How and Why We Cook Food: Heat Transfer and Cooking Methods
Why do we cook food at all, and how does the heat actually get into it? Learn the reasons for cooking, the three ways heat is transferred, and the families of cooking methods.
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Free interactive practice on the decisions the assessment actually asks you to justify.
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Why we cook
A raw potato is hard, starchy and hard to digest. Cooked, it is soft, tasty and safe. Cooking changes food, but only once heat has found its way into it. This module covers the reasons we cook, the three ways heat is transferred into food, and the main families of cooking methods.
Heat transfer words
Heat reaches food in three ways. Learn them, plus one more useful word.
Three families of method
Every cooking method belongs to one of three families.
Match the heat transfer
- Conduction
- Convection
- Radiation
- Palatability
- Heat passing by direct contact, as in a frying pan
- Heat carried by a moving liquid or gas
- Heat travelling as rays with no contact
- How pleasant food is to eat
Under the grill
A grill browns the top of food using heat rays, with nothing touching the food. Which type of heat transfer is this?
- Radiation
- Conduction
- Convection
- Evaporation
Safety first
The most important reason we cook is safety: heating food destroys harmful bacteria. Cooking also develops flavour, improves texture, extends shelf life and adds variety to the diet.
Match the cooking method
- Boiling
- Steaming
- Roasting
- Shallow frying
- Cooking in bubbling water
- Cooking in the vapour above boiling water
- Cooking with dry heat in an oven
- Cooking in a little hot fat in a pan
Water-based methods
Which TWO of these are WATER-BASED cooking methods? Choose all that apply.
- Boiling
- Steaming
- Grilling
- Shallow frying
Boil an egg
Put the steps of boiling an egg into a sensible order.
- Fill a pan with water
- Heat it until it boils
- Lower the egg in carefully
- Simmer for the set time
- Cool it under cold water
Conduction, convection, radiation
Heat passing through a metal pan by direct contact is _____. Heat carried around by moving hot water or air is _____. Heat that travels as rays under a grill is _____. Cooking food in bubbling water is _____. Cooking food in a little hot fat in a pan is shallow _____.
Spot the dry methods
Tap the TWO dry cooking methods.
- Baking
- Grilling
- Boiling
- Steaming
In the pan
Frying an egg in a hot pan cooks the base first because the metal touches the food. Which heat transfer does the pan use?
- Conduction
- Radiation
- Convection
- Condensation
Pick the method
For each aim, choose the cooking method that fits best.
- You want to cook vegetables gently over boiling water while keeping most of their vitamins. Which method?
- You want to brown and crisp the top of a lasagne with fierce heat from above. Which method?
- You want to cook a whole chicken with dry heat all around it in the oven. Which method?
Explain the science
Explain why we cook food and describe the three ways heat is transferred to it.
- Give two reasons why we cook food
- Name the three ways heat is transferred
- Give an everyday cooking example of each