Lili Krakowski on sun 8 jun 08
I stick to the original subject heading as long as the original topic is
"in play." When the discussion has moved on to a related but not direct
matter, I think it easier on the Archives to use a new heading more directly
related to the original topic. Not to pick on anyone, the story of Kelly's
MFA show now has moved to taking girl scouts camping. And like that.
Then: glaze recipes. I am in the process of writing a long, tedious,
informative, if boring, thing on glaze which will, Deo volens, appear on the
Internet sometime.
But to summarize something about glaze.
I opine--have for years--that far too much focus is put on the appearance of
a glaze and its firing temp. as distinguished from its composition. And its
composition is very much like a mocha decoration--where a drop, a root,
appears, and then branches out to "infinity."
When one asks for a recipe one is asking for almost nothing. And--do me
something--I have a low, if amused, opinion of those who won't share.
However. To each his own way of making enemies.
To get back to our best analogy: cooking.
Let us start with a tomato. (Let us start with washing soda--sodium
carbonate. ) A tomato is fine by itself. (Washing soda works fine by
itself) A tomato is not all that nutritious nor that interesting. (Washing
soda will give a finish of sorts, but not a good one.)
Likewise wood ash is fine by itself. Again, not exactly what glaze is all
about.
So we move from the tomato en soit and add something to make it "better".
We add some onion. (We add some silica) We fry the onion (we use a frit
that combines soda and silica) We add eggplant and celery and Summer squash
(marrows to Brits) and on and on...and we get Caponata, Ratatouille, Imam
Baldi. spaghetti sauce and on and on. WE STILL STARTED WITH A TOMATO.
Ok. Glazes all have a basic feature. Soda, potash, ash (let us think of it
as a natural frit), clay. And the dominant material/ingredient is what
determines the final glaze. So we have soda glazes, and ash glazes, and
slip glazes and so on.
Then there are the balancing additives. Soda plus magnesium, strontium,
potash .....The "tree" grows. Suddenly we are in a new place where the
additive is what gives the glaze its character. And what started as a soda
glaze ends as a dolomitic one with the magnesium characteristics dominating
the soda ones.
Same with the tomato. When the dominant ingredient that gives the flavor
now is the eggplant, we have move to a new "family."
Having said all that--I warned you this was tedious--the clay underneath the
glaze is still the biggest factor in glaze results and effects. (I am
talking as someone who still worked with high manganese clay bodies.) And
application, and layering and firing all affect the glaze result. In a
sense the recipe is the least of it.
Which is why I think it SO essential for potters to know what actually is IN
a glaze. Calculation and all that....
Maurice quotes me:
">Today, with digital kilns, it is probably possible that someone will share
>the recipe but not a firing schedule. That I think is fair."
And goes on to say:
" ...I strongly disagree with this...
not the "fair" part, more about what constitutes a recipe. At least
in the sense that mudduck's original query used."
A recipe is the least of it. WHAT would be the point of saying: a pound of
tomatoes, two of eggplant, 1/2 of onion....
without saying what happens next? It used to be that the firing of a fuel
burning kiln-- a skill and craft in and of itself--was what decided what
"finalized" the glaze. In electric kilns the control of the heating and
cooling was not as possible. Today with digital controls an electric kiln
firing can be fine tuned to maximize phases and like that. Hence I think it
likely that someone who has tested for years to achieve THAT result, might
not want to share a firing schedule, but would share the recipe.
Lili Krakowski
Be of good courage
Ivor and Olive Lewis on mon 9 jun 08
Dear Lili Krakowski,
I wish to take advantage of your vast historical knowledge of the
processes and materials used by potters. Perhaps you have an answer to
my inquiry.
Mimi Obstler, in her book "Out of the Earth-Into the Fire." attributes
functions to the main classes of ingredients. To Silica (SiO2) she
attributes the function of Glass Forming, to Alumina (Al2O3) she
attributes the function of Adhesive and to the alkali oxides (Na2O,
CaO etc) she attributes Melting.
I would like to know what it is about Alumina that enables it to
function as an adhesive, as this lady tells us, ".. provides the glue
which holds the molten glaze materials to the clay form... "
Do you know, or does anyone else know the origin of this concept ?
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Steve Slatin on mon 9 jun 08
Lili --
As you already know, hardly anything
can interfere with my inclination to
dispute a point, often with an obscure
bit of information.
Now, you have asked a seemingly valid
question -- "WHAT would be the point of
saying: a pound of
tomatoes, two of eggplant, 1/2 of onion....
without saying what happens next?"
For those of us who collect food
recipes, this is an interesting comment --
as some of the earliest cook books gave
little information even on quantities,
and often less on what happened next, and
the custom of providing a comprehensive
list as part of a recipe is a rather
recent innovation.
Even 50 years ago many recipe books were
full of 'cook until done' instructions,
and 'correct the sauce' guidance. (How,
I wondered as a young lad, does one correct
a sauce? "Bad sauce! Bad sauce! Now
uncurdle and get back to work!") The
earliest cook books we have are especially
odd in seeming to leave at least one
important thing out of each recipe --
one of my favorite recipes (never tried it)
from the Caelius Apicius book begins "Take
a wheelbarrow of rose leaves and pound
in a mortar. Add to it the brains of two
pigs and two thrushes boiled and mixed with
the chopped-up yolk of egg, oil, vinegar,
pepper, and wine. Mix and pour these
together and stew them steadily until
the perfume is developed."
I searched for this recipe in Latin
once, wishing to clarify -- is that one
wheelbarrow of leaves, or of petals? One
egg or many eggs? And seriously, does
the proportion of two whole pigs and
a wheelbarrow of SOMETHING from roses
seem proportionate to the brains of
two thrushes?
But even so, we learn from this recipe
(even if, mercifully, we are not expected
to replicate it). voluminous quantities
of meat, together with truckloads of
produce, can be stewed together, and cooks
from ancient times have relied, as my
pastry chef wife does today, on aromas
to tell them when a dish is ready.
So a recipe alone is not worthless -- it's
just incomplete (imperfect) information.
Everything else you wrote I agree with
heartily.
Best wishes -- Steve Slatin
--- On Sun, 6/8/08, Lili Krakowski wrote:
> From: Lili Krakowski
> Subject: Misc.: Subject headings; recipes
> To: CLAYART@LSV.CERAMICS.ORG
> Date: Sunday, June 8, 2008, 7:14 AM
> I stick to the original subject heading as long as the
> original topic is
> "in play." When the discussion has moved on to a
> related but not direct
John Sankey on tue 10 jun 08
"I think it likely that someone who has tested for years to achieve THAT
result, might not want to share a firing schedule, but would share the
recipe."
That's the reason why I require testers of glaze recipes in the glaze
database to sign their names. A recipe that requires a secret firing method
to work won't be accepted for it.
John Sankey
-------------
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I can only read text mail, no attachments.
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