Food tech s2 2025 exam revision
Hygiene and safety
Basics
Safe food temperatures
-15 freezer
5 - 60 temp danger zone
above 60
5 fridge
Cross-contamination
Organisation and skills
Measuring correctly
Kitchen safety rules
Following a recipe
Safe cutting technique
Scientific food processes
Cooking method
Baking
Dry cooking method
Baking is known as the cooking of food in an oven without the additional fat or oil
The colour change and creation of new flavours is due to maillard reaction and caramelization of the sugars
The heat transfer is known as convection. Convection is the transfer of heat inliquids and air that happens when the air molecules from a warmer area move to a cooler area
Poaching
Moist cooking method
Method of cooking delicate foods in a liquid at a temperature just below a simmer
Poaching allows for the structure of the proteins to stay preserved
You can use all different types of liquids such as water and stock when poaching
The heat transfer used when poaching is convection - movement of air and/or water
Steaming
Steaming is a moist cooking method
It is known as cooking in water vapor (steam) under varying degrees of pressure, there is so liquid movement to break up food
Steaming is a way to keep water soluable vitamins into the vegetables when cooking. Making it a healthier way of cooking
foods that work well for the steaming process is vegetables, dumplings, poultry and white fish
The heat transfer used when steaming is convection - movement of air and/or liquid.
Boiling
Boiling is a moist cooking method it is known as cooking food at 100 degrees celsius
The process involves immersing food into a liquid. The liquid is then heated. When at 100 degrees celsius the liquid will be bubbling vigourosly
Foods such as pasta, rice, sauce, vegetables are the main ingredients that are cooked at boiling point
The heat transfer for boiling is convection
Frying
Cooking food by total or part immersion in fat or oil that is heated to temperatures between 150 degrees celsius and 220 degrees celsius
Frying is seen as a dry cooking method: the reason being because the main ingredient when completing this method is oil also known as a fat
Types of frying are stir fry, shallow fry, deep fry
Stir fry is a fast way to cook food in a hot wok or pan
Shallow fry is cooking food in a small amount of fat being oil or butter in a shallow pan
Deep fry is submerging food in extremely hot oil and cooking it
Roasting
Cooking of food in an oven, open fire or other heat source
Roasting is a dry cooking method using the heat transfer of convection
The method of roasting allows for the foods surface to caramelize
The heat transfer used for roasting is convection and sometimes radiation
The food that is cooking will need to be coated in a small amount of fat or oil
Grilling
Fast dry method of cooking that uses intense heat radiated by an electrical element, a gas flame, glowing charcoal or an open wood fire
The heat transfer for grilling is radiation. Radiation is heat transferred by electromagnetic waves
Stewing
Long slow method of cooking where food is cut into pieces and cooked in the minimum amount of liquid, water, stock or sauce.
The food and the cooking liquid are served together
Stewed foods may be cooked in a covered pan o the stovetop or in the oven
The cooking process is a wet cooking method
Foods that best work for this process include goulash, minced beef, irish stew
Blanching
Method of partly cooking food by plunging it briefly into boiling water
Blanching is a moist cooking method
Heat transfer occurs in 2 modes convection and conduction
The best foods to blanch are Broccoli, tomatoes, cabbage, leafy greens
Science of food
Maillard reaction
The reaction that occurs when sugar or starch and a protein are present in a food and dry heat is applied, producing a golden brown colour
E.G baked bread, marinated meat
Coagulation
a from of nenaturation that occurs when there is a permanent change in the protein from a liquid into a thick mass a result of heat of addition of acids. The nenatured proteins for a new structure becoming firm and maintaining shape
E.G boiled egg, quiche
Dextrininsation
The process that occurs when a starch is exposed to dry heat the starch is broken down into dextrin, resulting in a change in colour to golden brown
E.G toast
Gelatinisation
The process in which starch granules absorb liquid in the presence of heat and thicken the liquid, forming a gel
E.G custard, lemon tart
Emulsification
Mixing two liquids that don’t normally combine, for example oil adn water. Some proteins act as emulsifying agents and hold the immiscible liquids in suspension
E.G vinaigrette, mayonnaise
Caramelisation
When sugar begins to decompose when exposed to high temperatures (190) using dry heat. Resulting in browning and enjoyable aromas such as those baked goods or roasting coffee
E.G toffee, caramelising sugar
Denturation
Describes a permanent structural change of the protein molecules in food. This can occur by the application of heat, mechanical action or addition of acids
E.G poached eggs, beaten egg whites, marinated meat
Aeration
The process of incorporating air into food products to increase the volume and create a light airy texture. Can occur by
- Biological ingredients e.g yeast
- Chemical ingredients e.g bi carb soda
- Mechanical actions e.g sifting & whisking