The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Gas fired backyard brick oven?

seanranney's picture
seanranney

Gas fired backyard brick oven?

I'm tossing around the idea of building a backyard brick oven, looking to be able to increase production of bread (and maybe the occasional pizza, but mainly for bread baking).  For a handful of reasons, I'd prefer to stay away from a wood fired oven, has anybody built one fired by gas?  I'm thinking of a barrel shape with a deck 2-3" up, with gas piping under the deck as well as along the sides to heat the barrel.  Couple of specific questions:

1. What sort of burners would I be looking at?  Fireplace log lighters?  How many BTUs would this produce?  I figure for a 24" x 48" deck I would need a total of about 60,000 BTUs, based on what I see commercial ovens using.  I'd install controls so I could control the temp of the slab separately from the air chamber so I don't burn the bottoms

2. Do I need a tall, curved ceiling, or is this tradition a function of having to build a fire and chimney up the smoke?  Could I get away with two flat masonry slabs 8" apart from each other?  I realize venting will come into play and I will need to figure that piece out.

I've seen a little bit of information on the gas versions, but mostly premanfactured units.  Id anybody has done this and has info on burners or how this works (or doesn't work) I'd appreciate it.

Thanks!!

OldWoodenSpoon's picture
OldWoodenSpoon

I read about the San Juan Bakery in San Juan Bautista, CA in "The Bread Builders" by Daniel Wing and Alan Scot.  I found this online Google Books copy.  My memory and the online copy don't match well, but only because some of what I remember does not seem to be in the book.  From memory I recall a large commercial oven in the wood-fired style, heated by a large "rose-bud" gas jet that was in a hinged gas line so it could be swung into the oven for firing and then removed from it for baking.  The online information does not disagree.  It simply does not include this detail.  I visited the bakery once, many years ago, so perhaps that memory has superimposed itself on the book.

In any case, the first couple of lines of the reference begin with "Not all ovens are wood fired....".  From that perhaps you can take encouragement.  From my own experience with wood fired ovens (an log lighters!), you will need something that produces substantially more BTUs than log lighters.

Best of luck

OldWoodenSpoon

seanranney's picture
seanranney

Thanks, I'll check out the book.  I also found Alan Scott's company on facebook and reached out to them. 

And yes, after a bit more research I've moved on to researching BBQ parts, some of those put out a good number of BTUs.  My oven woudl be a lot smaller than the one they describe in SJB!!

yozzause's picture
yozzause

Plenty of peel ovens were converted to either gas or fuel oil  and were the original traditional wood fired peel oven but fitted with a flame thrower.

i have used these commercially many years ago 

I have been very interested in building a Brick oven and would  have it so that i could use wood especially in winter and at other times and for convenience as well as fire restrictions use a venturi gas flame thrower from an LPG  bottle directed into the chamber, or a combination of the two. There was some good reading on venturi flame throwers but i will need to search it out.

There are some very good do it yourself venturi gas burners on you tube that i've just  watched 

 

Regards Derek

OldWoodenSpoon's picture
OldWoodenSpoon

Alan Scott passed on several years ago, may he rest in peace.  His son and daughter kept the company for a very few years, but as I recall they moved back to New Zealand and, as far as I know, the company now exists, in the US anyway, in name only.  If you hear from them on Facebook please post that fact back to the Wood Fired Oven forum here on TFL.  There may be many would be oven builders that would be interested in that item.

There was also an active thread going on here on TFL for some time exchanging plans for an Alan Scott style barrel oven built of brick, but I have not seen any activity on the thread recently.  I'm sure it is still on the Wood Fired Oven thread though, and a quick search would turn it up right away.  I believe that style is what you would want.

Best of luck in your endeavor.  I miss my WFO since I sold that house in the country, and my convection-only oven here in the rental in "town" is barely adequate.  I still turn out some decent loaves now and then, but without steam the results are not sterling.  Ah, those good old WFO days...  Sigh.

OldWoodenSpoon

seanranney's picture
seanranney

Thanks, I'll let you know if I hear from them.  Hope your decent loaves keep you happy!!

jbovenbread's picture
jbovenbread

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You have raised a number of issues with your question to TFL.  To put things in context I constructed a wood fired oven about ten years ago using the plans outlined in the book ‘Bread Builders’ but reduced in scale resulting in a deck of about 21” by 28” ..... a size I consider marginal as it will bake a maximum of 8 loaves (in pans) at one time.  I have also used a 90,000 btu roofing torch to get the temperature up a little when with a group of friends we baked 3 batches of bread totaling 17 loaves one afternoon.

The essential thing about a wood fired oven or retained heat oven is that the controlling factor is not so much the btu value of your burner, but the total btu value that is transferred to the thermal mass of your oven allowing you to bake the bread.  A 10,000 btu burner will do the same job as a 90,000 btu burner, but will take a lot longer to get the required heat into the oven.

I would suggest that you stick with a barrel shape, as opposed to a flat roof as I expect it will have the effect of providing a more even transfer of radiant heat to your baking than would a flat roof.

My biggest concern about your plans deals with the design and installation of gas or propane fittings.  I would STRONGLY suggest that you consult some professionals in the field before starting out on this endeavor.  As well, depending on where you live, there may be serious  legal and insurance issues that may have to be addressed.  You may be able to save yourself a lot of hassle, cost and frustration purchasing a gas fired, or dual fuel oven (generally produced for pizza I recognize) and modify it with additional cladding to provide you with the heating regime you are seeking, BUT this is a costly rout to go.

Finally, it you plan to construct your own oven I suggest that you keep it simple.   A roofing torch or some other type of burner placed in the oven to heat it up may not be elegant but will work.  If you plan to use the burner to continuously heat the oven you really don’t need to build in the thermal mass of a wood fired or retained heat oven.

Best of luck.  Let all of us know how you are making out.

 

seanranney's picture
seanranney

Thanks for the good points.  I'm in construction so have access to plumbers and have installed gas lines before, just not the internal working of an oven.  You bring up a good point on the retained heat type oven vs. continuous fired oven, I'll do some more research on that and see if what I'm thinking is really what I have in mind.  I'm more interested in bread than pizza so don't necessarily need the ability for it to get up to 800-900 degrees.

And, yes, the cheaper and simpler option is to buy a double oven off craigslist and install it in the garage.  But what fun is that?