Cooking with Fuel, electricity and chemical reactions
The vast majority of us are used to cooking with fuel, electricity and – in some cases – chemical reactions.
Fuel allows us to transport and harness energy. It gives us the freedom to cook when and where we want. It’s not perfect, but it has allowed our ancestors to thrive for thousands of years.
Different fuels contain a different amount of stored energy. Solid biofuels like wood and cow manure have a lower energy density than liquid or gas fuels like butane or kerosene. This means you need less of an energy-dense fuel to get the same output as a given amount of regular fuel. After all, it’s easier to carry a small canister of butane instead of a few logs of wood when you go camping.
Fuels with the highest energy density tend to be fossil fuels. These fuels are essentially biofuels that have been concentrated over millions of years. Unfortunately, they also have downsides.
Get the most bang for your energy buck: Efficient use of your heat source
Dealing with hazardous byproducts
Cooking with fuel has one major downside – the components in smoke and fumes are hazardous. The most noteworthy of these are:
- Particulate matter – pollutes the air and harms the lungs
- Carbon dioxide – environmentally hazardous through acidification and trapping heat
- Carbon monoxide – odourless, potentially deadly gas
There are some good things we can do about it:
- Prevent it by using a different fuel (eg. natural gas, hydrogen or sunlight)
- Shift it elsewhere with a chimney and good ventilation (doesn’t prevent environmental problems)
- Burn the smoke/fumes (eg. cook with a rocket stove)
If we can generate or store enough of it in our off-grid location, we can cook with electricity. Although this is technically inefficient (a lot of energy is lost in transport and conversion), electric power lets us cook without the immediate hazards of an open fire.
All fuel-based cooking involves some form of chemical reaction. After all, the process of combustion is a pretty straightforward one. However, there are many other chemical reactions that produce heat. If you’ve ever mixed gypsum, you will have experienced such a reaction.
Another reaction that produces heat is the one that makes iron rust. This is normally too slow to notice, but by adding a mineral salt we can speed it up enough to produce usable heat. This is how self-heating emergency blankets, ration heaters and self-heating cup noodles work.
Making the most of it with Heat retention and pressure cooking
Once you’ve managed to produce enough heat to cook with, we want to get as much out of it as possible. No one wants to waste fuel.