rocket oven vs cob oven

As the cob oven heats up, it pours smoke out the front. That smoke represents a lot of wasted heat going up into the atmosphere. So cooking a pizza is going to take three hours and a helluva lot of wood just to get up to temp.

Cob hates rain. The smallest bit of rain can destroy a cob oven. So most cob ovens require an elaborate shelter.

A cob oven is designed to be heated up for three hours and then it can be used for several hours of baking. This is due to the mass in the oven. That mass can weigh 500 to 2000 pounds. A rocket oven is quite light and portable versions can be moved by one person.

If a cob oven gets too cool, you have to stop using it so you can add heat. So if you are in the middle of baking a cake, you have pull your cake out, heat the oven, then put the cake back in. With a rocket oven, you just add more wood in the middle of the bake.

With a cob oven, you flood your neighborhood with smoke for three hours while the mass is being heated.
rocket ovens are so clean your neighbors probably won't know you are using it.

This problem with cob ovens has been solved with the double chamber cob oven. The smoke gets burned as it leaves the oven, but all that heat, unfortunately, escapes.

You cannot use a cob oven when open burning is banned, but you can use a rocket oven - because it is an enclosed burn.

Cob ovens are for outdoor use only - for obvious reasons. Rocket ovens were originally designed for indoor use, but work great outdoors too.

Thanks to Dan Ohmann of The Grass-fed Homestead channel for helping me with the editing:

Relevant stuff at permies:

music by Jimmy Pardo

Thanks to my patreon peeps for pushing me into making videos again:

Full Name
Bill Crim
Josh Phillips
wade L
James Tutor
Suleiman ALAQEL
Jocelyn Campbell
Jason Hower
Ash Jackson is The Scrollbard
thomas adams
Julia Mason
Dominic Crolius
David Ingraham
Miroslav Ultrama
Lisa Goodspeed
Bill Erickson
Keith Kuhnsman
Wayne Fajkus
Eivind W. Bjørkavåg
G Cooper
Dylan Butler

Permaculture Playing Cards

177 hours of Permaculture Design Course and Appropriate Technology Course

Better Wood Heat: DIY Rocket Mass Heaters 4-DVD set

Wood Burning Stove 2.0 4-DVD set

World Domination Gardening 3-DVD set

Permaculture Homestead Podcasts

Permaculture Design Course and Appropriate Technology Course

Rocket Mass Heater Workshop Jamboree

Sign up for my daily-ish email, or my devious plots for world domination

[abdulkadirthecarguy]

Plot twist you can do rocket oven with cob

[tgchism]

Some truth and exaggeration in the video. Here is my take. A Cob oven will smoke when first getting going as does a rocket oven. Both burn clean once they get going. A cob oven can reach full heat in about two hours give or take depending on size. With the right oven management you will get several items baked before you need to reheat the oven. A cob oven will retain heat for hours if not days depending on it's mass. It will bake pizzas amazingly fast on the high end. Roast or bake many items efficiently and quickly as it cools down and can even be used to dehydrate fruit on the low end of the heat cycle. Cob ovens have been used in homes in the past although with fire codes in most areas, you would most likely need a brick oven with proper exhaust. Both cob and rocket ovens have their advantages and disadvantages. Either can be ideal depending on your needs.

[KRscience]

Most people don't build cob ovens for day to day use. They're kind of a like a really neat campfire and are often used for social events. I personally love my cob oven and enjoy the company of people that it draws in. It also looks a heck of a lot better than a rocket oven!

[Dollapfin]

Why not a rocket cob oven? Just have the exhaust of a rocket stove go into the cob oven and exit thru the door? Seems like it would work great at a height of three and a half feet it sounds perfect. Then you get that mass hot for a good 3 hrs of baking from a short burn of thirty minutes or so.

[ncooty]

You guys produce some amazingly useful information and design improvements.

[paulwheaton]

please upvote, comment, watch to the very end, subscribe and then click on the bell!

[bradleyhayman]

I think you’re supposed to cook the pizza with the fire or coals still in the oven.

[justinw]

I'm thinking of building a rocket oven using mostly vacuum insulated glass jars. There will be a layer of something like insulated cob on the inside to protect the glass from heating and cooling too rapidly (regular soda glass doesn't do well with temp changes). We're talking a ridiculous amount of insulation, since the glass jars will be holding a vacuum of around 28" Hg.

I reckon if I do it right, I could get away with using very, very, very little fuel and it would heat up quite quick, because it would actually be fairly low mass and combined with simply ridiculous amount of insulation.

[JL-tmrc]

for a restaurant a cob oven will be better since a single firing allows you to use it for more than 24 hours

[gjh]

I have built a cob rocket oven. Its mass keeps the temperature stable, and the combustion is clean enough that food doesn't taste like smoke. It does take an hour to get up to temperature; when I build another one, I will put less mass in the floor. It is very much a showpiece - people love the dragon cookies and breads.

[Permisiepl]

Very informative video, love this sort of thing :)

[cattreesteve]

I really find the rocket oven for pizza interesting I would like to try one with 2 layers of 55 gallon drum.. thanks for your video and your time

[shidongxu]

What is the inside of maximum temperature on rocket oven? I estimate the baking temperature of the pizza.

[kallieespumante]

Hey Paul, Thanks for the video. Say a girl wants to build a cob rocket oven (cuz they are pretty and I have an overhang), would you recommend a chimney? I have read mixed things on that they create too much draft- and basically don't know who to believe lol.

[NnBadon-sepf]

hello i want a rocket mass heater is the oven the same