you can also wash by hand in warm, soapy water.

Deep-fat fryers with non-removable bowls will have to be cleaned at the sink with soapy water. Always refer to the instruction manuals for guidance, and ensure the cable and plug are kept well away from the sink.

The hardest part of cleaning a deep-fat fryer is removing the used oil. You should only do this when the oil has cooled down – never attempt to remove hot oil.

A lot of steam comes out of my deep-fat fryer when it's cooking.Is that a problem?

During cooking, it's not unusual for steam or condensation to build up under the lid of the deep-fat fryer. Opening the lid can cause steam to rush out – so make sure you're not standing directly over the fryer when you do this.

Steam can also escape from around the edge of the lid during cooking, so make sure the fryer is positioned in a suitable place in your kitchen.

Is a deep-fat fryer safer than a chip pan?

The fire brigade recommends replacing chip pans with a fryer for safety reasons. A chip pan of oil, heated on the hob, can reach temperatures of more than 300°C, which can cause the oil to burst into flames.

Electric fryers are controlled by a thermostat which is designed to keep the oil at the right temperature to avoid it overheating and igniting, which makes them much safer. Most deep-fat fryers also feature a thermal safety cut-out system to stop it working if it gets too hot.

Other safety features include viewing windows so you can see the food while it cooks, cool walls to keep the outsides from getting too hot, and locking lids that prevent oil from splashing out while cooking and reduce the risk of spills if a fryer is knocked.

However, it's still very important to take care when using a deep-fat fryer. Make sure you keep the instructions to hand and follow them carefully to avoid issues.

What about low-fat 'air' fryers?

Air fryers, such as the Tefal Actifry and Philips Airfryer, offer a lower-fat alternative to traditional deep-fat frying. They use around one tablespoon of oil to coat food, and then blast hot air around the fryer to cook food. 

In our air fryer tests we found the results to be closer to oven-cooked chips than chips cooked in a deep-fat fryer. The best models produced tasty chips though, and can be less faff than a deep fat fryer.

To see our full, independent reviews of low-fat air fryers, head to our air fryer reviews.

SHARE THIS PAGE