With summer now a distant memory, it seems like a good time to reflect on a successful first few months for Wild Stoves. We now have a great range of products available on the website, and have enjoyed meeting many of you at festivals and events. And of course, we've eaten many a delicious outdoor-cooked meal!
One of the highlights of the summer was our trip to Buddhafield Festival near Taunton in July, where Jonathan held a series of workshops on 'Harnessing Energy from Wood Efficiently and Cleanly'.
The workshop focused on the ways in which stoves can be cleaner and more efficient than other methods of cooking, particularly open fires.
Open fires have been the main source of heat for most of human history. Not only are they portable and cheap, the fuel (wood) is easy to obtain. As well as heat for cooking, they also provide light and a social focal point. However, they are not necessarily the most efficient heat source.
What do we mean by 'efficient'? The process of burning fuel for heat has two stages; combustion and thermal transfer. 'Combustion' involves the breaking up of the long chains of hydrocarbons present in the wood. When this happens completely, the only products are carbon dioxide, water and ash. Incomplete combustion produces side-products such as carbon monoxide, tar particles, and benzene; more smoke and less heat. 'Thermal transfer' means how much heat is transferred to the cooking pot. The overall efficiency of the cooking process depends on both stages, both of which are dealt with inefficiently by open fires.
Greater efficiency is a good thing for several reasons. Firstly, the gases which are a side-product of combustion can be harmful to the health, as well as contributors to the greenhouse effect. Secondly, in many parts of the world wood is a non-renewable resource, so it's desirable to get as much energy from it as possible. In many developing countries, the majority of a family's money and time can be spent in buying and collecting fuel; so the more heat energy from each bundle, the better.
Stoves provide a more efficient means of cooking than an open fire. An insulated combustion chamber holds the wood gas in an enclosed heated environment, allowing the combustion to complete (which is why the rocket stoves have such thick walls).
Open fires are less efficient at combustion because they have the least oxygen where the heat is greatest, whereas gasifier stoves (like the Sierra) inject air into the combustion chamber; more oxygen means more CO2 and H2O instead of nasty carbon monoxide and hydrocarbons. When it comes to transferring the heat to your cooking pot, the stoves funnel heat directly upwards. A large surface area transfers heat more quickly (which is why a tiny bit of wood is all a storm kettle needs to boil the water for your tea!).
Hopefully knowing some of the science will make your next outdoor cooking experience even more exciting! If you're interested in this, keep a lookout on the Festivals & Workshops page for details of future workshops.
How was your summer? Upload your sunny outdoor cooking pictures and stories to our Facebook page , or email them to This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
