Fire is the original heat source. We’ve used it to cook our food for hundreds of thousands of years. In modern times, lighting a fire is relatively easy. We have matches, storm lighters, piezo lighters and more. These things are so ubiquitous that anyone can light a fire.
Over the past two centuries, we’ve also developed a number of flameless heat sources that we can use instead of fire. We’ll get to them soon enough. First things first!
The science of fire – and how to start one
Starting a fire is pretty straightforward. We need oxygen (air), heat and fuel (eg. wood or tinder).
Generating the heat can be tricky if you don’t have a lighter. Traditional ways have involved using tools to generate friction or strike sparks onto a flammable material.
Once we have a fire, the fun can begin!
Generating heat through friction 
Creating hot sparks with a fire steel
heat transfer
Getting the heat from your fire and into your food is the next step.
| Type of transfer | Definition | Example |
Conduction | Direct contact | Frying in a skillet |
Convection | Through moving air, oil or water | Roasting in the oven |
Radiation | Without contact | Light from hot coals |
All three forms of heat transfer occur to some degree in all cooking. It’s the proportion and energy of each that matters. Usually, one from of heat transfer is dominant in each step.
2. Heat is transferred from the pot to the water by conduction.
3. The water is then heated by convection as hot water moves away from the sides and bottom of the pot. This heated water interacts with cooler water until all the water in the pot is boiling.
we can facilitate the heat transfer
Use a heat transfer medium
Water (up to 100°C/212°F) and oil (above 100°C/212°F) are the most common.
Water 
Oil
Control the moisture level
Moist cooking results in a more even distribution of heat at temperatures around 100°C/212°F. We use moist heat for steaming, stewing and boiling.
Dry heat usually involves higher temperatures yielding crisp crusts, charred surfaces and new flavors.
Moist heat: Steaming dim sum 
Dry heat: Grilling vegetables
Choose the right material
The right cookware can make the difference between a successful dish and no meal at all. Knowing your materials is a good start.
Copper transfers heat very quickly. Requires experience for correct use. 
Aluminum transfers heat quickly and evenly, but may pose health risks when in direct contact with acidic foods. 
Stoneware absorbs heat and then releases it evenly. Can be damaged if heated or cooled quickly. 
Steel transfers heat quickly, but doesn’t accumulate it. Easy to use. 
Cast iron absorbs heat and releases it evenly. Easy to use. 
Glass transfers heat well, but does not store it. Can be damaged if heated or cooled too quickly.
