My cousin got an air fryer for Christmas and immediately started drenching everything in oil. “It says fryer in the name,” she argued. Her fries came out soggy and smoking. The smoke alarm went off twice before she asked me what she was doing wrong.

She was using about ten times too much oil. Which is the most common air fryer mistake by a mile.

How an air fryer actually works

An air fryer is a small, powerful convection oven. A heating element at the top radiates heat while a fan circulates it at high speed. The moving hot air is what crisps the food — not the oil. The oil is just there to conduct heat into the uneven surface of the food so it browns evenly.

High smoke point oils only. Air fryers run at 350-400°F. Olive oil smokes around 375°F — if your recipe calls for 400°F, you’ll set off the smoke alarm. Use avocado oil, peanut oil, canola oil, or vegetable oil. They handle high heat without smoking.

Foods that need basically no oil

Anything already fatty: chicken wings, sausages, bacon, fatty cuts of meat. They render their own fat as they cook. Adding oil just makes them greasy.

Frozen foods (fries, nuggets, fish sticks): they’re already parcooked in oil at the factory. Light spritz at most.

Vegetables: a teaspoon of oil per cup of vegetables, toss to coat, season, into the basket. Enough to make the seasoning stick and the edges crisp.

My cousin’s fries are now crisp and the smoke alarm stays silent. One teaspoon. That’s all it took.