Cooking is all about using heat to transform raw ingredients into something delicious and safe to eat. Heat moves into food in three main ways: conduction, convection, and radiation.
Conduction happens when heat moves through direct contact. Imagine a chicken breast sizzling in a hot pan—the heat travels from the burner to the pan, then straight into the food. Metal pans work best for this because they transfer heat efficiently, while glass, ceramic, and air are slower to conduct heat.
Convection happens when heat moves through air or liquid. As the air or liquid nearest the heat source warms up, it rises, and cooler parts sink to take its place. This gentle movement keeps heat circulating—like in a pot of simmering soup or a convection oven with a fan.
Radiation is heat that travels through waves of energy. When those waves hit the surface of food, its molecules start to move faster and heat up. Charcoal grills, broilers, and toaster coils give off infrared radiation, which browns the outside of foods. Microwave radiation cooks with high-frequency waves that penetrate into food, heating it much faster.
Understanding how heat cooks food helps you become a more confident and effective home cook. Knowing which type of heat you’re using—and how it moves—can guide your cooking choices. For example, you’ll know why preheating a pan is important for a perfect sear (conduction), why roasting vegetables in a convection oven gives them crisp edges (convection), or why broiling a steak browns the top so quickly (radiation). When you understand how heat works, you can adjust your techniques, avoid common mistakes, and get better, more consistent results in your own kitchen.
