Baking / Pizza stones

[scott123]

What is it about soapstone that makes it uniquely suitable for baking? Did you try marble at some point, and if so, what was the problem? I was kind of hoping Johnny would experiment and let us know how it worked.

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From the Vermont Woodstove Planning Guide (bold mine):

Soapstone (steatite) is a magnesium silicate that was formed under great pressure and intense heat millions of years ago. There is nothing quite like soapstone. It possesses extraordinary heat retention and transfer properties. Unlike other natural stones such as granite and marble which can also store and radiate heat, soapstone has such an unusually stable composition that it can withstand direct flames indefinitely and be subjected to great fluctuation in temperature with little expansion or contraction.

That fact that it undergoes very little expansion/contraction is why it is so suitable for baking. Granite and marble don't have the same stability when it comes to resistance to thermal shock.

[Patrick S]

Sure, but thermal expansion is only going to be a concern if it is sufficient to actually break the stone. So even if soapstone is superior in this regard, will marble or granite break due to thermal expansion when subject to the temperature changes of a typical oven? If not, you could use these materials in the place of soapstone. I don't know one way or the other, which is why Im interested to see what happens.

JohnnyD, why don't you do a test run using a cheap frozen pizza or something, and see what happens? Maybe put a baking sheet below it in case it cracks.

[IML]

With a decent pizza dough, you don't need a pizza stone half the time. Just heat and humidity.

[SethG]

Count me as a satisfied customer of quarry tiles. If you go to Home Depot, ask for the unglazed ceramic tiles-- they come in gray and red. They're half an inch thick, 6 x 6 inches square, and they cost about 60 cents each. Buy a dozen and you can configure them however you like on your oven rack. I usually put six of them in a single layer, producing a nice 12 x 18 rectangle. They are heavy and sit still on my oven racks. The bottoms are grooved so they don't really slide around.

If you want a thicker thermal mass you can always double them up as well. I like the flexibility of the tiles and I'm very pleased with the results I get. (I might be even more pleased with a Hearth Kit, but I don't think I'm doing any worse than I'd do with your average pizza stone.)

I haven't experienced any of the theoretical problems speculated upon above, such as chipping, flaking, etc. Zillions of bakers use these tiles, so I'm a bit skeptical as to whether there's any problem in using them.

(And, incidentally, I have to disagree with IML. Pizza dough, decent or otherwise, does best with a stone.)

Edited April 3, 2005 by SethG (log)

[scott123]

Sure, but thermal expansion is only going to be a concern if it is sufficient to actually break the stone. So even if soapstone is superior in this regard, will marble or granite break due to thermal expansion when subject to the temperature changes of a typical oven? If not, you could use these materials in the place of soapstone. I don't know one way or the other, which is why Im interested to see what happens.

JohnnyD, why don't you do a test run using a cheap frozen pizza or something, and see what happens? Maybe put a baking sheet below it in case it cracks.

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Do a search for marble or granite baking stones. Try it. They don't exist. Wouldn't you think that if these materials could handle the thermal shock of baking, someone, somewhere, would sell them as baking stones?

I'm all for DIY solutions. If there's a cheaper homebrewed approach that works, I'm the first one to stand behind it. It has to work, though. This is just a square peg in a round hole. Granite and marble can't withstand the thermal shock of baking.

JohnnyD, if you're going to put a frozen pizza on a thoroughly pre-heated piece of marble, please, wear eye protection.

[Patrick S]

JohnnyD, if you're going to put a frozen pizza on a thoroughly pre-heated piece of marble, please, wear eye protection.

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I have cooked food, though not pizza, on thoroughly pre-heated limestone slabs many times when camping (cooking food on top of hot limestone that had been heated by flames), and I cant recall ever seeing any of the slabs cracking, much less exploding in such a manner that would have warranted eye protection. Since I can get them for next to nothing, I think I'll buy a slab of marble and try it myself. If it cracks, then I've lost a few bucks. If not, I've found a cheap pizza stone.

[Patrick S]

Question for more experienced pizza bakers: can you put the pizza on a very thin metal sheet and set the pizza+sheet on the stone, versus sliding the pizza off of the sheet or peel directly onto the stone? For me the first wat seems much easier -- I don't have to worry about pushing the pizza off the (small) stone, and I only have to keep the oven door open for a couple of seconds. Also, what are some guidelines as far as preheating the stones? For instance, for a 1/2" stone, how long after preheat should you wait before baking?

Edited April 4, 2005 by Patrick S (log)

[SethG]

Question for more experienced pizza bakers: can you put the pizza on a very thin metal sheet and set the pizza+sheet on the stone, versus sliding the pizza off of the sheet or peel directly onto the stone? For me the first wat seems much easier -- I don't have to worry about pushing the pizza off the (small) stone, and I only have to keep the oven door open for a couple of seconds. Also, what are some guidelines as far as preheating the stones? For instance, for a 1/2" stone, how long after preheat should you wait before baking?

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Patrick, if you really don't want to slide the pizza, you might try putting your pizza on a sheet of parchment paper on back of a half-sheet pan, and then sliding the paper (with pizza on top) onto the stone. I'd worry that the time spent heating the metal between your stone and your pizza would be detrimental (if only slightly) to your end product.

Sliding pizzas off a peel can be scary, but it is also thrilling! And not so hard once you get the hang of it.

Edit: and heat the stone for a long time. Preheat for an hour or more if you can.

Edited April 4, 2005 by SethG (log)

[Patrick S]

Question for more experienced pizza bakers: can you put the pizza on a very thin metal sheet and set the pizza+sheet on the stone, versus sliding the pizza off of the sheet or peel directly onto the stone? For me the first wat seems much easier -- I don't have to worry about pushing the pizza off the (small) stone, and I only have to keep the oven door open for a couple of seconds. Also, what are some guidelines as far as preheating the stones? For instance, for a 1/2" stone, how long after preheat should you wait before baking?

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Patrick, if you really don't want to slide the pizza, you might try putting your pizza on a sheet of parchment paper on back of a half-sheet pan, and then sliding the paper (with pizza on top) onto the stone. I'd worry that the time spent heating the metal between your stone and your pizza would be detrimental (if only slightly) to your end product.

Sliding pizzas off a peel can be scary, but it is also thrilling! And not so hard once you get the hang of it.

Edit: and heat the stone for a long time. Preheat for an hour or more if you can.

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It's okay to use parchment in a 500 degree oven? I've seen pizza dough recipes that say to do just that, but have never tried it because I thought that it would catch fire or crumble or something.

[SethG]

It's okay to use parchment in a 500 degree oven? I've seen pizza dough recipes that say to do just that, but have never tried it because I thought that it would catch fire or crumble or something.

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I've done it many times with bread. I haven't tried it at 550 (my oven's highest setting) with pizza, but I don't see why not.

[johnnyd]

Well, I have to thank you guys for contributing some thoughts on my yard sale find... And I congratulate those who rolled their eyes in private for being politely quiet!

Unfortunately my oven gets the fire alarm going whenever it's anywhere above 300 and the damned thing is above a stairwell so it's hard to get to. This has prohibited a wide range of cooking that I will definitely fix in my next abode as we are tired of fanning said alarm whnever things get hot. We ended up making a pizza in a cookie sheet that was undercooked after a halfhour.

Besides that, I think this marble will make a pretty good table top. I also have three 12" square marble tiles with a bit of grout left over from their fireplace setting. I'm still willing to experiment, alarm be-damned, with one of these. I don't think this stuff is going to shatter at even 500, crack maybe, but not shatter.

[Shalmanese]

another thing: Is it really a big deal if a pizza stone cracks? After all, it still has the same thermal mass and theres a negligible decrease in contact area.

[jsolomon]

another thing: Is it really a big deal if a pizza stone cracks? After all, it still has the same thermal mass and theres a negligible decrease in contact area.

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As long as you're talking about equilibrium thermodynamics (read: everything has come up to temperature properly) mass is mass. You could smash your pizza stone into sand and it would still provide the same thermal performance. For that matter, you could put a bunch of sand between two aluminum pizza pans, weld them together, and still have a good pizza pan, thermal-mass-wise.

[scott123]

another thing: Is it really a big deal if a pizza stone cracks? After all, it still has the same thermal mass and theres a negligible decrease in contact area.

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I think you might be picturing one perfect crack right down the middle of a stone. A crack from thermal shock can occur in a countless number of ways, depending on where the points of weakness in the stone are located. If an imperfection lies near the surface, a chip could flake off. When you remove the pizza, the peel could drive this chip into the crust. Is this probable? Not terribly. But if you bake with materials that aren't made for baking, the probability increases.

If I can forgo granite/marble/quarry tiles and spend 1 or 2 dollars (literally) more on fire brick and have some additional piece of mind that a shard isn't going to chip a tooth, then definitely, 1 or 2 dollars it is.

Edited April 4, 2005 by scott123 (log)

[natasha1270]

Johnny - While marble as pizza stone seems not like a good idea, you could still use the marble for pastry/chocolate work if you are so inclined.

N.

[johnnyd]

Cool!

[Shalmanese]

another thing: Is it really a big deal if a pizza stone cracks? After all, it still has the same thermal mass and theres a negligible decrease in contact area.

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As long as you're talking about equilibrium thermodynamics (read: everything has come up to temperature properly) mass is mass. You could smash your pizza stone into sand and it would still provide the same thermal performance. For that matter, you could put a bunch of sand between two aluminum pizza pans, weld them together, and still have a good pizza pan, thermal-mass-wise.

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No, because you also have to take conductivity into account. Put a pizza stone and a cast iron pan into a 500F oven and let it come into equilibrium. Touch your finger on the pizza stone for 2 seconds and touch in on the pan for 2 seconds for a graphic demonstration of thermal conductivity.

In addition, contact area also plays a role. I suspect that placing it on sand would cook it just as well except you would get a different pattern of browning on the bottom of your pan.

[Gul_Dekar]

Besides the pizza stones one can buy from kitchen stores, what other materials make good baking stones? I've been trying to find unglazed quarry tiles but so far haven't had much luck. I've noticed places that sell untreated slate tiles. Are these usable for said purpose? Only info I could find about slate is here. It says its thermally stable and chemically inert. So is it a good alternative to quarry tiles?

[uberleet]

Besides the pizza stones one can buy from kitchen stores, what other materials make good baking stones? I've been trying to find unglazed quarry tiles but so far haven't had much luck. I've noticed places that sell untreated slate tiles. Are these usable for said purpose? Only info I could find about slate is here. It says its thermally stable and chemically inert. So is it a good alternative to quarry tiles?

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I got some 3/4 inch thick Saltillo tile from Home Depot; it runs about 90 cents for a 12x12 tile. You can cut it to size with a skilsaw or jigsaw. It does occasionally crack under high heat (over 500), though I've only had one crack and it is still usable.

Untreated slate should work fine. Another option is Fibrament, though it's a little more expensive.

[andiesenji]

Slate is not stable in high heat, flakes will pop off. Quarry tile is manufactured and is heat stable.

1/2 thick firebrick (used to line fireplaces) will also work, simply take a sheet pan that fits your oven along with you and fit them into it.

There are several types of manufactured stones that work very well and are completely heat stable.

Check these at Amazon.

I use one of the round ones in my Sharp convection/microwave oven - the 15 inch round just fits the metal revolving tray. I have a Hearthkit for my big oven but haven't used it in a while.

If you want something that is a natural stone and if there is a monument place in your area (gravestones) call and see if they have any thin (1 to 1 1/2 inch) slabs of soapstone, it is heat stable.

Edited February 25, 2006 by andiesenji (log)

[Woods]

Besides the pizza stones one can buy from kitchen stores, what other materials make good baking stones? I've been trying to find unglazed quarry tiles but so far haven't had much luck. I've noticed places that sell untreated slate tiles. Are these usable for said purpose? Only info I could find about slate is here. It says its thermally stable and chemically inert. So is it a good alternative to quarry tiles?

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I have been using unglazed quarry tiles, as they call them at tile shops. Mine are 8"x8" and so far have lasted close to ten years.

[rjwong]

FYI Here's a link to an LA Times article (22 Feb. 2006), Soapstone: : Cookware that Rocks

In the article is a list of soapstone distributors:

Wildwood Ovens

Fante's

Greenfeet

Brazil on My Mind

Medagliani l'Alberghiera, Milan (Soapstone ware is on Page 7)

I hope this helps.

[scott123]

It does occasionally crack under high heat (over 500), though I've only had one crack and it is still usable.

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I wouldn't recommend using a cracked stone to bake with. A cracked stone is a structurally weakened stone. A structurally weakened stone is much more prone to leaving shards/bits of rock in your baked goods. As hard as your teeth are, these pieces of stone are harder. I know.

[scott123]

Besides the pizza stones one can buy from kitchen stores, what other materials make good baking stones? I've been trying to find unglazed quarry tiles but so far haven't had much luck. I've noticed places that sell untreated slate tiles. Are these usable for said purpose? Only info I could find about slate is here. It says its thermally stable and chemically inert. So is it a good alternative to quarry tiles?

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Quarry tiles aren't the best choice because they aren't always made to handle the thermal shock of baking. Soapstone is ideal, but is extremely expensive. Fire brick is what most wood burning ovens are made from. Look in the yellow pages under brick and call places until you find someone that sells it. Fire brick IS made to handle the thermal shock of baking and is only slightly more costly than quarry tile.

Edited February 25, 2006 by scott123 (log)

[andiesenji]

My housekeeper just reminded me that you can also get pieces of soapstone from places that supply kitchen countertops. My contractor showed us several pieces of granite and a slab of soapstone in his truck that were left over from cutting out holes for sinks. He had gotten them from the countertop place, in exchange for some work, and planned on setting them in concrete to make a patio table. I admired the soapstone because that particular piece was a very pretty pale sage green.