Cinder Block Rocket Stove
Hello readers. That was quite the little blogging break I took there. Like, about four months.
Partly the reason has been health issues (not Covid-19), and partly the reason has been a husband who has been working a lot more than usual (totally Covid-19). Even though it hasn’t been a productive fall for writing, it’s been a very productive fall for resilience activities. I’m excited to tell you about them, starting with the fun experiment of the cinder block rocket stove.
As I’ve written here and here, we cook mainly off-grid. In winter there’s the wood cook stove. In summer there’s the All-American sun oven and the camp stove, a ten year old dual-fuel Coleman. We have an electric kettle, a toaster oven and a crock pot as well, but I consider these to be convenience devices, mainly used for integrating the 9-5 life with the farm life as seamlessly as possible.
In short, they provide caffeine to the wage earner who gets up way earlier than I want to start a breakfast fire, and a ready hot meal at the end of the (now very few) days the kids and I spend away from home. Very nice. Not essential.
What is essential is that camp stove. I need it for meals on warm but cloudy or rainy days, for quick meals during the heavy work months, for eggs which provide most of our summer animal protein, for the scalding pot. It keeps the cooking heat out of the house. It keeps the wet feathers out of the house.
What if it failed? Some rust is apparent. What if I couldn’t afford or couldn’t get the gasoline, or maybe just forgot to refill the can? It will also run on kerosene, but boy is that stuff expensive.
As they say in prepper circles, two is one and one is none. Actually I remember my father saying that way before the bunker-hunkerers did (he's an engineer and an Alaskan outdoorsman for 45 years). I can’t count the times our butts were saved out on some icy river or windy mountainside because he had an extra pair of gloves/pair of pliers/aim-and-flame. Got to have a back-up for the essentials.
I do have a very nice fire bowl which is excellent for Halloween marshmallows and fancy grilled zucchini, but I rarely cook a regular dinner on it. It takes too long. It eats too much wood. It makes too much smoke. This is important: nothing I do with a fire is as efficient, carbon-wise, as the camp stove. Yes, even after accounting for the emissions of getting the ancient algae out of the ground, pumped all around and refined into gas of one kind or another. Your propane grill is less dirty than your charcoal one.
For my conscience, whatever I do with fire on a regular basis needs to be as efficient as possible. In addition, I like my backups to rely on the most basic materials and processes. It doesn’t get any more basic than small-diameter roundwood (a.k.a. sticks). A week doesn’t go by that I don’t say to my kids, “Don’t argue over a stick! We have 17 acres of sticks!” Efficiency + sticks = a rocket stove.
My first go was rather hastily assembled from things that were lying around, about half an hour before people wanted to eat. What can I say? That’s just how experiments are conducted here in the summer: crammed in around the edges of planting and harvesting and homeschooling. Yes, those are just salvaged cinder blocks, set together without mortar. It worked fine to fry and boil, but it smoked more than I preferred, which means the burn wasn’t very efficient.
The second iteration worked much better, because I followed the rocket stove rules more precisely. Imagine that! Follow directions, get good results! I find I’m always happier if I listen to the people who have already worked this stuff out.
Much less smoke was generated with an opening diameter : horizontal draw : vertical chimney ratio closer to the recommended 1:2:3. It also helped the comfort of the cook to orient the feed chamber away from my sweating body. About the only drawback is it takes a little longer to start than the camp stove, and it blacks the bottoms of the pots.
Summer waned, the heat broke and suddenly it was time to process poultry. I hatched a whole incubator full of new layers back in the spring, and they have grown up into some beautiful mongrels. Naturally, though, half of them are roosters, which adds up to 16 extra roosters. And my hens hatched a few of their own. And there are six geese. All in all, the fall poultry processing was looking a little daunting.
Thanks to Willy Peabody of Palmer, Alaska, I can dispatch a bird quickly and humanely. Thanks to Joel Salatin’s techniques, I’m an acceptably fast chicken cleaner. Thanks to Shannon Hayes of Long Way on a Little, I’m competent at breaking down and then cooking a bird (that's an affiliate link. Any proceeds go to cover the cost of this site first, and then to the Cool Effect). What I’m not so good at is the plucking. It always takes too long, and it pisses me off.
The problem is I never could get a good scald, because my pot has always been too small. The rooster fits. The water fits. But the rooster and the water do not fit together, if you take my meaning.
I bought a bigger pot, but it doesn’t sit as well on the camp stove. I was reluctant to lengthen the work time on a processing day, but I found it was easy enough to get the pot hot and keep it that way with the rocket stove. It only took a box of kindling and a few larger pieces to get through the whole process.
Yes, I got distracted in the middle by a funny-acting goose and let the fire burn down too low. You really do have to feed a rocket stove every ten or 15 minutes. But it didn’t take me any longer than in the past to pluck, which is good, considering it was a new process. And it was much less frustrating.
All in all, I would call the cinder block rocket stove a great success. It’s much quicker to get going than a bowl fire or wood-fired grill, uses a lot less wood to do the same job and doesn’t smoke me to death. I feel confident I could use it to fry, boil or grill anything quickly and easily enough, even under adverse conditions (such as a significant breeze).
I do eventually want something more permanent. There is a very fine pile of antique bricks up in the ravine which are just begging to become something useful. I’m still pondering the ultimate design and placement. Just the right height for regular meals is too high for scalding birds. It sure would be nice to be able to slap on a top and door, rake out the coals and use the residual heat to bake some cookies or a little pizza. I can see more experiments in my near future.
Do you cook with fire? What’s your favorite device?