Preserving BTUs is what survival cooking is all about. An armful of sticks can burn up in a few minutes and cook you nothing, or it can burn for two hours and cook you dinner, sterilize your water, and heat your bath. It all depends on how much oxygen you can keep from getting to the flames while the wood burns. Initially I thought “rocket stoves” were a gimmick, aimed at draining the well meaning survivalist of some cash and little else, but now I’m sold. The StoveTec rocket stove you see here in the pictures is currently $118 on the StoveTec website, and on Amazon, with free shipping. It works killer, and will likely cook your dinner every night for years, in return for a handful of small dried branches you pick up from the ground. In a survival situation, you really have to be a fuel miser, and that is what you get with a StoveTec.
The rocket stove concept is a matter of physics. An open flame offers unlimited oxygen and burns fast and hot, which eats up your fuel before you can use the heat that is trapped within it. When you throttle down the flow of oxygen, the fire burns slower and colder, and as a result, the fuel last longer, allowing you to capture the BTUs thrown off by the burning fuel. If you try to boil a pot of water over and open flame made from an armful of sticks, the sticks will burn up way too quickly to boil the water. Within a confined space, offering limited places for oxygen to reach the flames, you will be able to boil the water. You can make a very basic brick oven that will do close to what you can do with this StoveTec, but it won’t be as controllable. For $118, I don’t know that you can beat this stove as a long term cooking solution for survival.
The StoveTec rocket stove allows you to stop down the flow of air to the flame to almost nothing. This model in our test is the two door type, made for both wood and charcoal, and they also have a one door type that is made just for wood. I got the two door because I feel like bags of charcoal are an easy and cheap survival fuel to store, and having the charcoal version doesn’t preclude you from using sticks, as you can see from the pictures.
My initial test was to boil water. It failed, because I hadn’t put enough fuel in the reservoir, and I had closed the fuel door, expecting to boil a couple gallons of water with just a handful of twigs. The StoveTec is a miser, not a miracle worker, so on looking at the manual, it seemed that they advocated mostly keeping the fuel door open for wood, and using the included feed ramp with the stove to push fuel in as it burns. The only difference between what you see in the manual and what you see in my pictures is that I realized that the best course is to block the fuel door as much as possible with the fuel, if you want to make your fuel last the longest. Using only fallen palm branches and sticks, less than an armful lasted over two hours.
In that two hours I boiled water for an hour, at a rolling boil, using the StoveTec special pot, and and cooked some chicken breasts in a stovetop oven I purchased separately. When I finally pushed the ends of the sticks into the fuel chamber and closed the fuel door most of the way to let it burn out, I put the water back on and it boiled for at least another half hour. I could have made chicken soup, cooked a roast, and sterilized 5 gallons of drinking water easily, with just that small amount of fuel. Did I say the StoveTec wasn’t a miracle worker? Maybe it is.
The important thing is to follow directions. The StoveTec comes with an aluminum pot skirt made to fit up to a decent size pot. If you adjust it properly, this keeps most of the heat in, and you won’t believe how fast food cooks. I bought the special StoveTec pot, which is another $59, and I think it is a worthwhile investment. The pot has an extra skirt welded onto it, and the skirt extends up the sizes to smoke diffuser holes. The burn isn’t really smokey once it gets going, but no matter what pot you use, cooking with the included pot skirt you can expect a dirty layer of carbon on the outside of your pot or cooker. I think the pot is a worthwhile investment, and I just ordered the StoveTec water urn.
If you use the pot skirt correctly, I think other secret is really to jam the fuel sticks in tight to the sides of the fuel door so that very little air can get past them to the flame. This keeps the fire from reaching a mini-raging inferno. And as you can see, I put a temperature probe into the stovetop oven and measured only 300 degrees. This was with flames licking up visibly from the hole, so though it may look like the fire was burning as hot as possible it wasn’t. The chicken didn’t burn. It was, however, coated with a smokey coating that not everyone would love, and I don’t know if this was due to using the oven for the first time, the type of fuel, or the cooker itself. I can’t recommend this particular stovetop oven for this application due to the bad taste, but we will revisit this in the future. There is a Camp Chef Dutch Oven with a similar cone in the middle that hopefully will work even better than this alumimum oven, and though it is more expensive (I can only find this Swedish product on Ebay right now for over $80 with shipping and for $65 from one US retailer), you are talking about a heavy cast iron Dutch Oven with shelves compared to a flimsy piece of aluminum made for backpacking.
My only warning with the StoveTec is in the way of safety. Obviously you can’t use any burning fuel appliance indoors if it doesn’t have a chimney to vent the carbon monoxide and smoke to the outside. This rocket stove can’t be used inside under any conditions. Also, if you use the fuel pushing method, make sure you don’t leave and that you keep pushing the backs of the sticks into the over. Otherwise the fire will creep out, as you can see in the pictures. The rest of this article is a photo essay on using the stove, so please take a look and read the captions. This is a great product and I already did some homework for you, so don’t let it go to waste. If you are serious about survival, $118 for an appliance that can turn any fuel into a life saving water sterilizer is just a no brainer. I hope you read this article early because they may already be sold out.