our low-tech, hi-tech rocket stove!
Ever heard of a Rocket Stove? Sounds like something out of a commercial… made of some state-of-the-art polycarbonate material that will surely cook up any meal at the rate of Speedy-Gonzales with just one touch of a button, right?
Well, in short, no… a Rocket Stove isn't this… as our Permaculture Manager Lindsay kindly explained to the residents, staff and a group of visitors to Kesho Leo.
The Rocket Stove that we were building, though simple in its make-up, is impressive in it's own right; demonstrating a much-needed improvement in efficiency over traditional cooking methods in a number of ways.
Most houses in Tanzania cook their food using the three stone method'a system of placing three medium sized rocks (to support the cooking pot) in a triangle shape that leaves enough space in-between each rock to place fuel wood.
This method, though much easier (initially) and accessible to use, loses a lot of heat (as the wood sends the heat in all directions), and can get costly with the amount of fuel wood being purchased.
Karibu (welcome) the Rocket Stove… from the outset, this thing looks like a big anthill with a pot shoved in on top. But in fact it's a lot more ingenious than it looks. This nifty invention has two major 'ups' on traditional cooking methods.
The first improvement can be found in its combustion chamber allowing wood to burn more cleanly and effectively, generating more heat into one direction and less smoke. The second is that because the pot is enclosed in a three-inch earthen wall, the heat is retained and distributed over a greater proportion of the pot, heating food and/or boiling water more efficiently.
So how do you make one of these? Easy, one banana stalk, clay, sand and a heat resistant material for a shelf ' yip that's it. The banana stalk is used to create a mold for the primary air intake, as well as an area where the fuel wood is inserted. It is cut into two pieces and placed at right angles on a clay base. When the banana stalk dries, it shrinks and is pulled out to create these air spaces.
The heat resistant material (e.g. sheet of aluminum) will be used as a fuel shelf leaving a space underneath for airflow. The clay and sand are mixed together (earthen) and built up around the banana stalks to produce a solid structure to support the pot. The size of the pot space is determined by the pot that is most used when cooking.
In the pot skirt (where the pot sits), air channels are cut into spiral shapes (in the earthen) continuing up the sides of the pot gap. This will serve to swirl the flame around the pot increasing its contact time with the pot surface. Smaller pots are able to fit into the pot skirt but will not be using the heat generated as efficiently.
Sounds great? Well, we thought so anyway, and also quite easy to make especially with help of a visiting group of teens from Holy Ghost Preparatory School (Pennsylvania, USA) ready to get their hands dirty. With a total of 14 workers (fws staff, Kesho Leo residents and enthusiastic visitors) many hands certainly made for lighter work.
We sifted, lifted, mixed, watered, stomped, packed, pushed, patted and built up this earthen mixture… Four hours later and it was done, Kesho Leo's first Rocket Stove!
Our piÃ¨ce de rÃ©sistance remains in its final stages of drying, ready to be used for many-a-day and hopefully years to come. Happy cooking Mama's and kids!