4 October 2026

^{Photo: Philips}

 

You pull open the drawer and give the chips a shake. Most are turning golden, but you decide that it will take another few minutes and push the basket back into the air fryer.

When the timer sounds, you pick out a chip, let it cool and bite. The outside cracks, the middle is soft, and the potato tastes pleasantly roasted. You take another, strictly to check consistency. Then you wonder: how did this appliance achieve something normally associated with a bubbling vat of oil?

Here's how: an air fryer cooks food by circulating hot air through a compact chamber. The moving air delivers heat and helps carry water vapour away from the food’s surface. You could liken the cooking process to a “miniature hurricane”: movement is central to the machine’s success.

 

The Dutch origins of the Philips Airfryer

 

The air fryer is the brainchild of Dutch inventor Fred van der Weij. In a 2021 interview, he recalled starting the project in 2005 after discussing with a neighbour how to make good chips without deep frying. Some conversations with the neighbours prove more productive than others.

Working in Almere, Van der Weij experimented with prototypes made from wood and mesh before adding a removable basket to later versions. Philips licensed his technology and introduced its first Airfryer in 2010: a compact design intended to produce better chips, quickly and conveniently.

 

Air fryer versus fan oven

 

An air fryer is essentially a compact convection oven. Both use fans to circulate heated air. Their performance depends on chamber size, airflow paths and the arrangement of food.

In a basket model, openings allow air to reach food from several directions. An electric element supplies heat, while a motor drives the fan. Gaps and shaped surfaces guide the flow; heat radiating from the element can also contribute.

Different designs send air along different routes. Their shared principle is forced convection: actively moving heated air past food.

Oil transfers heat to food more effectively than air under typical frying conditions. It also has a much greater heat capacity per litre. An air fryer compensates partly by continually renewing the hot air beside the food.

The small chamber can be particularly effective for modest portions. Your full-sized oven still has its uses, even if it has recently been reduced to storing baking trays.

 

Your chips have not read the display

 

At the start of cooking, the chips are much cooler than the air around them. Selecting 180°C does not instantly bring the food to that temperature.The display shows a temperature setting, rather than how quickly heat reaches dinner. 

Engineers call the rate of heat transfer per unit of surface area “heat flux”. For a chip, it describes how much energy reaches each patch of its exterior each second.

Airflow helps determine that rate. Immediately beside the potato, air moves more slowly than it does farther away. This boundary layer offers resistance to heat and moisture transfer.

Faster airflow can thin and disturb it, improving heat delivery and helping water vapour move away. The temperature difference between air and food matters too. Two appliances at the same setting can therefore cook differently.

 

Before the crunch comes the water

 

A potato contains a surprising amount of water for something we mainly associate with carbohydrates. Some incoming energy warms the chips; some evaporates moisture at their surfaces.

Evaporation consumes energy and cools the exterior. A very wet surface therefore stays much cooler than the surrounding hot air.

The fan carries water vapour away, while vents release some humid air from the chamber. As the surface dries, its temperature can rise further.

Meanwhile, heat travels inwards. In freshly cut potatoes, starch granules absorb water and swell during gelatinisation, helping create the cooked interior. Frozen chips may already have been blanched or partially fried, so some preparation has happened before they reach your freezer.

The aim is a cooked centre and a dry exterior. Turning up the heat impatiently can produce dark edges around a middle that would appreciate a little more time.

 

How air fryers make chips crispy and golden

 

As the exterior becomes hotter and less wet, browning gathers pace.

Much of the colour and roasted aroma comes from the Maillard reaction, a network of reactions involving reducing sugars and amino groups, including those in amino acids and proteins. The same chemistry contributes to bread crusts and seared meat. There is no universal temperature at which it switches on. Its speed depends on heat, time, moisture and the food’s chemistry. Browning supplies colour and flavour. Moisture loss and structural changes help create a crust that fractures when bitten. A chip needs both; looking photogenic is only half the job.

Scientists can measure crunch partly by listening. In a 2025 chicken-nugget study (I'm not making this up), researchers recorded the sounds produced during mechanical cutting tests and compared the results with sensory assessments. Longer cooking and higher temperatures increased perceived crispness under the conditions tested. There are worse things to investigate than the acoustics of dinner, I guess.

 

Why overcrowding an air fryer leaves chips soggy

 

Now about those pale chips at the bottom of the basket: they have spent part of the cooking time sheltering behind their neighbours.

Packing the basket narrows air passages and shields touching surfaces. Some pieces receive less effective heating and drying. Shaking rearranges them, although it cannot fully compensate for overcrowding.

Accessories can affect airflow too. A solid liner may simplify washing-up while obstructing circulation through the basket, depending on its shape and the appliance.

Quantity also affects energy savings. A small portion can avoid heating a much larger oven. Several consecutive batches may erode that advantage. If you are feeding six people, the big oven may deserve to come off the bench.

So the next time you fish out that second, third, or fourth chip "strictly to check for consistency," you know exactly who to thank. Thanks to a productive chat over the garden fence and a miniature hurricane sitting on your kitchen counter, you get all the crispiness of a deep fryer with none of the oily guilt.