From oven to air fryer

Why it converts this way

An air fryer is a small, very efficient fan oven: hot air circulates fast in a small space, so it cooks more at the same temperature. The rule of thumb used by manufacturers and cookbooks is to lower the temperature by about 20 °C (35 °F) and the time by 20%.

Indicative values

Every air fryer is different (power, basket size): use these values as a starting point and check doneness a few minutes early. For meat, always make sure it's fully cooked in the middle.

What it is, in one line

An air fryer is a small fan oven. There's no frying technology in it: there's a heating element and a powerful fan in a tight space, and the fact that hot air circulates fast around the food is all that separates it from an ordinary oven. That's where the conversion comes from: since moving air heats better than still air, the same thing cooks at about twenty degrees lower and in roughly a fifth less time.

The two rules that make the difference

Don't fill the basket. This is the mistake that ruins the result more than any wrong temperature: if the food is piled up the air can't get through, and what should have been crisp comes out steamed. One layer, with the pieces not touching — better two batches than one full one.

Shake halfway. The heat comes mainly from above, so the underside always lags: a shake halfway through mixes everything and evens it out. For potatoes and chopped vegetables, two shakes beat one.

A spoonful of oil helps, and contradicts nothing

Even cooking with air, a drizzle of oil changes the result: it carries heat to the surface and brings on the reactions that make the colour and flavour of browning. A spoonful on half a kilo of potatoes is enough, and it's still a tenth of what deep frying takes. Zero oil is possible but the result is closer to roasted food than to fried, and it's better to know that before being disappointed.

The two things never to put in: runny batters, which drip through the basket before they set, and light leaves with no weight on top, which the fan blows onto the element.

Below 140 degrees it's pointless

Below that temperature browning doesn't start, and the fryer is only doing a drying job: to warm something without cooking it, or to prove dough, a traditional oven at low temperature suits better. The air fryer is at its best between 180 and 200 degrees, the band where the outside dries and colours before the inside dries out.

Nearby tools

For the internal temperature of meat, which is identical in an air fryer, there is Meat temperatures, and for the match between degrees and gas marks Oven temperatures. For electricity use, which is one of its real advantages, Electricity cost.