What actually happens

When you heat food above 140°C, amino acids and sugars on the surface start reacting. They rearrange into new flavor compounds — and according to Harold McGee in On Food and Cooking, the reaction produces over 1,000 distinct flavor compounds in total. That’s why a raw chicken thigh tastes nothing like a roasted one — same protein, completely different molecules on the surface.

Why air fryers are good at this

Air fryers circulate hot dry air at high speed. Dry surfaces brown faster because water evaporates before the temperature can climb past 100°C. The fan accelerates evaporation, which means the surface hits Maillard temperatures sooner. That’s why air fryer chicken skin gets crispier than oven-roasted — it’s not magic, it’s faster moisture removal.

What blocks it

Moisture is the enemy. If food is crowded in the basket, steam gets trapped and the surface stays wet. That’s why every air fryer recipe says “don’t overlap” — it’s not about airflow for cooking through, it’s about airflow for browning.

The temperature window

Below 140°C: nothing happens. Between 140–165°C: slow browning. The reaction proceeds most rapidly between 150–180°C (300–355°F), and browning rate roughly doubles for every 10°C rise in surface temperature. Above 200°C: you start crossing into burning territory. The sweet spot for most air fryer cooking is 190–200°C.

Sources