Cooking techniques and heat transfer

Boiling, grilling, baking, stir-frying: each method uses heat in a different way, and changes the taste and texture of food.

Practise this lesson free (7 questions)

Preparing safely

Use the bridge hold (hand makes a bridge over the food; cut underneath) and the claw grip (fingertips tucked in, knuckles guide the knife) to cut safely.
Keep knives sharp: a blunt knife needs more force and slips more easily.
Use oven gloves, turn pan handles away from the edge of the cooker and wipe up spills straight away.

How heat travels

Heat reaches food in three ways:
Conduction: heat passes through a solid, such as from a hot pan into food.
Convection: hot liquid or air rises and moves around, carrying heat, as in boiling water or a fan oven.
Radiation: heat travels as infrared waves straight onto the food, as under a grill or in a toaster.
Most cooking methods use more than one of these.

Cooking methods

Methods can use water, fat or dry heat:
MethodHowExample
BoilingIn water at 100°C, with large bubblesPasta
SimmeringIn liquid just below boiling, small bubblesSoups, sauces
SteamingOver boiling water, in the steamVegetables (keeps more vitamin C than boiling)
Stir-fryingQuickly, in a little oil, over high heatVegetables and noodles
GrillingRadiant heat from aboveToast, fish
BakingDry heat in an ovenBread, cakes, jacket potatoes
Worked example

Why does steaming broccoli keep more vitamin C than boiling it?

  1. Vitamin C is water-soluble: it dissolves in water.
  2. When broccoli is boiled, some vitamin C leaks into the water, which is usually poured away.
  3. In steaming, the broccoli does not sit in water, so less vitamin C is lost.

Answer: Vitamin C dissolves in water; steaming keeps the food out of the water, so less is lost.

Key idea

Cut safely with the bridge hold and claw grip. Heat travels by conduction (through solids), convection (currents in liquid or air) and radiation (infrared, as in grilling). Steaming keeps more water-soluble vitamins than boiling.

Key words
Conduction
Heat passing through a solid, such as from a pan into food.
Convection
Heat carried by currents in a liquid or gas, such as in boiling water or a fan oven.
Radiation
Heat travelling as infrared waves straight onto food, as under a grill.

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Quick check

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Extra practice

2 more questions

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  1. Which knife skill holds a round food like an onion steady with the hand arched over it?

    1. The claw grip
    2. The bridge hold
    3. The pinch grip
    4. The fist grip
    Show the answer

    Answer: The bridge hold

    The bridge keeps fingers away from the blade.

  2. Heat passes from a hot baking tray into the bottom of a biscuit mainly by...

    1. Convection
    2. Radiation
    3. Evaporation
    4. Conduction
    Show the answer

    Answer: Conduction

    Heat moves through solids by conduction.

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Sources and references

Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.