24.3 Heat Transfer, Dry-Heat and Moist-Heat Cooking Methods, and Filipino Cooking Techniques
Key Takeaways
Conduction transfers heat by direct contact, convection by movement of air, water, or oil, and radiation by infrared or microwave energy.
Simmering takes place at about 85-96 °C, poaching at about 71-85 °C, and boiling at 100 °C at sea level.
Braising is a combination method in which food is first browned in fat and then cooked slowly in a small amount of liquid in a covered pan.
Microwaves heat food by making water molecules vibrate, so foods heat unevenly and need stirring and standing time.
Water boils at a lower temperature at high altitude, so foods cooked in water take longer to cook in places like Baguio.
Cookery principles and culinary vocabulary carry 10% of Foods and Food Service Systems. This section covers heat transfer and cooking methods; culinary terms and measurement are covered separately.
Modes of Heat Transfer
| Mode | How it works | Examples |
|---|---|---|
| Conduction | Heat moves by direct contact from molecule to molecule | Pan to food in sautéing; heat moving from the surface to the center of a roast |
| Convection | Heated air, water, steam, or oil circulates | Boiling, deep-frying, convection ovens (fans speed transfer, so temperatures are often lowered by about 10-15 °C) |
| Radiation (infrared) | Energy travels as waves from a hot source | Broilers, grills, toasters |
| Microwave | Electromagnetic waves make water molecules vibrate, producing heat inside the food | Reheating; uneven heating needs stirring and standing time |
| Induction | A magnetic field heats the cookware directly | Induction cooktops; need magnetic pans such as cast iron or magnetic stainless steel |
Cookware Materials
| Material | Features |
|---|---|
| Copper | Best conductor; usually lined because it reacts with acid |
| Aluminum | Good conductor, light, and cheap; reacts with acidic and alkaline foods |
| Stainless steel | Durable and non-reactive but a poor conductor alone, so often clad with aluminum or copper |
| Cast iron | Heats slowly but holds heat; adds some iron to food |
| Clay pot (palayok) | Slow, even heat for traditional dishes |
| Nonstick coatings | Less fat needed; avoid overheating empty pans |
Dry-Heat Methods
| Method | Description | Best for |
|---|---|---|
| Roasting and baking | Surrounded by hot, dry air in an oven | Tender meats, poultry, breads |
| Broiling | Radiant heat from above | Tender cuts, fish fillets |
| Grilling (inihaw) | Radiant heat from below | Pork, chicken, fish, vegetables |
| Sautéing (ginisa) | Small amount of fat, high heat, quick cooking | Vegetables, thin meat strips |
| Stir-frying | Constant tossing in a wok over high heat | Chopsuey, pancit |
| Pan-frying | Moderate fat, medium heat | Breaded fish, chicken |
| Deep-frying (prito) | Submerged in oil at about 175-190 °C | Lumpia, fried chicken |
Moist-Heat Methods
| Method | Temperature | Best for |
|---|---|---|
| Boiling | 100 °C at sea level, large rolling bubbles | Pasta, root crops |
| Simmering | About 85-96 °C, small bubbles | Soups, stocks, nilaga, sinigang |
| Poaching | About 71-85 °C, no bubbling | Eggs, fish, fruit |
| Steaming | Food above boiling water | Fish, vegetables, puto, siopao, rice (sinaing) |
| Pressure cooking | About 120 °C at higher pressure | Tough meats, beans, quick cooking |
Combination Methods
- Braising: brown the food in fat, then cook slowly covered in a small amount of liquid. Adobo and kaldereta use braising principles.
- Stewing: small pieces simmered in more liquid, as in menudo and kare-kare.
Traditional Filipino Techniques
| Term | Technique |
|---|---|
| Adobo | Braising in vinegar, soy sauce, garlic, and spices |
| Paksiw | Cooking in vinegar with garlic, often fish |
| Sinigang | Sour soup soured with tamarind, kamias, or guava |
| Nilaga | Boiled meat and vegetables in clear broth |
| Halabos | Steaming shellfish in their own juices with a little water or salt |
| Ginataan | Cooking in coconut milk |
| Kinilaw | Raw fish "cooked" in vinegar or calamansi; acid denatures protein but does not reliably kill pathogens or parasites |
| Daing and tuyo | Salted and sun-dried fish |
| Tinapa | Smoked fish |
| Tapa | Cured and dried or marinated meat |
Altitude Effects
Water boils at about 100 °C at sea level but at lower temperatures at high altitude, roughly 1 °C lower for every 300 m. In Baguio, about 1,500 m above sea level, water boils near 95 °C, so boiled and simmered foods take longer to cook. Pressure cookers solve the problem by raising the boiling point.
Effects of Cooking on Nutrients and Quality
- Water-soluble vitamins (vitamin C, thiamine, folate) leach into cooking water and are damaged by heat, air, and alkali.
- Minerals leach into water but are not destroyed.
- Fat-soluble vitamins are fairly heat-stable but oxidize with long heating in air.
- Protein digestibility improves with cooking, but very high heat lowers lysine availability through Maillard reactions.
- Starch gelatinization makes grains and root crops digestible.
- High-temperature frying and baking of starchy foods can form acrylamide; avoid overbrowning.
- Proper cooking destroys most pathogens and parasites.
Choosing a method: match the method to the food's tenderness and composition, the desired flavor and texture, the nutrient goals, and the equipment available. For low-fat diets, choose steaming, poaching, grilling, and baking over frying.
Testing Doneness
| Food | Doneness check |
|---|---|
| Meat, poultry, fish | Food thermometer in the thickest part, away from bone; poultry juices run clear, but a thermometer is more reliable |
| Fish | Flesh turns opaque and flakes easily with a fork |
| Cakes | A toothpick inserted in the center comes out clean; the top springs back when touched |
| Breads | Golden crust and a hollow sound when the bottom is tapped |
| Vegetables | Tender-crisp when pierced with a fork |
| Rice | Grains are tender and the water is absorbed |
| Custards (leche flan) | A knife inserted near the center comes out clean; overcooking causes syneresis and holes |
Carryover cooking: large roasts keep rising in internal temperature by several degrees after removal from the oven, so they are taken out slightly before the target temperature and rested. Resting also lets juices redistribute before slicing.
Holding cooked food: keep hot food at 60 °C or above until service, or cool it quickly for storage. Long hot holding lowers quality and vitamin content, so batch cooking in smaller amounts closer to service time is preferred in quantity food production.
A cook gently cooks eggs in water at about 75 °C without visible bubbling. Which method is this?
Boiling
Poaching
Simmering
Braising
How does heat reach the food when chicken is grilled over hot charcoal?
Mainly by conduction through water in the meat
Mainly by microwave energy
Mainly by induction from the grill
Mainly by infrared radiation from the coals
Why does nilaga take longer to cook in Baguio than in Manila?
Water boils at a lower temperature at high altitude
Water boils at a higher temperature at high altitude
Meat in Baguio has more connective tissue
Cool air prevents conduction through the pot
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