Due to huge demand, Ernie and Erica drew up detailed plans for this a couple of years ago.
Ernie Wisner shows off his double chamber cob oven, which burns cleaner than a conventional cob oven. The second chamber is what gives the cleaner burn. And your cob oven ends up looking nicer, too (not all black in the front).
This cob oven uses some of the stuff from rocket mass heaters (or rocket stoves) for a cleaner burn. Ernie explains why this is not a "rocket cob oven".
A part that I edited out is where Ernie talked about sitting outside around the fire in a way where people stay warm and enjoy a fire without getting smoke in your face.
This video has pictures of other cob ovens and addresses some of the concerns about smoke and wasting of heat. Ernie explains how you start off with a two hour fire and end up with eight hours of cooking: starting with pizza, then moving on to breads, roasts, soups, rice, beans, and then yogurt and granola which cook at much lower temperatures.
Ernies also talks about the quality of bread from a cob oven vs. the quality of bread from a conventional oven.
Ernie addresses how he elected to not have a permanent roof over his cob oven.
Ernie's friend Kiko Denzer has a book on cob ovens that talks about this technique.
This video shows a huge flame coming out of the top.
Glenn Herbert wrote:8' deep is really huge! It sounds like it could easily bake all the bread for an entire village. Do you see a chance of actually using the full size of this? If not, I think it would be inefficient to heat it all up to use half or a quarter of the floor. I might consider modifying it to make the baking chamber shorter and converting the front portion to the reburn chamber connected to the chimney.You could probably even do it without significantly altering the existing except for a hole for the chimney, mostly adding new lining.
Is the exterior of the oven exposed so that you could add perlite-clay to it? I expect that would make a lot of difference to comfort.
scott romack wrote:This looks pretty cool but, why don't you put a feed tube in the back to the burn chamber?
This could double as the air intake and could self feed?
I'm thinking of a pizza party where you want to 800 deg. to be there for several hours..
brian haitz wrote:Hi guys, a couple of questions as we are going to build this oven soon, according tothe plans.
1 Considering the re-burn going into the exhaust pipe, does the pipe need to be stainless steel or will a copper pipe stand the heat?
2 I would like to tune the oven to heat up faster and cool down faster so it suits our small family needs better. To bake about two pizzas and one bread Will take about an hour and a half of baking time or a little less. Do you think an inch of thermal mass should be about right for that or will I risk it's cooling down too fast? I have obtained Chamotte Stones an inch thick for the base to go with it. Also what would you recommend as maximum installation thickness for such a setup?
3 in the book you mention that the exterior may not be treated in a way that the oven cannot breathe. How does simply linseed oiling it fair in that respect? Does that also inhibit breathability? And does polishing the exterior clay make a difference?
Thanks a lot!