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iron leaching in glazes - or in iron skillets...(

updated wed 21 apr 04


Ivor and Olive Lewis on wed 21 apr 04

Dear Friends,
Are we being fair comparing an Iron bearing glaze to a Cast Iron
cooking utensil?
And in the case of a gaze, just how much of the chemicals are exposed
at the surface. Think about a glaze with 5% copper oxide as used by
Ron and John for their definitive tests which show that leachate may
contain upwards of 20 milligrams per litre. That is 20 parts per
million from a glaze which contains 50,000 parts per million of copper
oxide (5% Cu2O). Just think, we have left 48,000 parts per million
remaining in the glaze ! !
Could the same be supposed for a glaze with 5% Iron oxide. After all,
iron oxide does form a citrate!
So what happens when we use an Iron utensil. Common practice is to
season it, put in oil or fat and heat it to a smoking temperature
which bakes some of the fat into a lacquer on the iron surface. Some
of the oil penetrates into the grain of the metal helping to secure
the baked surface to the iron. Unless we scour or scratch through this
it will remain impervious to the fluids that distil out of the cooking
Perhaps we should try to keep a rational perspective.
Best regards,
Ivor Lewis. Redhill, South Australia

----- Original Message -----
Sent: Tuesday, 20 April 2004 1:42
Subject: Re: Iron leaching in glazes - or in Iron skillets...(or,)
I-Ron-ic...and I-Ron-ee, together in per-fect har-mow-knee...

> Hi Lee,
> I think here too, your mention of 'seasoning' Ceramics, is
> very much near the heart of those unfortunate concerns and
> conflicts of Glaze safety, as now-a-days have to be
> addressed in new ways, as to be obliged to anticipate an
> illiterate usage, or, an ill advised one.
> As grateful as I am, for the knowledge we need as so many on
> this List advocate and make our Glazes as 'safe'
> as our wits and methods can reach to do. I am also sad if I
> imagine a neglect of the old knowledges of things' proper
> uses as the vessels themselves...or that there may be
> deference and respect to the vessels themselves...even if
> just so we do know, 'how' the right manner of respect was
> found or enjoyed for them...or may be...
> I am certain, and likely you know enough about these matters
> to share some of them with me, that traditionally, in Japan,
> as well as in other areas, the actual chemical
> potentialities of a Glaze to interact with whatever food or
> liquids it may meet, though unknown in those terms at the
> time, were not necessarily the danger we may suppose them to
> be obliged to be now, when something is (or was) 'seasoned'
> correctly, and or by various deferential, old, impirical or
> intuitive laise faire ways.
> ...even as we may say of a happy, well seasoned, Iron
> 'skillet'...
> A 'Teapot' or a Cup, as is allowed to be or become 'licorice
> brown' inside from long an irritation to people as
> should instead appreciate to leave it alone and respect
> it...on and on...but they will scrub it out...with 'ajax' or
> something...not understanding the matter at all...or,
> offended TO understand all...with all their
> compulsive habits of 'clean'...
> I have known almost no one in the course of my life as did
> in fact practically know 'how' to season and use an Aluminum
> or Enamelled Iron or other Coffee Pot, nor an Iron Skillet,
> properly or well...(but for one fellow as used to be an
> 'egg' cook a long time the 'depression'...)
> As for myself, cooking a decent Spaghetti sauce, or, a
> Bar-b-Que sauce, in one of my Iron skillets, about stretched
> the limits of what I could do with fact, I
> learned to cut the time short for the simmer, but learned as
> well to make these sauces in the time the Skillet would
> abide...and make them well, too, lest, as you say, the taste
> of the (by then) 'exposed' Iron should taint the
> meal...which it will, too, if too much time is allowed the
> acidic sauce to be rest or at 'simmer'...
> I know for me also, I can smell the Iron in a 'raw'
> skillet...
> Anyway...
> The endless little things, and small deferences... of 'how
> to live'...
> Phil
> el of vee
> ----- Original Message -----
> From: "Lee Love"
> > On 2004/04/20 7:44:00, Phil wrote:
> >
> > > I do not believe that a properly 'seasoned' Iron
> Skillet would be
> > found to leach...
> >
> >
> > 8-) You know, there are traditional ways of
> "seasoning" pots
> > too. This is an important practice with both ceramics
> and lacquer,
> > especially in lacquer. The proper use of pottery is very
> similar to
> > the proper use of a seasoned iron skillet, which I am
> sure, fewer people
> > understand now-a-daze, because of the wide spread use of
> stainless,
> > aluminum and Teflon.
> >
> > But to the point: A well seasoned iron skillet will
> leach if you
> > put tomato sauce in it and leave it there. You can tell,
> because you
> > can taste the iron in the sauce and can see the effect on
> the iron
> > skillet after cooking with it. Disgusting taste. I
> learned quickly,
> > for the sake of the sauce and the skillet both, to brew
> these acidic
> > foods in stainless instead.
> >
> > Lee in Mashiko, Japan
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