"Becky" <chatham6@cds1.net> wrote:
> I have finally made an excellent pizza in my home oven by preheating
> my Pampered Chef baking stone on the bottom rack (about 2" above the
> floor) at 550 F for 30 minutes. I transferred the pizza to the stone
> with a pizza peel dusted with semolina, and in 5 minutes we had
> awesome pizza :-)
> Now that I think I have the technique down, I'm looking to expand a
> little, and I'm wondering what the best way to do that is. I can buy
> another rectangular stone and put them side by side in the oven, but I
> was wondering about unglazed tiles. I know there must be more than
> one person out there who uses them, but I'm a little leery about lead
> in the clay and so forth. Is there a source out there for food-grade
> bricks or tiles? Or is there some way to determine the lead content
> of tiles that are purchased from the local tile store? I'm thinking
> that if I can get the right size ones, I can just leave them on the
> bottom rack all the time - anybody ever run into any problems doing
> this? I would think that it would be fine, and in fact might help
> retain heat.
The issue with clay isn't the clay, it's the glaze. Clay doesn't have
significant amounts of lead. However, many glazes do. When a glaze is
fired, the lead is supposed to be bound and non-reactive. However, this
requires that all the glaze reach a certain temperature. Cheap tiles from
third world nations often don't reach the right temperatures, evenly
enough, or long enough. Which is why there are warnings against using the
beautiful pottery you bought in Mexico for food.
The second issue is cracking of the glaze. When it cracks, lower levels of
the glaze are available, and lead can be leached out of that.
The bottom line is that unglazed tiles are safe. Ask a hardware store or
flooring store for unglazed quarry tiles. They'll know what you're looking
for.
A final comment on lead - the last time that this issue came up in
rec.food.baking, I spent a weekend surfing the net looking for ANY
indication that there was a problem with lead in clay tiles. I found
none. I then asked my wife, who was a biologist in a former life and is
currently a librarian, to look too. No evidence of lead in clay. At that
point I asked the rather obnoxious poster in rec.food.baking who had
claimed that lead was an issue for ANY evidence that lead in clay was a
problem. Neither he, nor anyone else, came forward with any evidence.
Correlating, suggestive, evidence. Clay tiles are baked at temperatures
that your oven won't reach, even in its self-clean cycle. Anything in the
tiles has been pretty well neutralized. It takes an acid solution and
exposure time to leach lead out of tiles. When you drop a semi-solid loaf
of bread on hot tiles, the surface seals at once, so there isn't much time
for lead pickup, even if there was lead there, which there isn't.
As to baking with tiles, I usually leave my tiles in the oven. I've
covered both racks with tiles. The only drawback is it takes the oven
longer to heat up than it does without. I was in a hurry this morning to
make some sourdough blueberry muffins, so the tiles came out. The muffins
also came out ... nicely, that is.
Mike
--
Mike Avery
MAvery@mail.otherwhen.com
ICQ: 16241692 AOL IM: MAvery81230
Phone: 970-642-0282