Food Preparation and Cooking Methods
Food Preparation and Cooking Methods tests your grasp of how heat moves into food and what that heat does to proteins, starches, sugars and fats. Questions ask you to choose a method for a given product, explain a fault, or predict the effect of a change in temperature or medium.
Heat transfer and method families
- Conduction: direct contact, as a pan to a steak or a baking sheet to pastry.
- Convection: moving air, water or oil, as in an oven, a boiling pot or a deep fryer.
- Radiation: grills, salamanders and microwaves.
- Moist methods: boiling, poaching, steaming, stewing, braising.
- Dry methods: baking, roasting, grilling, shallow and deep frying.
- Combination methods: braising and stewing - seal, then cook slowly in liquid.
What heat does
- Proteins coagulate between roughly 60 °C and 80 °C; overcooking contracts fibres and squeezes out moisture.
- Collagen converts to gelatin during long, moist cooking at 70–80 °C, which is why braising tenderises cheap cuts.
- Starch gelatinises at about 60–70 °C with sufficient water.
- Caramelisation occurs when sugars alone reach roughly 160–180 °C; Maillard browning needs amino acids plus reducing sugars and develops from about 140 °C.
Worked example
A tray of baked custard comes out curdled and weeping. Egg proteins set at 70–80 °C; an oven at 180 °C sets the outside first, the proteins contract and expel water (syneresis). Remedy: bake in a water bath at about 150 °C, pull the tray when the centre reads about 80 °C, and cool gradually. The reasoning links the fault to coagulation temperature, not to the recipe ratio.
Traps that cost marks
- Overloading a fryer, which drops oil temperature and produces greasy, pale food.
- Heating oil past its smoke point, causing off-flavours and fire risk.
- Salting pulses or stewing meat at the start when the brief calls for the end.
- Boiling vegetables in excessive water and leaching water-soluble vitamins.