Newbie Brick Research Question

[Yellowbeard]

Hi. I've been thinking about building a wood fired oven for pizza and bread for years. A friend built a cobb oven several years ago and loved it. He moved and is currently building a new one.

I am getting ready to build a house and was thinking about building a brick oven. Then a buddy who makes pottery came up with an interesting find - a bunch of bricks that used to be a part of a brickmaking kiln around 100 years ago (see pictures). The best part? They were 60 cents apiece.

I have a big truck so I made some trips hauling bricks for him on the condition that I could buy some of them myself for my pizza oven.

When I got there, I found out that the guy selling them also had a bunch of clinkers from the kiln. Clinkers, in case anyone doesn't know, are bricks that didn't fire quite right. They're awesome.

So my romantic plan became: Build an oven using the parent bricks (those that made up the kiln) and use the children (the clinkers) for the face bricks.

Now the problem:

I started doing some research on oven design and then started stumbling onto information that seemed to indicate I should NOT use high duty or super duty bricks for a wood fired oven. But looking deeper, I ended up not being certain about that.

One thing I am pretty sure of is that I should use something else for the floor. But is it OK to use these bricks for the dome? Since I have a LOT of them available, I am hoping to build a large dome (maybe 42-50 inches). I have hopes of being able to bake bread in this oven as well, as I have been getting into sourdoughs.

One thing I read seemed to indicate that the high duty bricks don't insulate well. I am wondering if I can solve that by just over-insulating the outside. Or could I just use MORE bricks to build a bigger thermal bank?

Any advice on any of this would be greatly appreciated. I hope I don't find out I can't end up using these.

Also, any information on what I should buy for the floor (and I prefer large spans to make minimal seams) would be greatly appreciated. Since I saved a lot of money on the bricks, I am willing to spend a bit on the floor if that can potentially solve the problem.

I'd also take advice on design.

[Yellowbeard]

Been doing more looking around. It sure LOOKS like these will be OK. However, I am still unsure what to use for the floor. Anyone have good advice on that?

Thanks!

[MarkJerling]

Have a read of this: https://www.fornobravo.com/pompeii-o...and%20roasting.

[Yellowbeard]

Have a read of this: https://www.fornobravo.com/pompeii-o...and%20roasting.

This is actually one of the things I read that gave me pause. However, I saw other information that seemed to indicate that other users were using this type of brick successfully.

Thanks for the info!

[SableSprings]

Welcome to the forum Yellowbeard! I certainly am not "the expert" in firebricks, but from what I remember from other posts over the years is that using the high duty bricks for the dome is not a problem. One of the main issues is that they are more difficult to cut and those that have used them for the dome find that they will wear out a blade or two doing the cutting. For your cooking floor, over the years we have always recommended purchasing new medium duty firebricks. Many people have used splits because they heat up a bit faster (since they are half the thickness of a "normal" firebrick). If you are going to bake bread and plan to bake other things in your besides pizza, I'd recommend using full size firebricks. They may take a little longer to heat up to pizza temps, but not that much more. Once fully charged with heat, they really allow you a lot of cooking options the day(s) after pizza. I have a 39" oven and will bake between 20-30 loaves (large baguette size) to give to my neighbors each week. I usually load the oven with wood and do a damped down burn overnight to fully saturate the bricks before baking around 2-3 in the afternoon. It takes my oven (with full bricks on the cooking floor) about 2 hrs to give me reliable pizza temps and I keep a good fire with coals going on the side.

The article that Mark earmarked for you (in my opinion) is really focusing on the bricks to be used for the cooking floor. I'm hoping we'll get some other comments here from folks that have used the high duty bricks in their domes. I'm not sure what the issue might be with insulation of the dome if you used HD bricks...ceramic batting is pretty good stuff and although the HD bricks could easily withstand higher temps, I don't think that will be an issue as you learn the best method and times for firing your oven.

Hope that helps and kudos on scoring those fantastic bricks! Definitely will want to save some of those stamped bricks for your outer enclosure as an art/historic addition to your entertainment/party area around the oven.

Good luck and I'm looking forward to watching your build thread when you start posting.

[Yellowbeard]

Welcome to the forum Yellowbeard! I certainly am not "the expert" in firebricks, but from what I remember from other posts over the years is that using the high duty bricks for the dome is not a problem. One of the main issues is that they are more difficult to cut and those that have used them for the dome find that they will wear out a blade or two doing the cutting. For your cooking floor, over the years we have always recommended purchasing new medium duty firebricks. Many people have used splits because they heat up a bit faster (since they are half the thickness of a "normal" firebrick). If you are going to bake bread and plan to bake other things in your besides pizza, I'd recommend using full size firebricks. They may take a little longer to heat up to pizza temps, but not that much more. Once fully charged with heat, they really allow you a lot of cooking options the day(s) after pizza. I have a 39" oven and will bake between 20-30 loaves (large baguette size) to give to my neighbors each week. I usually load the oven with wood and do a damped down burn overnight to fully saturate the bricks before baking around 2-3 in the afternoon. It takes my oven (with full bricks on the cooking floor) about 2 hrs to give me reliable pizza temps and I keep a good fire with coals going on the side.

The article that Mark earmarked for you (in my opinion) is really focusing on the bricks to be used for the cooking floor. I'm hoping we'll get some other comments here from folks that have used the high duty bricks in their domes. I'm not sure what the issue might be with insulation of the dome if you used HD bricks...ceramic batting is pretty good stuff and although the HD bricks could easily withstand higher temps, I don't think that will be an issue as you learn the best method and times for firing your oven.

Hope that helps and kudos on scoring those fantastic bricks! Definitely will want to save some of those stamped bricks for your outer enclosure as an art/historic addition to your entertainment/party area around the oven.

Good luck and I'm looking forward to watching your build thread when you start posting.

This is excellent to hear and jives with what I was thinking. Thank you for explaining.

So when it comes to the floor, is the only reason to get "special" floor bricks in order to minimize floor seams? I'm sure I can easily get new medium duty brick for the floor and I have also come to the conclusion that I need thicker bricks in the floor for more heat capacity if I want to also do bread. One other question about bread: Do you do anything special for steam or just use a wetter dough? I have seen different options.

I will DEFINITELY be featuring some of those awesome maker's marks in my build in a number of ways - thinking about how that will look now, actually.

Hopefully we will get to start building a house soon, but I am married to an architect so there will be some planning in there. I also have to sell the current house first. Regardless, I am hoping to get a lot of the underpinnings (slab, cinderblock, what have you) done during house construction so all I have to concentrate on afterward is the dome and facing itself. It won't be next week, but hopefully I can start documenting by next year(ish).

Thanks!

[Yellowbeard]

Have a read of this: https://www.fornobravo.com/pompeii-o...and%20roasting.

By the way, I LOVE your country. My wife and I honeymooned there in 2005 and it is absolutely the most beautiful place I have ever been. It started us drinking wine (pinot, natch) and we've wanted to return ever since. Just thought I would let you know.

[MarkJerling]

By the way, I LOVE your country. My wife and I honeymooned there in 2005 and it is absolutely the most beautiful place I have ever been. It started us drinking wine (pinot, natch) and we've wanted to return ever since. Just thought I would let you know.

Thank you. I'm an immigrant here. We came here 20 years ago from South Africa. It's a lovely little country.

[SableSprings]

This is excellent to hear and jives with what I was thinking. Thank you for explaining.

So when it comes to the floor, is the only reason to get "special" floor bricks in order to minimize floor seams? I'm sure I can easily get new medium duty brick for the floor and I have also come to the conclusion that I need thicker bricks in the floor for more heat capacity if I want to also do bread. One other question about bread: Do you do anything special for steam or just use a wetter dough? I have seen different options.

Thanks!

We recommend the new firebricks for the floor because they are "clean" of chemicals or weird compounds. For example firebricks used in pottery kilns may have residues from the various glazes used that contain heavy metals or other "bad" stuff. I have never heard anyone complain about seams in their pizza crust. Making sure your floor is level is important so you don't catch the edge of the peel when loading a pizza or bread dough. That said, I've got a couple of edges in my cooking floor brick joints but after +10 years of baking bread I don't even think about them anymore. One of the problems with using larger sections for your floor is that larger pieces of refractory materials are more likely to crack...bigger top surface, more difficult to heat evenly.

I use a pump up sprayer that delivers a pretty good amount of mist into the heated oven chamber...much better than those multiple squeeze misters. Also, when you put more than two or three loaves in the oven to bake, they actually give off quite a bit of moisture as well. The higher % hydration doughs can certainly take higher temps. My Baguette dough is a little over 66% hydration and I have a soft bread made with durum & high gluten wheat flour that runs about 70%. Both breads can be baked anywhere from 550-575F (my preferred temps) in about 15 minutes. I do my whole wheat a lower temp and lower hydration (60%) because I didn't like the way it would spread out before rising...I wanted a little more compact loaf. Obviously there will be a lot of fun experiments in your future and I'm looking forward to helping in anyway I can.

I've attached a couple pictures of my sprayer mister which holds about 3.5 pints of water. Hope this helps...

[Yellowbeard]

We recommend the new firebricks for the floor because they are "clean" of chemicals or weird compounds. For example firebricks used in pottery kilns may have residues from the various glazes used that contain heavy metals or other "bad" stuff. I have never heard anyone complain about seams in their pizza crust. Making sure your floor is level is important so you don't catch the edge of the peel when loading a pizza or bread dough. That said, I've got a couple of edges in my cooking floor brick joints but after +10 years of baking bread I don't even think about them anymore. One of the problems with using larger sections for your floor is that larger pieces of refractory materials are more likely to crack...bigger top surface, more difficult to heat evenly.

I use a pump up sprayer that delivers a pretty good amount of mist into the heated oven chamber...much better than those multiple squeeze misters. Also, when you put more than two or three loaves in the oven to bake, they actually give off quite a bit of moisture as well. The higher % hydration doughs can certainly take higher temps. My Baguette dough is a little over 66% hydration and I have a soft bread made with durum & high gluten wheat flour that runs about 70%. Both breads can be baked anywhere from 550-575F (my preferred temps) in about 15 minutes. I do my whole wheat a lower temp and lower hydration (60%) because I didn't like the way it would spread out before rising...I wanted a little more compact loaf. Obviously there will be a lot of fun experiments in your future and I'm looking forward to helping in anyway I can.

I've attached a couple pictures of my sprayer mister which holds about 3.5 pints of water. Hope this helps...

Catching an edge was more what I was worried about. I don't anticipate a lot of trouble with lines in the pie or bread crust. Just want to make sure things are smooth for the peel.

I was thinking the same thing about new bricks. My understanding of the history of my bricks is that they were in a (clay) brick kiln - no glazes - that was wood fired. So I am not over worried about chemicals. But still, to be on the safest side, and because my bricks are worn a bit after 100 years, I would rather use clean new bricks. Plus, research had indicated that I would burn my crusts.

Now I WAS thinking that I might be able to put down a layer of my super duty bricks and then a layer of medium duty splits on top of those. Anyone have any thoughts on that?

Your steam system seems FAR more sophisticated than my plan, which was to put a pan of water in there - maybe filled with scoria for wicking. So I am guessing you load your loaves and then just spray some mist in and close the door kinda thing?

I have too many hobbies. Just got back on the sourdough horse and FINALLY feel like I got closer to the kind of loft I want (I was abusing my colony, it turns out, and after REALLY making sure I fed it twice a day for a while my results were way better). That's PART of what made me start leaning in to thinking about getting a pizza oven built again. Now I just need to sell my old Country Living Grain mill and buy a Diamant.

Thanks for the info!

[SableSprings]

As to catching the peel edge, I move my dough loaves (or loaded pizza skins) to the spot I want to place them and use a minor slide forward and then pull the peel out from under. You don't really catch an edge that way. I've seen a lot of folks start the slide as they enter the oven, speeding up towards the middle and then jerk back. That long forward slide is the problem...just no reason for it (unless your pizza is so loaded you can't hold it off the cooking floor...).

I really would not recommend doing the double brick layer on your cooking floor. If you want to increase the stored heat, you'd be better off setting the bricks on their short side...effectively doubling your floor thickness. The issue however comes back to heat transfer speed within the brick. Cool down the surface layer (with a bread load for instance) and it takes a while for the heat in the lower portion of the brick to equalize with the cooler top. My experience with fully saturated medium duty bricks (equalized to 575F) is that I can bake two loads of my 400 g baguettes (that's about 8-10 loaves per load) without pausing more than the time it takes to bring out my second proofing sheet from my prep room. So with a thicker floor, once equalized, you'd probably get a similar situation, the difference being that after a couple bread loads, you'd wait a half hour and your oven floor would rise back up to probably 560F or so (just a guess depending on lots of factors). So if you're doing a small commercial bakery, a thicker floor would be an advantage...but it would take longer (and more wood) to bring back to cooking temps with a pre-bake firing. I have done over 30 loaves (three different types of bread) from one firing and I only stopped because I ran out of dough and neighbors on the road to give it to... Yes, my temps were down at the end of the +30 loaf bake but I was at the perfect temp for some Challah and other soft enriched bread types.

The problem I had with the pan/water method was getting a more even distribution of steam throughout the oven. I spray the interior of the oven, load half the loaves, spray again, finish the load and then give it one final spray. I spray into the center of the oven and slightly up toward the dome which gives me a nice rich steam cloud for the critical oven spring stage. I do use my light cooking door to keep the spray & heat in the oven in between each of those steps...

I feed Chef Bill (my 36 year old "regular" starter) about twice a week and the same for Adelle, my whole wheat starter. My timing is what I feel is important since I keep my prep room cool when not getting ready to build my preferments. I make sure both Bill & Adelle are fed no later than Wednesday because I start my doughs Thursday afternoon/night for a Friday afternoon bake. At 60F in the prep room, both starters are bubbling away when I start putting my pre-ferments together.

I have considered getting a grain mill but have been unable to justify the time & money when I can buy 50 pounds of good quality flours for $25-$30 a sack. I've been using Shepherd's Grain because they print the regional family farmer's name & info on each sack...and I'm very pleased with the consistent quality of the flours I've used from them.

Sorry to have been so long winded here...I hope you didn't nod off and hit your head on the keyboard...

Hope that info helps somewhat in your planning.

[Yellowbeard]

As to catching the peel edge, I move my dough loaves (or loaded pizza skins) to the spot I want to place them and use a minor slide forward and then pull the peel out from under. You don't really catch an edge that way. I've seen a lot of folks start the slide as they enter the oven, speeding up towards the middle and then jerk back. That long forward slide is the problem...just no reason for it (unless your pizza is so loaded you can't hold it off the cooking floor...).

I really would not recommend doing the double brick layer on your cooking floor. If you want to increase the stored heat, you'd be better off setting the bricks on their short side...effectively doubling your floor thickness. The issue however comes back to heat transfer speed within the brick. Cool down the surface layer (with a bread load for instance) and it takes a while for the heat in the lower portion of the brick to equalize with the cooler top. My experience with fully saturated medium duty bricks (equalized to 575F) is that I can bake two loads of my 400 g baguettes (that's about 8-10 loaves per load) without pausing more than the time it takes to bring out my second proofing sheet from my prep room. So with a thicker floor, once equalized, you'd probably get a similar situation, the difference being that after a couple bread loads, you'd wait a half hour and your oven floor would rise back up to probably 560F or so (just a guess depending on lots of factors). So if you're doing a small commercial bakery, a thicker floor would be an advantage...but it would take longer (and more wood) to bring back to cooking temps with a pre-bake firing. I have done over 30 loaves (three different types of bread) from one firing and I only stopped because I ran out of dough and neighbors on the road to give it to... Yes, my temps were down at the end of the +30 loaf bake but I was at the perfect temp for some Challah and other soft enriched bread types.

The problem I had with the pan/water method was getting a more even distribution of steam throughout the oven. I spray the interior of the oven, load half the loaves, spray again, finish the load and then give it one final spray. I spray into the center of the oven and slightly up toward the dome which gives me a nice rich steam cloud for the critical oven spring stage. I do use my light cooking door to keep the spray & heat in the oven in between each of those steps...

I feed Chef Bill (my 36 year old "regular" starter) about twice a week and the same for Adelle, my whole wheat starter. My timing is what I feel is important since I keep my prep room cool when not getting ready to build my preferments. I make sure both Bill & Adelle are fed no later than Wednesday because I start my doughs Thursday afternoon/night for a Friday afternoon bake. At 60F in the prep room, both starters are bubbling away when I start putting my pre-ferments together.

I have considered getting a grain mill but have been unable to justify the time & money when I can buy 50 pounds of good quality flours for $25-$30 a sack. I've been using Shepherd's Grain because they print the regional family farmer's name & info on each sack...and I'm very pleased with the consistent quality of the flours I've used from them.

Sorry to have been so long winded here...I hope you didn't nod off and hit your head on the keyboard...

Hope that info helps somewhat in your planning.

Your info is helping a GREAT DEAL with my planning - thanks!

I will not plan a double brick layer. I will probably do one layer (full thickness) in a herringbone pattern.

I will definitely ask questions when I am doing my build and when I start making bread. VERY stoked to have your input.

I am super thankful for your comments re: starters. Mine is not quite that old. But I did make it from scratch using several beers and other methods of capture. I definitely made my best loaves ever when I got back on the horse recently. However, it sounds like I don't necessarily need to feed quite as often as I am. Any advice you have in that area is welcome.

Thanks for all your help!

W.C.