Soapstone vs Firebrick ??

[luca]

I live in Vermont and have access to cheap soapstone, granite, firebrick etc. In my second pizza oven, I decided to put a 5/4 inch soapstone floor in, but surrounded it with a rim of 5/4" firebrick (all on a 2" sand base which was sitting on top of a 2" fireproof insulation block from FB). After one or two initial fires, I quickly learned that: 1) soapstone absorbs heat to such a significant degree that the soapstone cooking surface exceeded 1000 degrees easily, burning the bottom of pizzas, and 2) making fires directly on the soapstone led to the development of multiple cracks in the soapstone (due presumably to uneven heating during the burn). Due to both issues, I removed the 5/4" soapstone slab, and replaced the cooking surface with regular firebricks, which are much more suitable to cooking pizza.

As for using the soapstone for the actual oven walls, while it will certainly absorb and hold heat, I would be concerned about both issues cited above: 1) controlling the amount of heat in the walls, and thus perhaps too much air temp, and/or 2) the likelihood of cracking and breakage in the actual walls, creating both a structural problem long term and a likely fire hazard over time. Also, as someone mentioned above, the thermal mass of the oven is at least as important as the material used to build it. Only one inch of wall--even soapstone--will not provide the mass necessary to keep a consistently high air temp without continual heating or relatively large fires. (My oven has 2" firebrick walls covered with 2" of cement cladding topped by a 1" ceramic blanket, all buried in a vermiculite shell about 4" thick on average (and will remain at 500 degrees for two days after the fire has gone out).

Overall, I have found that firebrick is the perfect material for all aspects of a pizza oven in that they are durable (I have yet to replace a broken or cracked one), maintain temerpature well, and can be readily regulated to maintain the 600-700 degree floor temperature which is ideal for a range of pizza/dough types.

[Toomulla]

I am thinking about making a large pizza oven for a commercial application out of soapstone. The dome and floor will be 1 " thick soapstone with a ton of insulation. Any thoughts on the topic?

sounds like iT will not have sufficient thermal mass to sustain long term cooking without a constant heat source, I also doubt the structural rigidity for a mobile oven which are most often cast

[Brendon]

I am thinking about making a large pizza oven for a commercial application out of soapstone. The dome and floor will be 1 " thick soapstone with a ton of insulation. Any thoughts on the topic?

[windage]

Re: Soapstone vs Firebrick ??

My take on the porousity and crust is a bit different than David's. Right or wrong in logic, my feeling is that the stone and the crust create a layer of active steam that escapes out under the pizza, out the top and into the nice little bubbles in the crust, and in the end you get a crispy crust.

I used a 3cm soapstone pizza stone in my oven for a couple of years, mostly to bake bread on but also for the ones and twos pizzas from time to time. What I found is limited to the ability of my kitchen oven to reach more than 550F, but crispy crust wasn't really a problem.

What I found to be the culprit for soggy crust was over topping with wet sauce and cheese.. I feel that the advantage of the soapstone is getting the temps even on the floor and really being able to slam the heat into the pizza dough. The soapstone can hold more heat per weight and transfer more heat faster than the brick but brick is cheaper and twice the thickness 6cm vs 3cm.

I feel that in an oven where the volume of pizzas is high, the soapstone can heat charge faster than the brick and recover faster to the ideal pizza temps. In most of our ovens volume of pizzas out of the ovens isn't really the problem. The value for our ovens would be getting the heat into storage faster and getting an even floor temp. We might also expect to see a faster evening out of temperatures within the oven so, for instance, when you prep the oven for bread the amount of time to reach an environment where the dome and floor are close to the same temp is decreased. We might also see that, since the floor is non porous, the bread is steamed more fully because this is one less surface absorbinbg the steam.

I've read that brick is better than soapstone for true bread baking, I'm ok with this if it's so. The statments about bread on soapstone are that the bottom cooks too fast relative to the top crust. I don't know and haven't seen any first hand information on bread on soapstone except what I've done and I'm quite happy with the results.

I'm sure that the quality of the pizza and bread is more a function of the cooks knowledge and the ingredients.

Just my opinion..

Chris

Chris, you got it right, the SS moves heat faster, so, no cold spots...we can put pies over one spot all night if we want (but at 81 inches, we don't have to if we don't want)...crispy crust

[GIANLUCA]

Re: Soapstone vs Firebrick ??

Not me! It would be called a "soap oven" probably would melt stick with brick ask the pigs!

[HoneyWood]

Re: Soapstone vs Firebrick ??

Has Anyone ever used soapstone for the dome of the oven?

[GIANLUCA]

Re: Soapstone vs Firebrick ??

Firebrick all the way! It's cheaper and it works

[luca]

Re: Soapstone vs Firebrick ??

P.S. I had a 14"x18" piece of soapstone left over from my oven build, so I placed it in our electric home oven and tried making a pizza on it. Amazingly, after heating the oven for about 45 minutes, it gave a nice browning to the bottom of the pizza!! I tried it again and this time used the broiler for the last 5 minutes or so to get the top browner (which worked great). The bottom line is you can get a very good pizza in a 500 degree home oven by use of a soapstone slab and broiler finish!!

[luca]

Re: Soapstone vs Firebrick ??

I really don't think you will have a problem. I used standard metal and wood utensils on my soapstone for 2 years with no visible problems. The wire brush I used is uniform in bristle length, so there was no chance for gouging. The aluminum turning peel is used with minimal force on the horizontal plane, so again little opportunity for damage. As you will note in my earlier notes, the issue that made me remove the soapstone was not undue or uneven wear; it was the overheating and cracking elements related to intense fires built on the soapstone itself. I've seen soapstone slabs used in commercial ovens (e.g. see American Flatbread ovens) and haven't heard of any problems. Incidentally, they have two slabs with the fire burning between the slabs so that there is no direct fire touching the stone. That assures a slow heating process and allows the soapstone to achieve high heat without cracking.

[nsascher]

Re: Soapstone vs Firebrick ??

I just spent $1500.00 for soapstone to put into an exisiting wood fired oven. I had no idea how soft it was.My fingernail scratches it. I have a restaurant so we use metal paddles and wire brushes. Obviuosly this is going to scratch it terribly. What is everyone using as utensils ?
Nathalie

[mrchipster]

Re: Soapstone vs Firebrick ??

Luca,

Thanks for the update, I was thinking of getting a small 16x16 inch piece of soapstone to experiment on but here, even as a drop from a kitchen remodel they want a lot of money. I will keep on looking for a cheap or free piece I think it would be interesting to try it but I am glad I did not go for the floor insert like you did. It is good to see that people are experimenting.

[luca]

Re: Soapstone vs Firebrick ??

Update on my Soapstone Floor! I wrote previously about my soapstone floor in my barrel vault here in Vermont (see 10/12/12 for the issues). Well last week I decided to remove the soapstone entirely, and replaced it with 1 inch firebricks (the soapstone was also 1" thick). The major problem is that the stuff just got too damned hot, and if I didn't have my laser thermometer at hand, I was almost always burning the bottoms of my pizza. Also, even though I moved the fire off the soapstone after starting it, it still cracked into several pieces, which, fortunately for me, made it MUCH easier to pull the floor out! (The entire slab weighed about 40 lbs. and would have been very hard to handle through the oven door opening of 9x17"). I didn't see any evidence of "shards" as someone else mentioned in another comment, so I don't think it would have been unsafe to continue cooking on it, and the cracks--while completely through the material--did not cause any large gaps etc. because the piece was bordered by firebricks, keeping everything from moving. The lesson here is that soapstone is certainly unnecessary, has unique cooking issues, and must be SLOWLY brought to temperature to avoid cracking. On the other hand, the firebricks work just great, and even they will burn the bottoms if I'm not careful, so nothing was lost in this experiment!

[devilsbrew]

Re: Soapstone vs Firebrick ??

Great thread. Very informative.

[lwood]

Re: Soapstone vs Firebrick ??

Sounds like a bad experience with soapstone.

[Tscarborough]

Re: Soapstone vs Firebrick ??

If nothing else, soapstone is a natural product and as such is highly variable in it's specific properties. Nice landing and counter material, but not so much for the floor of the oven itself.