How and when to preheat an air fryer to ensure even crisping

• Some air fryers have a preheat setting, some automatically preheat, and others require manual preheating.
• Consult the product manual to see if preheating is recommended for your air fryer model.
• Preheat your air fryer to the temperature called for in the recipe for three to five minutes.
• Visit Insider's Home & Kitchen Reference library for more stories.

Everyone knows that preheating your oven is crucial to baking success, but what about an air fryer? "Preheating maximizes both cooking and crisping results," says Purvin Shah, senior vice president of product development at SharkNinja. 

But knowing how and when to preheat can be confusing since it differs from model to model. Some air fryer models have a preheat setting while others don't, and some recipes call for preheating while others leave the step out altogether. "Preheating depends on the model," says Shah, and he points out that it even varies between SharkNinja air fryer models.

The safest bet is to check the manual since the manufacturer has tested the appliance thoroughly. "You should preheat an air fryer if the user manual instructs you to do so. Preheating only takes a few minutes, so you won't need to plan far ahead," says Shah.

Do you have to preheat an air fryer?

Air fryers are beloved for their ability to crisp up foods while using minimal oil. The gadget uses a built-in fan to push the heat around its interior and the food, cooking it evenly. This allows it to simulate deep-frying and high-heat roasting with minimal oil.

"Preheating circulates super-hot air around the air fryer," says Shah. This means that when you add the food it will start to cook right away and "remove moisture from your food's surface to give it that golden-brown, crispy finish."

Preheating isn't strictly necessary for air frying, and some models don't call for preheating at all. While the following tips are good to use as guidelines, defer to your model's manual.

When to preheat an air fryer

• The manual says to preheat: If your air fryer model's manual advises that you preheat before cooking, do it. Follow their instructions for preheating for the best results.
• A recipe says to preheat: If you're using a trusted recipe and it instructs you to preheat your air fryer, do it. You are more likely to achieve the recipe's desired outcome if you follow the instructions exactly.
• Crispy foods: If you're hoping for super crispy results, you generally want to preheat the air fryer. Shah points to examples like french fries (fresh or frozen) and chicken wings.
• When in doubt, preheat: If you're still unsure if you should preheat your air fryer, then go ahead and preheat. Since it's simply the appliance using one of its normal functions, it won't damage it to preheat and your finished dish will likely be crispier.

When not to preheat an air fryer

• The manual says not to preheat: If your model's manual specifically instructs you not to preheat, then don't do it. Some manuals simply don't mention preheating, which means it's not necessary but likely won't cause any issues if you choose to do so.
• A recipe says not to preheat: If it's a well-written recipe, the author will have tested it using their exact instructions. Preheating might alter the cook time and the results slightly, so it's best to follow it as written.
• Reheating leftovers: While you can certainly preheat before heating up leftovers, it's typically not necessary. If you're short on time, skip it.

How to preheat an air fryer

Before you switch on your air fryer, take a look at the manual for your specific model. Some air fryers have a preheat setting, some build the preheat time in and will automatically kick on after you program the temperature and cook time, and some instruct you to manually preheat using the air fry setting. Each method works equally well, so it's best to follow the instructions in your manual.

To preheat an air fryer, ensure that all removable parts like the basket are clean and dry and inserted into the unit. Then, following the instructions in your manual, either select the preheat setting or program in your cook time and allow the unit to automatically preheat. 

If your air fryer does not automatically preheat you can preheat it manually. Select the air fry setting and set the temperature called for in your recipe. "We recommend using a three-minute preheat for most models," says Shah. For larger and oven-style air fryers, preheat for five minutes.

Once the preheat timer has elapsed, add the food in a single layer (handling the basket carefully since it will be hot) and cook according to the recipe.

Insider's takeaway

For the crispiest possible food, consider preheating your air fryer. Check your manual to see if preheating is recommended for your model and if your unit has a preheat setting, preheats automatically, or must be done manually using the air fry setting.