Understanding what can and cannot go in an air fryer requires understanding how an air fryer works.
To some enthusiastic food bloggers, the air fryer is an intuitive appliance that can cook anything and everything. To certain members of my family, it is an inscrutable black box that exist to take up counter space. (“What should I use it for?” they ask, prompting me to spam them with my own content.) The truth lies somewhere in the middle: The air fryer does a lot of things very well, but it is not without limitations.
Understanding what can and cannot go in an air fryer requires understanding how an air fryer works. I can’t speak for every model, but most air fryers, whether basket-shaped or toaster oven-shaped, are equipped with a heating element and powerful fan that sit above the food. The fan blows the heat around, whipping away moisture to create crunchy, crispy, and well-browned exteriors. It is not a fryer, but a tiny, souped-up convection oven, and some fare fares better than others.
Avoid drippy batters
In spite of its name, the air fryer is not a true fryer. It can crisp up a previously battered and fried item—be it yesterday’s Popeyes or a frozen dinosaur chicken nugget—but placing drippy, battered piece of raw chicken (or anything) into it will not yield the results you want.
The quick moving air will blow the batter right off, making quite a mess and leaving you with naked chicken, a splattered basket, and—worse case scenario—a gunky, smelly heating element.
Skip foods lacking in heft
Small, light foods will be buffeted about by the air fryer’s mighty winds. I’ve even seen toast move a couple of inches. Sometimes this isn’t a big deal (my toast was not damaged by a little buffeting), but it can be frustrating if, for instance, your delicate coating of crumbs or herbs gets blown off your chicken tender. (You should avoid air frying fresh herbs anyway—they have a tendency to burn.)
Pick foods with some weight to them, or at least ones that won’t be ruined by a little mid-cook movement, and avoid shielding foods with tinfoil, which is utterly useless in an air fryer because it won’t stay put.
Don’t choose foods that are too large
The air fryer is only effective if the hot air can circulate around the food, and items that cover all (or nearly all) of the tray prevent this from happening. Consider this tale of two pizzas: One mini and one “party.”
When I first acquired my six-quart air fryer, I was excited to air fry a Totino’s Party Pizza (one of my favorite frozen pizzas). Sadly, it did not go well: The pizza fit inside the basket, but just barely, and blocked the hot air from circulating while the top of the pizza was blasted with direct heat from the heating element. This resulted in overcooked, nearly burnt toppings and a doughy, soft crust. Given that nearly half of the Party Pizza’s appeal is its crispy cracker crust, this was disappointing.
About a week later, I tried air frying two mini (about four inches in diameter) pizzas from Trader Joe’s. The hot air was able to move and groove around the pizzas, and they came out perfect. (Moral of the story: Buy smaller pizzas, or chop the Party Pizzas up before air frying.)
Avoid deep dishes
Thick, layered dishes like casseroles or pies present a myriad of issues. Even if you find a pie or casserole dish that’s small enough to allow the hot air to properly circulate around the vessel, the lack of heating element at the base of the fryer means your top cooks a lot more quickly than the lower layer, resulting in cold, damp bottoms and soggy crusts.
Adding a glass or ceramic dish into the mix certainly does not help. As A.A. Newton explained in her piece about air frying pies, physics is not on our side here:
Anyone who’s taken an introductory physics course can see where this is going. (Although I barely passed mine.) Circulating air heats some things efficiently, but large amounts of wet stuff and glass—which many pie plates are made of—not so much. Baking a pie in an air fryer is like warming up a swimming pool by pointing a hairdryer at the surface: The top inch or two might heat up a little, but you can forget about the sides and bottom.
This is not to say that you should avoid air frying baked goods entirely. Just expect the bottom to be a little less done than the top. (That’s why this emergency cookie works so well: The contrast of the crisp upper crust and the gooey innards is divine.)
Pass on unflippable foods
There’s a reason most air fryers scream and beep at you to flip your food or shake the basket about halfway into your cook. Doing so exposes both sides of your food to the heating element, ensuring uniformly crisp exteriors and evenly warmed interiors.
Knowing this can help you adapt your favorite dishes to be air fryer friendly. If you simply must have an air fried pie, consider making hand pies, which aren’t so large that they block air circulation, and which can be flipped to ensure a crispy crust on all sides.
Avoid excess moisture
Air frying soup is a bad idea. The whipping winds splash liquid all over the place, which can cause issues with your heating element—and an unhappy heating element is a liability. A spoonful of water to keep vegetables moist while they roast is fine, but avoid adding more than that (for health and safety reasons.