I believe the rocket oven is one of the greatest technology innovations in the permaculture realm thus far, in part because of the vast range of applications. What are some other ideas for rocket oven use, and what sort of tweaks to the design would they require? I'm suggesting this thread be a general discussion of these ideas.
I'm interested in two in particular - a rocket oven roaster, for coffee or herbs. I love coffee and was disturbed to learn how much energy goes into roasting the beans. Right now we buy from Joshua Tree Coffee Company, which uses a special roaster that takes way less energy in the process. But I would love to figure out how to make a commercial size rocket oven roaster. I think the roasting process is long and low... and here's another thought - would a solar roaster be a better idea?
On the opposite end of the spectrum - a rocket oven kiln for pottery. That would need to be long and very high temp, from what I understand. So that would require a lot of attention to watch, but I think it would be worthwhile. I've been interested in learning pottery, but was really put off by the amount of heat required and the energy use that goes with that requirement. My pottery learning curve would probably be enough to heat a couple houses for a year, and that's kind of horrifying. hah! Could a rocket oven be made to create and withstand pottery firing temperatures? How could one feed it for hours at a time?
Paul's latest kickstarter - Paul Wheaton Rocket Oven Kickstarter- is probably the most exiting one for me thus far. I think this is because creating a working rocket oven is a really challenging idea for me, I probably wouldn't have figured it out on my own. Thank everyone for the work on this project, and for helping it get funded... I want that DVD. :-D
For reference, here is the quick video PW made about how the rocket oven works:
And here is the kickstarter video that is more of an overview of what a rocket oven is:
Here is an example of someone who built a home wood-fired kiln, and makes nice pottery with it. But fuel efficiency is what I'm looking for, and that's a combo of both the way it's fueled and heated, plus the ability to fire a decent number of pottery items at once. Here is what a kiln looks like:
HomesteadPottery's Wood Fired Kiln
And here's a simple brick one built by someone on Youtube:
As for coffee roasting - this is a wiki on it, and a visual showing the temps the coffee needs to get to: Coffee roasting Basically, it's a maximum of 437F/245C. could that be achieved with solar instead?
All thoughts, and new ideas welcome!
Be joyful, though you have considered all the facts. ~Wendell Berry
Jon and Flip Anderson have been building rocket ovens, kilns, and stoves for quite some time.
Their work concentrates on rockets made from universally available materials like mud, sawdust and manure.
Check out their website at rechoroket.com and this video at
I am especially impressed by some of the kilns they have built. Using simple mud rockets, they have fired parts for even better rockets, bootstrapping their way better tools.
Look in the photo albums on their site and you can find a project using rocket stoves to recycle plastic.
It required some decent temperature control,so it might offer tech useful for a coffee roaster.
The traditional wood fired kilns of Japan, the Anagama and Naborigama, are already very rockety. They work on the same principles. But what I think you are recommending is to seperate the rocket part from the firing chamber, and that would decrease effeciency greatly. Pottery has to be directly in the flames for hours or days. Source: is a potter for a living and has built five kilns, of which four were woodburning and one was propane. If you want more info, the site digitalfire and the book The Kiln Book have enough that you will be occupied for weeks.
I have already designed a rocket coffee roaster. I will provide plans for cost of printing and shipping once I work out the bugs and get it legally protected.