Cooking Food

Why is food cooked?  How is heat transferred?

Food may be contaminated with harmful microbes that can cause disease. The high temperatures involved in cooking brings about chemical changes in food and kills these microbes. Cooking also makes food easier to digest and improves the food’s appearance, texture and flavour.

These are a few examples of ways to cook food, and notice that all of these methods involve heating the food to a high temperature:

  • Baking
  • Boiling
  • Steaming
  • Grilling
  • Frying

During cooking, heat is transferred from the source of heat to the food through conduction (e.g. grilling steak on a grilling pan sitting on a stove), convection (e.g. running cold water over frozen food to speed up thawing process) and/or radiation (roasting marshmallow over fire).

Check out the resources below to learn more why food is cooked and how heat is transferred (conduction, convection and radiation).

More Information:

OCR Food preparation and cooking

BNF Food processing

AQA video: Sauce making and methods of heat transfer

AQA video script: Sauce making and methods of heat transfer

BNF presentation: Heat exchange

Meat and teachers’ notes: How does it cook

EUFIC: Why do we cook our food and what happens when we do?