Preheat an air fryer for 2 to 5 minutes at the temperature the recipe calls for. Small baskets (under 4 quarts / 4 liters) are ready in 2 to 3 minutes; large baskets and oven-style models need closer to 5. If your model has a preheat button, it does exactly this.
Why bother preheating
The first blast of hot air is what sears the surface and starts the crisping. Food dropped into a cold basket spends its first minutes drying out instead of browning, which is the difference between crackly fries and pale, leathery ones. Preheating also evens out cooking: no cold-start zone means fewer half-done spots.
Do it right
- Keep the basket inside while preheating; you're heating the metal, not just the air.
- No parchment paper during preheat. With nothing holding it down, the fan can blow it into the heating element.
- Set the real temperature. Preheat at the temperature you'll cook at, not at max.
When you can skip it
- Long cooks: a 45-minute baked potato doesn't care about 3 cold minutes at the start.
- Delicate items: raw pastry and cheese-topped things sometimes benefit from a gentler start.
- Reheating leftovers: skip it; you want the inside warm before the outside darkens.
For everything you want crispy (fries, wings, breaded fish, vegetables) those 3 minutes are the cheapest upgrade there is.
The recipe remembers for you. Brasa shows each recipe's temperature before you start, so you can set the fryer to preheat while you prep. In cook mode, the screen stays awake and any "3 min" in a step is a tap-to-start timer, preheats included.
