[Crossposted to rec.food.equipment and rec.food.baking; followups
redirected to rec.food.equipment only.]

Yes, I've searched newsgroup archives, yes I've read all the arguments
that unglazed quarry tiles are safe, and yes I've been baking directly
on them for years and I'm still alive. But the time has come for my
wife and I to see if we can pass our genes on to the next generation,
and so we're being intentionally paranoid about food safety issues.
From what I've read, the argument that they're safe seems to be that
there's no evidence that they're not safe, and nobody has died or
gotten sick or lost IQ points because of them (as far as we know), so
there are more important things to worry about: they're innocent until
proven guilty.

My quarry tiles are dark red-orange in color. Red to me means most
likely iron, but perhaps cadmium. And who knows what else is in
there. Maybe lead, maybe not. Maybe whatever's in there won't
transfer to the bread anyway, but then I do bake mostly sourdough,
which is a bit acidic. I don't know the origin of the clay used to
make my tiles -- maybe it was Mexico or China, where perhaps the
regulations about lead and heavy metals are a bit more lax. That's
enough maybes for me that, being intentionally paranoid, I'm going to
take a "guilty until proven innocent" stance. Unless anybody can
point me to a supplier of tiles who will actually vouch for the
composition of their product, down to trace elements in the
single-digit ppm (parts per million) range, or else another reliable
source of evidence that they're safe, I'm going to replace my trusty
old quarry tiles with something NSF or FDA approved.

FLAME-RETARDANT DISCLAIMER: I'm not saying that quarry tiles aren't
safe -- I believe they probably are, and have no evidence to the
contrary -- but I'm just being paranoid. I don't encourage anybody
else to throw away their quarry tiles and buy an expensive baking
stone. If anybody can actually provide evidence to prove the
innocence of quarry tiles, I would be truly grateful, because they
work well and are cheap.

So on to what to replace it with -- there seem to be two contenders
for the home baker: the commonly available cordierite "pizza stones",
and the FibraMent stone from AWMCO (www.bakingstone.com). The former
is half the price, but the largest size I can find is 14"x16" --
that's not enough room for two boules, and barely enough room for a
moderate size pizza. I really need to completely cover my rack except
for a little room for air flow -- which makes 16"x20.5" the ideal
size. The FibraMent comes in a standard 15"X20", which is very close.
For the price of the FibraMent, I could get two (slightly thicker)
cordierite stones and cut one so that I had exactly the size I want,
albeit with one seam. (But add the expense of taking the stone to a
hardware store to be cut, as I don't have a tile saw.)

On the other hand, I once owned a cheap baking stone (probably
cordierite, but I'm not sure), which cracked after only a few months
of use, and I took what I thought was good care of it -- avoiding
putting water on a hot stone, and always preheating the oven with the
stone in it. The greatest stress was caused by transferring the
(cool) stone in and out of the oven, since I don't want it in there
when I'm only using the oven to quickly roast some vegetables, for
example, because pre-heating the stone is a waste of time and energy
in that case. Anybody who's owned a FibraMent for a while care to
comment on its durability, or on what hoops you have to jump through
to take advantage of their 10-year warranty?

Anybody care to comment on baking characteristics of cordierite
vs. FibraMent?

TIA for any info/advice,

--
Randall Nortman