Cooking Methods
This lesson covers the main cooking methods you need to know for AQA GCSE Food Preparation and Nutrition (8585, section 3.3). Cooking methods are grouped into three categories: water-based, dry heat and fat-based. You need to understand how each method works, which heat transfer it uses, and how it affects the nutritive value of food.
Classification of Cooking Methods
flowchart TD
A["Cooking Methods"] --> B["Water-Based"]
A --> C["Dry Heat"]
A --> D["Fat-Based"]
B --> B1["Steaming"]
B --> B2["Boiling"]
B --> B3["Simmering"]
B --> B4["Blanching"]
B --> B5["Poaching"]
B --> B6["Braising"]
C --> C1["Baking"]
C --> C2["Roasting"]
C --> C3["Grilling"]
C --> C4["Dry frying"]
D --> D1["Shallow frying"]
D --> D2["Deep frying"]
D --> D3["Stir-frying"]
style A fill:#8e44ad,color:#fff
style B fill:#2980b9,color:#fff
style C fill:#e67e22,color:#fff
style D fill:#c0392b,color:#fff
Water-Based Methods
These methods use water or water-based liquids (stock, milk) as the cooking medium. Heat is transferred primarily by convection through the liquid and conduction into the food.
Steaming
Food is cooked by the steam rising from boiling water beneath. The food is held above the water (in a steamer basket, colander or bamboo steamer) and does not come into direct contact with the liquid.
- Heat transfer: Convection (steam rises) and conduction (into food).
- Temperature: 100°C (the temperature of steam at atmospheric pressure).
- Effect on nutrients: Excellent for preserving nutrients because food does not sit in water — water-soluble vitamins (B vitamins and vitamin C) are not leached out.
- Suitable for: Fish, vegetables, dim sum, puddings.
Boiling
Food is fully submerged in water that is kept at a rolling boil (100°C, with large bubbles breaking the surface continuously).
- Heat transfer: Convection (water currents) and conduction (into food).
- Temperature: 100°C.
- Effect on nutrients: Greatest nutrient loss of all cooking methods. Water-soluble vitamins dissolve into the cooking water. If the water is discarded, those vitamins are lost. To minimise loss: use the minimum volume of water, do not overcook, and use the cooking water for sauces or gravy.
- Suitable for: Pasta, rice, potatoes, root vegetables, eggs.
Simmering
Similar to boiling but at a lower temperature — the liquid is just below boiling point, with small bubbles gently rising to the surface.
- Heat transfer: Convection and conduction.
- Temperature: 85–95°C.
- Effect on nutrients: Less nutrient destruction than boiling due to the gentler, lower temperature.
- Suitable for: Soups, stews, stocks, sauces, casseroles. Ideal for tougher cuts of meat where long, slow, moist cooking breaks down collagen into gelatine.
Blanching
Food (usually vegetables) is plunged into boiling water for a very short time (30 seconds to 2 minutes) and then immediately transferred to iced water to stop the cooking process.
- Heat transfer: Convection and conduction.
- Purpose: To partially cook, to preserve colour and texture (especially before freezing), to loosen skins (e.g. tomatoes), and to inactivate enzymes that cause browning and deterioration.
- Effect on nutrients: Minimal loss because of the very short cooking time.
- Suitable for: Vegetables for freezing, tomatoes (to remove skins), green beans, broccoli.
Poaching
Food is gently cooked in a liquid (water, stock, milk or wine) that is held at a temperature below simmering — the surface of the liquid barely moves.
- Heat transfer: Convection and conduction.
- Temperature: 70–85°C.
- Effect on nutrients: Good nutrient retention due to low temperature.
- Suitable for: Eggs, fish, chicken breasts, fruit (e.g. poached pears).
Braising
A combination method: food is first seared (browned) in hot fat, then cooked slowly in a small amount of liquid in a covered pot, usually in the oven.
- Heat transfer: Conduction (searing), then convection (liquid and steam in covered pot).
- Temperature: Typically 150–170°C oven temperature; liquid simmers at approximately 85–95°C inside the pot.
- Effect on nutrients: Some vitamin loss into the cooking liquid, but the liquid is usually served as part of the dish (as sauce or gravy), so nutrients are retained.
- Suitable for: Tougher cuts of meat (beef brisket, lamb shank), root vegetables, cabbage.
Dry Heat Methods
These methods cook food using hot air or direct radiant heat, without added liquid or fat (or with only a minimal amount).
Baking
Food is cooked by the hot air circulating inside an oven. No additional fat or liquid is added to the cooking process (though ingredients may contain fat).
- Heat transfer: Convection (hot air) and radiation (from oven walls/element), plus conduction (through the food).
- Temperature: Typically 150–220°C depending on the product.
- Effect on nutrients: Some B vitamin and vitamin C loss due to heat; however, no leaching into water.
- Suitable for: Bread, cakes, biscuits, pastry, fish, vegetables (e.g. baked potatoes).
Roasting
Similar to baking but usually involves coating food with fat or oil before cooking in a hot oven. This adds flavour and helps to brown and crisp the surface.
- Heat transfer: Convection, radiation and conduction.
- Temperature: Typically 180–220°C.
- Effect on nutrients: Some fat-soluble vitamins are preserved; some B vitamins are lost due to heat. Fat content of the food increases.
- Suitable for: Meat joints, poultry, root vegetables (e.g. roast potatoes, parsnips).
Grilling
Food is cooked by radiant heat from above (oven grill) or below (barbecue). High, direct heat is applied to the surface.
- Heat transfer: Primarily radiation, plus conduction (through the food).
- Temperature: Very high (surface temperatures above 250°C).
- Effect on nutrients: Quick cooking time helps retain some nutrients. Fat drips away from the food, making it a lower-fat method than frying.
- Suitable for: Steaks, chops, sausages, fish, halloumi, toast, vegetables (peppers, courgettes).
Dry Frying
Food is cooked in a non-stick pan without added fat. The food's own natural fat is used, or a very thin coating of oil spray.
- Heat transfer: Conduction (direct contact with hot pan).
- Effect on nutrients: Good retention; no added fat.
- Suitable for: Spices (to release flavour), seeds, nuts, bacon, mince (which releases its own fat).
Fat-Based Methods
These methods use hot fat or oil as the cooking medium. Fat can reach much higher temperatures than water (typically 170–190°C for deep frying), which creates a crispy exterior.
Shallow Frying
Food is cooked in a small amount of hot fat or oil in an open pan. The food is usually turned or flipped during cooking.
- Heat transfer: Conduction (pan to food via fat) and convection (within the oil).
- Temperature: 170–180°C (oil temperature).
- Effect on nutrients: Some fat is absorbed into the food, increasing its energy (calorie) content. Quick cooking helps preserve some heat-sensitive vitamins.
- Suitable for: Eggs, pancakes, fish fillets, burgers, onions, mushrooms.
Deep Frying
Food is fully submerged in hot oil or fat. The high temperature cooks the food quickly and creates a crispy coating.
- Heat transfer: Convection (hot oil currents) and conduction (into food).
- Temperature: 170–190°C.
- Effect on nutrients: The food absorbs significant amounts of fat, substantially increasing its energy content. Quick cooking retains some vitamins, but the high fat content is a nutritional disadvantage.
- Suitable for: Chips, battered fish, doughnuts, spring rolls, samosas.
Stir-Frying
Food is cut into small, even pieces and cooked very quickly in a small amount of oil at a very high heat in a wok or large frying pan, while being constantly stirred and tossed.
- Heat transfer: Conduction (wok to food) — the high heat and constant movement ensure rapid, even cooking.
- Temperature: Very high (wok can exceed 200°C).
- Effect on nutrients: Excellent nutrient retention — the short cooking time and minimal water mean very little vitamin loss. Only a small amount of oil is used.
- Suitable for: Vegetables, strips of meat, noodles, prawns, tofu.
How Cooking Methods Affect Nutritive Value