Getting a crispy result in an air fryer without oil comes down to not overfilling the basket and brushing a thin layer of oil onto the surface of the food; when hot air can circulate freely around the food, moisture evaporates quickly and the surface browns. An overcrowded basket blocks that airflow, leaving food soft and steamed rather than crisp.
Cooking completely without oil is possible, but the result is usually less crisp; even a tablespoon of oil makes a noticeable difference on the surface. Aiming for "low-oil" rather than "no-oil" is a more realistic target for most recipes, and the difference is even more noticeable with breaded or battered food.
How full should the basket be?
Keeping the basket at most two-thirds full lets hot air reach every side of the food; an overloaded basket traps steam around the pieces at the bottom and keeps them from crisping. For larger batches, cooking in two rounds gives a better result than cramming everything in at once.
Shaking or stirring the basket once or twice during cooking helps the pieces underneath get their share of hot air too, and this step makes a visible difference with thinly cut foods like fries. Keeping the holes in the basket grate from clogging also matters for letting air circulate properly.
Why does preheating make a difference?
Preheating the air fryer for 3-5 minutes means food meets hot air immediately instead of slowly losing moisture in a cold space, which helps the surface brown faster. Food cooked without preheating usually takes a few extra minutes to crisp up.
The effect is even more noticeable with frozen food, since a cold surface releases moisture more slowly.
What temperature should you use?
For most vegetables and frozen items, 190-200°C strikes a balance between cooking the inside and browning the surface; lower temperatures cook food through without giving it any crispness. For thicker pieces, lowering the temperature slightly and extending the time helps the inside cook without burning the outside.
Checking and stirring the basket halfway through cooking gives a more even colour.
What's the right way to use oil?
Brushing or spraying a thin layer of oil onto the surface, rather than pouring it on directly, uses less oil and gives a more even crisp; a thick layer of oil can drip to the bottom of the air fryer and start smoking. For breaded or crumbed foods, this thin layer of oil gets close to the crispness of pan-frying.
Choosing a high-heat oil instead of olive oil also cuts down on smoking.
How do you clean the air fryer basket and parts?
The basket and tray should be washed in warm soapy water after every use, with any sticky residue soaked for a few minutes to loosen it; dried-on oil can cause a smoky smell the next time you cook. The heating compartment underneath should also be wiped with a damp cloth from time to time.
Scrubbing the basket's non-stick coating with a metal brush or steel wool scratches it, which makes it harder to clean and reduces how crisp food turns out.