Firebrick Electric Oven Liner

[Wild-Yeast]

I've been researching oven stones variously known by a variety of names as a way in which stone hearth baking can be achieved in a normal home kitchen setup. I've used a pizza stone for many years and have come to realize some of its shortcomings. I am currently researching alternate setups that will affect a better initial heat for the spring rise.

One thought that hasn't disappeared is the idea of using halved low duty firebrick situated on steel frames to line an electric home oven. I was also thinking about a cast iron sub pan as a catchment for ice cubes to steam the crust through the first several critical minutes of baking.

I'd be interested in hearing from anyone who's thought about this subject or has worked on a similar project.

Best from Wild-Yeast

[Wild-Yeast]

Re: Firebrick Electric Oven Liner

The idea is for an oven shelf that can be positioned like a rack into the mid point of the oven for baking. Have to work out how the cast iron pan is mounted below the brick shelf.

Wild-Yeast

[Wild-Yeast]

Re: Firebrick Electric Oven Liner

A quick rendering of the idea using half firebricks:

[egalecki]

Re: Firebrick Electric Oven Liner

All I can add to your idea is what my oven repair guy said- if you have your oven elements under the floor of the oven, do NOT put your stone or anything else directly on the floor of the oven. He said it would burn up your element by trapping the heat right on top of it. This does go against what I've seen printed in at least one book, which said to put your stones/tiles/whatever right on the floor, but I think I'm going with the oven repair guy here. It's too much of a pain in the fanny to pull out the whole double wall oven to replace a concealed element! Not to mention expensive.

So, however you position your cooking floor, be mindful of the elements. Why does the steam part have to be cast iron? Couldn't you use a sheet pan? It would be easier to pull out to get the ice in-

I've tried quarry tiles on the rack, with a pan underneath, but my big pizza stone does better. My oven exhausts the steam, BTW, and so makes it all a bit of an exercise in futility. Nothing other than baking the bread in a cast iron pot does a good job of steam producing for my oven, though, which is why I'm building an oven.

Makes the case for really knowing what you need before you buy your appliances. Check wattage, steam retention possibility (or injection, some of them do that now), all of that, before you buy!

[Wild-Yeast]

Re: Firebrick Electric Oven Liner

Elizabeth,

Good points. The idea is to treat the brick layer as a shelf element (not shown in the render) and would have clearances on all sides. Cutting off the feedback system between a heating element and the temperature control is to be avoided (this applies to stone inserts too).

A large, thick, rectangular oven stone would be preferrable (and would be a whole lot easier to implement) but the thickest that I've been able to find is slightly under one inch and what's needed is on the order of one and one-half to two inches thick, necessary to act as a thermal reservoir to obtain proper "oven spring" (nearly as thick as in a real brick oven). My current stone is slightly over one-half inch and is marginal at best.

Building a FBO (Fire Brick Oven) is a solution but I feel that in my case its utilization would be low due to time constraints. The best solution, in my case, is a brick lined electric oven with steam injection but that's better left to a different thread and most probably to an entirely new house...,

Wild-Yeast

P.S. The cast iron fry pan works a treat even with an oven that vents. I stuff the external vent with a rag for the first five to seven minutes while the steam fills the oven then its removed so that the breads baking progress can be smelled.

[gjbingham]

Re: Firebrick Electric Oven Liner

I considered your situation for my own needs years ago. After building an oven and reading an incredible number of threads, I'd try two layers of brick, one above, one below.

You can buy hearth oven packages at King Arthur Flour and probably elsewhere, but you've already got a better plan, which would be much less espensive. You really want the radiant heat from above in addition to the floor that the pizzas sit on. You could buy two heavy duty pizza stones and put them on different racks and cook the pies between them, or use your design and do a similar application.

If you really want to go hog-wild, you could do sides and a back as well, but the benefit might be minimal. Regardless, I'd give your oven at least 30 - 45 minutes at 550 degrees to get the bricks really hot.

[Wild-Yeast]

Re: Firebrick Electric Oven Liner

The general theme that I've picked up on after reviewing many of the posts is that the bricks act as a heat reservoir to maintain a fairly constant oven temperature. An electric home oven doesn't really have any real heat reservoir so temperature excursions will be rather large when the bread is inserted into the oven. Additional heat requirements to vaporize water for steam only makes the situation worse. Specific Heat Capacity is the amount of energy required to raise the temperature of a material one unit of temperature (firebrick in this case). The larger the Specific Heat Capacity the more energy the material can hold, or for our purpose, the ability of the ovens lining material to maintain an even temperature. Now for some research on firebrick and its Specific Heat Capacity.

Wild-Yeast

[TDVT]

Re: Firebrick Electric Oven Liner

We have used firebrick splits (half thick@ 1.25") for some time in our commercial oven. I just set them side by side on the rack, 2 rows of 4. Since the oven is quite large there is open space on each side as well as a little in the back & front. They need to be preheated for at least 45min to 1 hr. I'm not sure what the upper temp limit of an unmodified electric oven is.

I didn't find our oven hot enough & moved outside to a Weber with charcoal, then switched to gas. Search "little black egg" for Villa Roma's excellent posts with the same thing or this one I posted.

I have had the best success with this set-up.

Ted

[Wild-Yeast]

Re: Firebrick Electric Oven Liner

Hi TDVT,

Great links and thanks! This adds an application "feel" to the list of design factors.

Electric home ovens may be Ok to bake bread but not pies. Pan au Levain (sourdough) bread is my focus and half bricks might just squeak by. I am sure that it won't cook 4 minute pizzas, as in "no way, no how"...,

Wild-Yeast

[chuckster]

Re: Firebrick Electric Oven Liner

Maybe this is a stupid idea (. . . that line has to be up there with "Hey watch this!" or "Wonder what this button does" ), but what if you disconnected the door lock for the cleaning cycle and bake the pizza at over 600 deg C.? Has anyone actually done this? Or haven't I had enough coffee yet? The stove must be designed with sufficent insulation to handle the cleaning temp, so why not bake?

Chuck

[TDVT]

Re: Firebrick Electric Oven Liner

Maybe this is a stupid idea (. . . that line has to be up there with "Hey watch this!" or "Wonder what this button does" ), but what if you disconnected the door lock for the cleaning cycle and bake the pizza at over 600 deg C.? Has anyone actually done this? Or haven't I had enough coffee yet? The stove must be designed with sufficent insulation to handle the cleaning temp, so why not bake?

Chuck

There's actually a hilarious story about defeating the self-clean safety for that very reason in the Ed Levine book "Pizza, a slice of heaven"

[Wild-Yeast]

Re: Firebrick Electric Oven Liner

Don't think I'll tread on defeating door interlocks.

I have a Kitchen-Aid and it will go to 599 degrees Fahrenheit though it doesn't seem to cycle on and off at that setting. It seems to do fine at 575 which is an acceptable upper limit. Pies in 8 or 9 minutes? Daniel Leader relates in his book, "Bread Alone" that he uses half firebricks in his home oven and is quite satisfied with the attendant "oven spring" they provide. So the original idea for baking sourdough on them seems to be on track. One question is whether to use mortar to cement the brick to an oven stone? Leader mentions that the patterns of the brick leave an impression on the bottom of the bread. Gave me the idea of grinding out a "personal brand" on the firebrick to give the bread a makers mark...,

Wild-Yeast

[gjbingham]

Re: Firebrick Electric Oven Liner

TDVT,
Funny, I was just thinking the same thing tonight. I figure that heat screen is in front of the glass for a reason when the oven's on clean. The very worst you could do is burn your house down along with all your earthy belongings. Give it a try and let us know how it works!

Wait, on second thought, um, .....give it a second or third thought. Its just pizza. 550 for 10 minutes still makes a nice pie.