To deep-fry means to cook food by completely submerging it in very hot oil or fat. Unlike pan-frying, where food sits in a shallow layer of oil, deep-frying means the food floats and bubbles in deep oil, cooking quickly and evenly on all sides.

The intense heat creates a crispy, golden-brown coating while cooking the inside. French fries, chicken nuggets, and donuts are all deep-fried. The hot oil seals the outside of the food almost instantly, which is why deep-fried foods have that distinctive crunchy texture.

Deep-frying has been used for centuries across many cultures. Japanese tempura, Southern fried chicken, and Mexican churros all rely on this cooking method. The technique requires careful attention: oil that's too cool makes food greasy and soggy, while oil that's too hot burns the outside before the inside cooks through.

Restaurants often use special equipment called deep fryers, but the method can be dangerous at home because a large amount of extremely hot oil can cause serious burns or fires if mishandled. Deep-fried foods taste delicious but are typically high in fat and calories, which is why they're usually considered occasional treats rather than everyday meals.