The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Baking Stones - Glaze in tiles

mido_mijo's picture
mido_mijo

Baking Stones - Glaze in tiles

I bought some tiles at Lowes, and the employee there showed me some unglazed tiles that he would recommend for baking. But since he didn't have any experience or people asking him, I searched online for some info on the tiles.


 


So far I found out an answer to my question.


 


Do I need to seal the Rialto, Botticino, Positano or Murano series tiles carried at Lowe's?
No. During production process there is glaze incorporated in the mixture to help prevent stains.


http://www.delconcausa.com/lowes/faqs.htm


 


So does this mean it's not safe to bake on since there's glaze incorporated into the tile mixture?


 


Thanks in advance.

rolls's picture
rolls

I bought some unglazed terracotta tiles recently as well as a pizza stone, i also started a thread because i was concerned bout the same thing. will try to post a link, i've used both and got a better result with the tiles, for both normal breads as well as pizza, but not giving up on the pizza stone...

philread's picture
philread

Having been a potter for 22 years and invo;ved in the formulating of clays and glazes, I can offer the following information. Terra cotta means "red earth". It is fired at 1040 where it is porous to around 1100 c where it is called soft stoneware and starts to vitrify (become non-porous). Terra cotta is made from silica and alumina and a tiny amount of fluxes (Potash and Soda) which lower and control its melting temperature temperature as well as a little iron oxide which give the rich red colour. All these chemicals are inert at the temperature of a domestic oven. It DOES NOT have lead.


Lead has traditionally been used in glazing for thousands of years. It is toxic but is usually only released by ontact with acids such as vinegar and fruit juices and to a lesser degree tea and coffee. Most countries nowadays have powerful legislation in regard to lead glazes   and they are not used except in special forms which are rigorously tested for solubility.


So buy a tile that is low fired 1040c and porous and not glazed - usually termed earthenware or terra cotta.. Wetting a porous tile shouldn't cause cracking and will release steam which will enhance your crust. Phil Read New Zealand.

rolls's picture
rolls
Paddyscake's picture
Paddyscake

I understand being on a budget. If you are not sure if you are interested in baking bread,use an inverted cookie sheet/jelly roll pan with parchment paper. If you are hooked after 2 loaves, invest in your future hobby. Buy a stone. For about $50, you'll be all set, not have to worry about toxins and be happy camper with awesome bread!


You'll save a whole lot of time and frustration!


Betty

Chuck's picture
Chuck

You're right, completely natural tiles with neither surface glaze nor any "non-staining" ingredients would have been better. Some stores carry them, but other stores in the same "chain" don't. You want the "low tech" tiles, the ones that tend to be the least expensive. I unfortunately don't know for sure the answer to your specific question; what I do know is I'd be "leery" about any tile that advertised stain resistance.


Tiles can be a way to save money IF the right kind is readily available in small quantities and in stock. But if not, tiles can easily become just as expensive as a pizza stone so there's no point. The blanket recommendation of tiles made sense back when Julia Child did it, but is perilously close to outdated these days.  Looking around for a good price on a pizza stone that fits your oven can be a good way to go.


Your experience with a store clerk actually giving some advice about baking is quite unusual. Most store clerks will simply demur about baking, saying something about "not approved for food use". Just ignore them (don't bother arguing with them). Most clerks not only have been told to avoid saying anything that could result in a liability lawsuit, but also are pretty clueless about baking tiles. If it's kilned at high temperature, not slate, not glazed, doesn't say "stain-resistant", and doesn't have any warning on the package about causing cancer, it should be okay (even though the clerk won't ever say that).

LindyD's picture
LindyD

I went that route about three years ago, spending a lot of time and gas money visiting home improvement stores and tile/stone shops looking for unglazed tiles I could use as a baking stone.


After reading the warnings about the release of carcinogens on the side of a box of unglazed quarry tile, I asked myself if I really wanted to use a product manufactured for flooring and pathways in preparing my food.  A product that could release carcinogens if it was scratched or cracked.  Nope.


It also dawned on me that I had probably spent more in time and gas money searching for tile than the $37 (which includes free shipping) cost of a food safe baking stone at Amazon.


I know some like using floor tiles in their oven because it's cheap.  I just personally prefer the comfort of using a stone manufactured solely for food prep/safety. 


In answer to your question, mido-mijo, you may want to research the health hazards of the chemicals used in the glaze incorporated into your tile to make it stain resistent.  Am guessing you are not going to like what you find.

mido_mijo's picture
mido_mijo

I tried the cheap route and ended up going in circles. haha...


I ended up returning the tiles since they didn't seem safe to bake on. And ended up ordering from amazon.com


I'll try the cheap route when i can source them easier....


 


Thanks everyone for their help!!!

JBeddo's picture
JBeddo

I'm a potter too, and thought about just making myself a pizza stone but instead I bought a nice 5/8 inch think kiln shelf at my local clay supply, which for me in Santa Fe Clay as I live in Northern New Mexico. It's 8 sided so it's shaped like a stop sign and about 15 1/2 inches wide not round but a great size for a home oven. It cost just under $25.

Danai Wangsiri's picture
Danai Wangsiri

I have a piece of artificial mable (white) , a left over of cut-out for sink counter. Is it safe for baking?

PMcCool's picture
PMcCool

If memory serves (hah!), artificial marble is a mixture of resins, marble dust, and coloring agents.  And probably some other stuff I haven't heard about.  The key would be the resins, since those would melt at baking temperatures.  There's even the possibility of the material burning.


Paul

Danai Wangsiri's picture
Danai Wangsiri

Thanks Paul.

Tatoosh's picture
Tatoosh

I have a very problematic gas oven so I am trying to construct a homemade baking stone here in the Philippines.  Baking stones are generally unheard of and not seen in the stores at all.


I found some clay building bricks, unsealed, but rather soft.  They are 1 inch thick, 4 inches wide and 8 inches long.  Six of them cover abut the same area as one of my jelly roll pans.


I am having six of them put in an aluminum frame with handles to make them easier to move in and out of the oven as necessary.  Since no one knows here just exactlly what the composition of the brick is and since it is fairly soft, I expect to use parchment paper on top whenever baking. 


Just curious if anyone knows if there is any reason not use these? I should have the homemade brick baking stone back from the fitter's shop in the next day or two, so I will upload a photo when I have it back.


Tatoosh (in the cool mountains of Luzon)

Chuck's picture
Chuck

Admittedly I don't have either direct experience with bricks such as you describe or with experiencing totally different availability of materials in a different country. Tile availability has become so haphazard here that most now find obtaining a "baking stone" from some cooking supply to be easier/cheaper than obtaining tiles; it sounds like your experience is totally different though.


(Also search here for the idea of baking bread on a metal sheet without using a baking stone at all. Although at first this idea may sound heretical, quite a few people have had good experiences, and the theoretical explanations of how it works sound prima facie reasonable. Of course without some sort of stone to act as a moderator, you'd probably need to get your oven fixed so it more reliably maintains the temperature you choose.)


On to specifics: I'm very suspicious of anything that's "soft". I expect at best they will crumble into dust after only a few uses in a hot oven and make a giant mess. (And at worst they might absorb a lot of water which will turn to steam, causing them to explode!). The kind of tiles I use are so hard they could only be cut with a diamond wheel tile saw. Suitable tiles are often called "terra cotta".


I wouldn't bother with moving them in and out of the oven either (of course it's always possible your oven is so different from mine that moving is a requirement after all:-). I just leave my tiles in the oven all the time. When I'm baking something other than bread, I either just sit it on the stone anyway, or put the other rack above the stone and use that. It works fine. (After all, if you need a temperature moderator in your oven, you need it for everything, not just bread.)


I've two possible suggestions for an alternative:



  1. Find some kind of tile that's meant to be walked on (perhaps hallway, perhaps outdoor patio, etc.), not anything that's meant to go into a wall.

  2. If the additional postage to your location isn't too outrageous, just order from Amazon. "Online shopping" like this is typically a requirement even within the U.S., and certainly shouldn't be "exotic" elsewhere. (I order stuff from Hong Kong all the time, and typically pay just a few dollars postage and wait just two or three weeks. I hope something similar will work from the U.S. to the Philippines.)


 

Tatoosh's picture
Tatoosh

I hear your concerns loud and clear.  I am not too concerned about transferring any of the "brick" material since I plan to either use parchment or aluminum foil when I cook directly on them.  But I am concerned about them exploding due to moisture.  My first steam test will be done with some hesistation.


The frame design is mine and has one obvious defect now that it is in place.  I added handles to make it easy to move.  But they also keep us from placing pans  (like jelly roll pans or baking sheets) on top of it.  I will probably have a second one made if this one works without handles or with them placed horizontally so they don't cause a problem with placing baking sheets on top of it.  I may use this one as a top to form a "brick oven" if this works out.


 


Baking "Bricks" in the oven


 


 


The bricks are not falling apart, but they will crumble if bumped againste each other. We baked a cake with it in and it definitely helped keep the oven temperature much more steady, even with the door opened to check doneness.  And the cake baked more evenly, she didn't bother to rotate the cake so that the front and back cooked evenly.


As long as it doesn't suck up moisture and expode, I will be quite happy with it. As to the oven, I have been around and around with the company I bought it from and their service center.  Getting it fixed here in the Philippines is way more problematic than it is in North America. 



Buying in the USA and shipping here is posslible but somewhat problematic.  I get a box or two shipped every couple of years, and I probably will do a couple of standard baking stones in the future.  But that won't be until next year, so I am looking for something I can use in the meantime.


I look forward to giving the brick baking stone a try with bread now.  My English Muffins, which only spend 10 minutes in the oven, are pretty good, but the french/italian loaves really don't come out all that presentable.  I am actually trying to come up with a good Subway style loaf for sandwiches.  Of course I am baking at 5000 feet which adds to the challenge.  


Tatoosh


 

Pakrat63's picture
Pakrat63

Tatoosh,


i like the looks of your brick rack. i nearer to sea level in LapuLapu City, Cebu.


What kind of range do you have? Did you get it locally? We are looking at a couple of small models made by Germania, available through Imperial Appliance here in Cebu. i am also giving a lot of thought to building a WFO, but real confident about finding fire brick. Lot's of HollowBlocks around though!


When i first got here in early June, my girlfriend was very insistent that i make lasagna for the local fiesta. i found (almost) satisfactory ingredients to make 3 pans worth, and she assured me that she had a friend with an oven i could use. The morning of the fiesta i have 3 unbaked lasagnas ready to go, and here come this microwave looking thing... it turned out to be a microwave/convection combo, but scared the heck out of me. All of my baking has been in a conventional home range or a gas bbq. The lasagna was well recieved, but i could only bake one at a time, and never got enough heat into the middle to get that good melt that lasagna needs...


Are you able to find good hi protein bread flour or WW in Luzon? i haven't looked too hard here yet, but haven't seen any. 


Thanks from "a Pinoy in Training"

Tatoosh's picture
Tatoosh

Hi there! Mactan Island, eh? Nice.  The La Germania seems like the way to go. Mine is an Italian brand that looked great but didn't deliver, quality wise.  I made a fair amount of lasagna here too, though not in the last year or so.  You have some good shopping options in your area. A wood fired hearth sounds wonderful but who's gonna work it in the heat?  Or would you bake at night?  One would work, temperature wise, here in the Cordillera and if I build a house I will consider that, though I am more tempted to add a bakers oven or pizza oven to the kitchen should that time come.


Yes, you should be able to find bread flour and cake flour if you hunt around.  The "local" stuff will be much cheaper than imported US brands like Pilsbury.  Haven't seen any King Arthur flour here but you never know what will turn up on a store's shelf.  Just remember that because you saw it once doesn't mean it will be there next time.  If you buy the local stuff, be sure to run through a mesh filter, not just to seive but to get rid of the bugs too. (I can imagine our Stateside readers shudder, but it is life in SE Asia.)


Ask around for where the bakers buy their flour and you should find at least a couple of stores taht will carry baking supplies and something of a flour selection, but nothing on the order of selection compared to the USA or Europe.  You can try Carbon but be careful and take your girlfriend, if you go shopping there.  Huge market but rough neighborhood. 


Where I live, a much smaller but somewhat cosmopolitan city by Philippine standards, a kilo of flour is usually 37 pesos or 80 - 90 cents.  A small bag of Pilsbury flour will be three to four times that for slightly over half that weight.


There is at least one "Cebu" based forum where you can get shopping advice and pointers toward good gear.  Try searching for living in Cebu on google.


Tatoosh

Pakrat63's picture
Pakrat63

We went to the market at Carbon' with some teachers to get supplies for the fiesta. Great Market, and i am sure the locals got a kick from seeing a 300lb sweaty white guy toting a 20 kilo bag of vegies thru the night...


The second advantage to a WFO for me is that the dang thing will be outside! Even if there is a roof over it (i am considering the combo grill/oven/smoker plans published last spring in MotherEarth News) there should be enough breeze to make working it in the tropical heat less of a torture. (The first advantage is of course pizza!)


Mido and others, please excuse us for hijacking your thread. In the states, after my first cheapo pizza stone shattered, i tried to replace it with Home Depot Terracotta tiles. They didn't like life in my oven, perhaps i should have "Seasoned" them with a long slow bake at about 250f, but they cracked under what started out as good looking french loaves. Then i found another pizza stone at Bed, Bath, and Beyond for about $10. It came with a cheap metal rack and a pine peel, and went from the oven to the gas grill for several months before i moved to Asia.

Chuck's picture
Chuck

Quote:
... after my first cheapo pizza stone shattered, i tried to replace it with Home Depot Terracotta tiles. They didn't like life in my oven, perhaps i should have "Seasoned" them ...

My experience is that (contrary to what you'd expect from a chain:-) not every Home Depot carries the same quarry tiles. My guess is that because such tile is a very heavy to ship yet highly cost-sensitive to sell item, each region develops their own sources and is considerably constrained by what's easily available to them. Different Home Depot stores also carry slightly different merchandise depending on what their particular customers want.


So even the same identical term ("terra cotta") at the same chain ("Home Depot") is not necessarily the same. If what your Home Depot sells as terra cotta isn't the right stuff, it won't work (and may even be dangerous), and there's nothing you can do about it. "Seasoning" isn't necessary with the right stuff, and almost certainly won't fix up the wrong stuff so you can use it anyway.


Combined with purpose-made "baking stones" being much easier to find and much cheaper than they were thirty years ago, such problems probably explain why tile is so often no longer a helpful idea.

Tatoosh's picture
Tatoosh

I am a hesitant to do the boiling water in hot pan for making french bread with my new brick baking stone, at least in the kitchen. Chuck's comments have made me cautious.  I am thinking I wil give a wet brick (I have a few extra) a test on my barbecue grill.  A can of hot water and a brick over some hot coals should give me an idea if the brick will turn into an unintentional Improvised Explosive Device (IED) after I cover it and let it absorb the moisture.


Teketeks, whose baguettes I am in awe of, uses foil-covered bricks to help even out her oven temperaturel.  Perhaps that would be a good idea for me.  It would minimize the chance of a spill causing a problem at the very least. 


I may BBQ pork skeweres today, which will give me an excuse to test a wet brick and a boiling water scenario too.  Better to explode it in the Weber than the kitchen oven.


Teketeke's thread on french baguettes and foil wrapped bricks: how-i-finally-have-open-crumb-and-ear-without-pouring-water-or-using-high-heat-500f


Tatoosh

Pakrat63's picture
Pakrat63

As pointed out else where, the good thing about terra cotta tiles from The Big Orange Box is the price- i was didn't make a special trip to get the tiles, and at about $.99 each, when they failed it was irritating, but not tragic.

Tatoosh's picture
Tatoosh

Gave the bricks I use in my homemade brick baking stone a fairly unscientific moisture test.  We decided to do some pork bbq, so we got the grill nice and hot. I put one brick and a can to hold water on the grill and let them heat up for a few minutes.  Then we added boiling water and put the kettle lid on the grill. 


Happily, no problems.  So we removed the can and tried pouring water directly on the brick.  It sizzled, soaked some up, and laid there.  No explosion and no cracking.  I realize that a longer heating period would be a better test, but the troops were hungry and willing to forego supper for only so long.


Based on my  off-the-cuff tests, I am more comfortiable with leaving the unit in my oven and will probably have a second made without handles so I can park baking sheets on it. Cost of bricks are 9.5 pesos each and the frame is 400 pesos custom made.  So all told I am out about $10 US per unit. 


We plan to try homemade pizza on it tomorrow. I made a poolish for my pizza dough and will let it sit overnight, then make pizza dough in the afternoon.  I will put the pizza on parchment paper and set on the bricks after I get the oven up over 400 degrees which is all my thermometer can read. But I am hoping the bricks will let me have a better, crisper crust on my pie.


Tatoosh

missmoosy's picture
missmoosy

Hi, I have a motorhome and my oven does not give out even heat.  And I have heard that by putting four 6" unglazed tile will keep the oven at an even temperature.  Does anyone have any suggestions and where can I buy these tiles?

Chuck's picture
Chuck

You may do even better with "firebrick", something that looks like a regular brick (except probably light tan rather than red), and is made out of a slightly different material that stands up to heat better. They're typically used in fireplaces. If your oven is small, you may wish to get the thinner half-brick "splits" - they'll work well to spread the heat. If you have enough room, the full-sized bricks will hold more heat (the common term is "thermal mass") and do a better job of stabilizing the temperature in your oven. They should be available at a building supply store (perhaps one of those "super lumberyards" that sell not just lumber but paint, bricks, etc.). Or try looking up "bricks" in your Yellow Pages.

If you prefer to go with the unglazed tiles, they're likely available at your local big-box hardware store (Home Depot, Lowes, etc.). But what's very easily available in some areas is hard to find in other areas (these tiles are one item that's not standard across all the stores in the chain). If you try a couple of nearby big-box hardware stores and they don't have them (or insist you buy a whole pallet rather than individual tiles), you have to decide whether the expense and delay of a special order is worth it or whether it's more prudent to just give up and get something else. The days when these tiles were universally easily available are gone. Big stores that sell lots of variations of flooring (hardwood, tile, linoleum, indoor, outdoor, etc.) may also be able to supply them - almost certainly as a special-order ( they may call them "Saltillo").

Either way, you want very plain simple things. If the box or the shelf says anything about "stain resistant" or "sealed" or "impregnated", just leave without buying anything. Such things are a modern wonder great for floors   ...but not great in your oven with stuff you eat. Likewise avoid glazed tiles. Although arguments rage over just how much (if any:-) hazard these things pose to food, it's better to be safe than sorry (especially since if there's a risk it will be for very low level but chronic health problems that are virtually impossible to diagnose and may lead your physician to think you're crazy).

Do be aware that the cost of stabilizing the heat in your oven is these things will almost certainly make a doddering fool out of your oven's "preheat ready" indicator. The indicator will sound far sooner than when your oven is really preheated. There are various rules of thumb, all the way from "double the time the preheat ready indicator says" to "one hour preheat no matter what".