The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Using Terracotta (Quarry) tiles as baking stones

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rolls's picture
rolls

Using Terracotta (Quarry) tiles as baking stones

Hi I'm looking into buying these, maybe two, eventhough my oven's small, but I'd love to be able to make two pizza's at a time. I was just wondering what to ask for. Here, we have what most of you know as quarry tiles, but we know as terracotta. Actually there is a huge variety of tiles and stones, just not sure what exactly to look for. Also, once I'v bought it, is there anything I'm supposed to do to prepare it before baking, I've heard that we shouldn't ever wet the stone as its very porous and that we should clean by just brushing. But what about the first time? A main concern of mine is if there are any harmful. The pizza looked gorgeous though, amazing for a domestic oven. Hope you can all shed some light here. Thanks heaps in advance :)

sphealey's picture
sphealey

Given that I worked for a number of years for one of the world's largest manuacturers of industrial and heavy commerical refractory, and I know something of what goes into materials made for non-food purposes, I would strongly recommend sticking with baking stones that carry the NSF mark or materials that have an equivalent FDA approval for cooking surface use.  I admire the frugality and creativity of many TFL members, but I also know what goes into some industrial ceramics and it isn't good stuff for living creatures.


sPh

suave's picture
suave

but you keep saying this time after time, but you never mention just what exactly this something that is in there that everyone should be scared of.

rossnroller's picture
rossnroller

...how about lead?

suave's picture
suave

you do realize that there are many, many ways to glaze ceramics, and not all of them are lead-based? 

rossnroller's picture
rossnroller

Many terracotta products use lead in their manufacture, and the terracotta itself may contain lead. This is my main concern. Besides, you did ask for specifics on what could consitute a health risk in terracotta tiles. Lead is one such substance. I make no further claims one way or the other, except that I am not comfortable taking a risk with baking on terracotta that may contain lead. Hopefully that's made my position clear.

AtlantaTerry's picture
AtlantaTerry

Suave:


Over and over again on this website people say to use UNGLAZED tiles.


Terry

sphealey's picture
sphealey

=== but you keep saying this time after time, but you never mention just what exactly this something that is in there that everyone should be scared of. ===


Might have something to do with those non-disclosure agreements I signed, eh?


By the way, what is your experience with industrial refractory?  Worked in any mixing or firing facilities?


sPh

suave's picture
suave

but I simply don't believe you - basic compositions are well known and are anything but trade secrets, particularly when products have been known literally  for millenia.  And to answer your very pointed question - my chemical engineering degree was in glass manufacturing, and although I moved away from that type of work long time ago I did spend some time in very hot spaces and I still have a good understanding of how it's done.


My feeling is, if you are not willing to substantiate your claims, then you should not be making them.  It would not fly in an industrial lab, would it?

rossnroller's picture
rossnroller

I think it's a bit poor to go accusing another poster of lying - which is what your post above amounts to. Wouldn't it be a little more civil to take a less offensive and aggro line and use some diplomacy in your expression?


Back to the matter of terracotta tiles and lead content, I have no expertise at all but have researched this on the web after hearing somewhere that lead could be present in terracotta, and that this would render such tiles unfit for use in ovens. My research failed to turn up anything definitive, though. I am not prepared to take a risk in using terracotta while I do not have the facts, but would like it cleared up once and for all by someone who really knows. If anyone out there does know for sure, would be great if you could intervene here...?!

suave's picture
suave

There's difference between veracity of a statement and one's willingness to believe in it. 


As far lead contents goes no one will tell you with any degree of certainty what is or isn't in a particular product, but you should realize that ceramics are fired at temperatures that exceed our baking temperatures almost by an order of magnitude, so there're no volatiles to worry about.  Can anything from the surface of a tile diffuse through the parchment and into your loaf.  It's unlikely, but lacking a proof I can't say it won't.  So it all comes down to what you are comfortable with - if you have doubts then don't use it.

rossnroller's picture
rossnroller


Can anything from the surface of a tile diffuse through the parchment and into your loaf.  It's unlikely, but lacking a proof I can't say it won't.  So it all comes down to what you are comfortable with - if you have doubts then don't use it.



- while I have no proof from a reliable source, I won't be using terracotta! My position all along.

sphealey's picture
sphealey

I'm deeply sorry if you "simply don't believe [me]".  It was long ago pointed out that on the Internet, no one knows you are a dog.  Perhaps I am a dog; perhaps I really did work as an industrial engineer and systems manager (including responsibility for the bill of material and costing systems, both of which imply access to the full materials list for the products) for a refractory manufacturer.  Sure, there are some basic alumina products for which the formulas are well-known; there are also many propriatary products for which the formulas are very specifically not known. Which products are covered by non-disclosure agreements as  I mentioned.


I have also worked for a consumer products manufacturing and marketing companies and I know a bit of the wheeling and dealing that goes on behind the scenes as such entities attempt to make a profit and stay in business in the face of the demands from the big-box stores, enough so that I would not cook on a repurposed material for which there is absolutely no material provenence and no intention by the seller that it be used for such a purpose. [1]


And with Target and K-Mart selling NSF-marked baking stones for $18, and one of the regulars here offering an FDA-approved commercial refractory in custom sizes, I don't see much point in taking the chance [I realize that the original poster in this thread is from Australia and the consumer goods situation there may be different].


Again, I deeply and sincerly apologize for offending your beliefs about what is and isn't true; I hope you find it somewhere in your generous heart to forgive me.


sPh


[1] Admittedly the melamine-in-gluten scandal shows that even material specifications and regulatory markings don't mean much if the supply chain is determined to cheat, but at least they are a starting point.

suave's picture
suave

it's all about trust.  For example, that FDA-approved commercial refractory. Is it really approved?  It's not in FDA Inventory of Effective Food Contact Substance, nor does it come up in a search of FDA site.  For that matter, I have a stone I bought from Stan, and it doesn't have any labelling (unlike, say, my NSF-approved stainless steel bowls), so really all I have is Stan's word that it is safe, and I presume all he has is the word of his supplier.

rolls's picture
rolls

Thanks so much, do you know if the same goes for firebricks, or whatever is used for brick ovens?is there anyway the tile place can make it 'safe' on purchase? Thanks heaps for your input :)

mrfrost's picture
mrfrost

Numerous threads on this topic.

rolls's picture
rolls

such as.....lol do you have any links, or should I just do a general search

rossnroller's picture
rossnroller

I have a feeling you have been inspired by the Friday night episode of Masterchef Australia. A couple of observations:


They were VERY irresponsible in not mentioning that some terracotta tiles have lead in them - and having sought out baking tiles, I can tell you it's pretty hard to establish this at the retail source.


Secondly, as someone who has been making pizzas at home for quite a while, I am extremely dubious about their methods. 4 or 5 minutes in a maxed out domestic oven has never, in my experience, been long enough to bake the pizza properly.


I'm about to try their method and recipes, and will be writing a blog on my findings. Will let you know when it's up, if you're interested. In the meantime, good luck - I suspect you'll need it if you follow their directions without modification!


Cheers
Ross

rolls's picture
rolls

Lol you are exactly right! Eventhough, I've been meaning to try this method from ages, seeing it really motivates you to stop procastinating! Please, let me know how you go, I suspect heaps of people will have the same questions after seeing that show. So, can you tell me please what should I be asking for?


Thans heaps

rossnroller's picture
rossnroller

So, can you tell me please what should I be asking for?

Are you still referring to the baking tile? If so, my opinion is that you'd be better off forgetting about that and just buying a pizza stone. They're only $20AUD, and if you keep an eye on the specials at places like Kitchenwarehouse you can get them much cheaper. I bought mine for $7, and it's rarely been out of my oven since!

rolls's picture
rolls

oh okay,. I was just under the impressioin that the terracotta was superior to the pizza stones. Also, I have a brick oven that I need to line with some form of tile as its just a thin metal sheet at the moment and it was burning everything. Someone mentioned firebricks, does this also contain harmful chemicals then? thanks for your advice. By the way, I meant, what do I ask the tile place, as I've heard they can fire it or something, sorry can't remember the exact term right now, to make it more 'safe'. So does this go for all forms of stone, I think I read in Richard Bertinet's book to use granite?

rossnroller's picture
rossnroller

I can't answer your question on what to ask the tile retailer, but I can say that my pizza stone does a perfectly good job of turning out a nice pizza base and producing a good spring in bread.


If terracotta tiles are better, I'd guess it's only because they tend to be thicker, and would therefore retain heat better than pizza stones. For your stated purposes of trying out the Masterchef pizzas, though, a pizza stone would be completely adequate.


I made both pizzas tonight, and as suspected, the pizza base is inferior to those produced by properly proved dough. The toppings were quite nice combinations.


The Masterchef pizzas are quick and convenient, but far from authentic. And their 'classic' margherita is not even close to 'classic', by the way - a true margarita does not have capers or buffalo mozzarella (which goes for around $120 per kilo in Perth). Seeking a terracotta tile is effort wasted on these pizzas IMO. If you've never made pizzas at home, you'll probably like them, but to be honest, you'll find far better pizza doughs on this site - just do a search.


Ditto on my blog. See:


Making Your Own GREAT Pizzas At Home


Or for a sourdough version that is infinitely superior to the Masterchef quickneasy one:


Sourdough Pizzas – As Good As Home Oven Pizzas Get!


Cheers!
Ross


 


 

PMcCool's picture
PMcCool

because of its remarkable heat storage and transfer abilities.  It's about as inert as a mineral can be, so there's no worries about off-gassing or radioactivity as with other materials.  Perhaps you can locate a source in your area.  Here are some links to stove manufacturers, just to give an idea of the possibilities:


http://www.tulikivi.com/www/kotien.nsf/indexen!ReadForm


http://www.hearthstonestoves.com/


http://www.woodstove.com/


http://www.vermontwoodstove.com/


Note that I have no commercial or personal ties to any of these manufacturers, nor have I used any of their products.


Paul

SCruz's picture
SCruz

How about granite floor tile? It's $5 US for an 18-inch square tile and it's 3/8 inch thick. Seems like a perfect size. OR, if I have access to a kiln, can I make a stone from a slap of porcelain clay?

PMcCool's picture
PMcCool

about soapstone.  It is available in tile form, as well as in slabs.  It will stand up to repeated heating and cooling cycles far better than granite.  


If you have a countertop fabricator in your area, you might be able to wheedle some of his scraps.  A cut-out for a sink, for instance, would work very well as an oven shelf, although it might require some trimming to fit your specific oven.  The downside is that, at a typical 3cm thickness, it will take a l-o-n-g time to get that mass up to temperature.  


If I were building a WFO, I'd give soapstone a close look for the hearth floor.  One smooth, seamless piece would make usage and cleaning a breeze.


Paul

rossnroller's picture
rossnroller

The quality of soapstone as a baking surface is something I wasn't aware of until now. Sounds good - although I think you'd want a piece less thick than 3cm for domestic oven use.

PMcCool's picture
PMcCool

But, in tile form, you might find something that is very utilitarian.  It won't be nearly as cheap as some of the other possiblities, sadly.


I see that some vendors offer soapstone baking stones on-line.  However, they persist in making them round for pizza baking and ignore the rest of us bakers.  Plus, they put them in these elegant metal frames and then charge an arm and a leg for them.  There are a few, Vermont Soapstone might be one, that do custom orders.  Not sure how the price would compare to something like Fibrament.


Paul

rolls's picture
rolls

Thanks everyone so much. This thread has been very interesting and informative.


Thanks Ross, will have a look, I've always wanted to try peter reinhart's pizza dough from this site

AtlantaTerry's picture
AtlantaTerry

Rolls:


You mention getting water on the stones. That's only true if the tiles are hot because the water will instantly turn to steam and likely crack them.


In the past I went to a big box home improvement store and bought large unglazed tiles.


There is no "first time use" prep. Just be sure to sprinkle corn meal on top so the bread will slide off easily. Then be sure the tiles are hot HOT before placing the dough on top.


Have fun!


Terry Thomas...
the photographer
(and bread baker since 1975)
Atlanta, Georgia USA
www.TerryThomasPhotos.com


 

rolls's picture
rolls

Thanks for clarifying that up and answering my questions.

rolls's picture
rolls

oh, I just forgot to mention that I have an electric oven with fan, not sure if this makes any difference ?

AtlantaTerry's picture
AtlantaTerry

Rolls:


You mention your oven has a fan. Hmmm... that sounds a lot like a convection oven.


But I doubt that it matters when it comes to baking on an unglazed tile. It's how hot the tile is when you place the dough on it.


The hot tile will crisp the bottom of the loaf or pizza.


BTW, when I first got into using unglazed quarry tiles I simply used average 6x6" or 8x8" tiles (I forgot which size) and lined the bottom rack with them. They remained in that oven for many years until I moved away.


If you have not tried another trick with baking bread, take an old disposable or one-time-use aluminum loaf tin and put water in it when you turn on the oven. (Not after the tile is hot as a splash of water will crack it.) As the loaf bakes the steam will permeate the oven creating a very crisp crust. BTW, the reason I say to use an old aluminum pan is because it will get ruined since any minerals in the water will stick to it when the water turns to steam.


Have fun baking bread and remember, unlike doctors, we can eat our mistakes.


Terry Thomas...
the photographer
(and bread baker since 1975)
Atlanta, Georgia USA
www.TerryThomasPhotos.com
Skype: AtlantaTerry


 


 

rolls's picture
rolls

Thanks for that, I was just referring to the preheat, can I go straight to max temp eventhough, it might heat up faster than a gas stove usually would? thanks.

AtlantaTerry's picture
AtlantaTerry

Rolls,


Relax and experiment with various heating times and temps. (Keep notes.)


Best.


Terry Thomas...
the photographer
(and bread baker since 1975)
Atlanta, Georgia USA
www.TerryThomasPhotos.com
Skype: AtlantaTerry


 

rolls's picture
rolls

Thanks again, will do.

rolls's picture
rolls

Thanks will have a look

rolls's picture
rolls

just had a look. thanks for that, looked really good. I thnk the stone really makes a difference. By the way , i loved how they flavoured their oil before brushing on. I missed that invention test, tried to find it but couldn't.


thank you everyone for all your helpful advice. I experimented just with some ABin5 dough, made four loaves, one with a line of cheese and olives down the centre, the rest plain. Covered with disposable roasting pan, ~ 9 mins, then remove. I found the stone actually made a huge diff. The dough I was working on was really really wet, and yet I got excellent oven spring, very crusty and my scoring looked prettier than usual. I want to try again, but a not so wet dough, and maybe baguettes. took some pics with my phone so not sure how clear will try post soon.


Thanks