How to prepare and season cast iron cookware
Adriad Marshall
for reference purposes. People have been asking me how to deal with
these things, and the instructions in the posts I've found on Usenet
on the care and feeding of cast iron cookware are either incomplete or
in most cases, incompetent. That includes the instructions that come
with the cookware. Although my instructions focus on preparing new
cast iron skillets (because I bought a cheap taiwanese skillet
recently), it also applies to any piece cast iron cookware, old or
new.
1. PREPARING THE SKILLET FOR SEASONING:
Most cast iron skillets etc. are protected by a rust-inhibiting
coating, which you may not see or feel. Burn it off. To do this, put
it on an element closest in size to the utensil you are preparing (but
not smaller), turn the heat to MED., and that setting should be hot
enough to enable the coating to smoke off. Be patient, this can take
20-30 min., but when there is absolutely no more smoke coming off the
cookware, it's ready to be seasoned. (n.b. You may crank up the heat a
little past MED. if indeed you do have a protective coating on your
piece and you do not see it burning off after a few min. on MED. But
it is not a good idea to abuse an empty cast iron skillet with higher
heat. Remember that the longer you leave cast iron on the element, the
hotter it gets).
Place the skillet on a trivet and let it cool down slowly and
naturally. When cool or only warm, wash the vessel in warm or hot
soapy water, scrubbing vigorously with a fine steel wool pad (ie. "SOS
pad"). Rinse well, making sure to remove all fibres left by the pad.
Drain the remaining water and dry on the lowest setting on your
stovetop element or in your oven, until all moisture has evaporated.
(see notes #1, 2 below)
2. SEASONING THE CAST IRON COOKWARE
Preheat the oven to 500F. Melt 1T-2T (depending on the size of the
utensil) of solid vegetable shortening (I use the microwave). (Lard is
actually better, but because it's an animal fat, I wouldn't recommend
it unless you're going to use the piece often). Ensure the cookware is
still warm (if not, place it in a heated oven). Ideally, it should be
about as hot as you can stand to touch it with your bare hands. Then
pour in about half the melted shortening into the interior of the
vessel. There should be a fairly generous amount, so you have no
problem spreading it out over the surfaces of the interior with a
paper towel. Rub well over the entire interior, including the top lip.
Then with another dry piece of paper towel, remove the oil you just
rubbed in.
Turn the vessel over and pour the rest of the shortening over the
bottom exterior. Spread it over the entire exterior with a paper
towel, then go over it with a dry piece of paper towel, removing the
excess oil. Repeat the oiling/drying process on the vessel's handles,
going over every nook and cranny. (For safety reasons, I like to do
the handles last, so they are dry while I'm holding the piece).
Finally, I like to go over the entire utensil lightly, with another
piece of paper towel, to ensure there are no "glops" of shortening,
and all excess has been removed. At the end of this process, place the
utensil in the oven for 1 hour. Turn the heat off and let it cool down
in the oven (which will take a few hours). Once cool (or slightly
warm), wash in warm (or somewhat hot) water, scrubbing vigorously with
a nylon puff scrubber. Let it dry for a few min. on the lowest setting
of a stovetop element. Once dry, repeat the seasoning process above a
second time (which will help strenghten the seasoning, particularly
since the first coat is a thin one). The cast iron utensil should now
be a deep chocolate brown color, with an even coating throughout. (see
note #3)
3. USING AND CLEANING THE CAST IRON COOKWARE
It is best to cook mainly with fats (ie. butter, margarine, oil, meat,
etc). the first few times you use the piece, to help keep the
seasoning intact and strengthen it. Avoid boiling water or acidic
ingredients like tomato, lemon juice, etc. during this period. The
goal is to strengthen the seasoning (called "developing a 'patina'),
so that the coating will eventually be more forgiving of abuse (which
can occur from cooking anything besides fatty/oily/greasy foods, using
high heats or metal cooking utensils). The patina requires years to
fully develop (to completely seal the pores of the metal), but once it
has, it feels a lot like the glassy enamel exterior of a Creuset
piece. It is a very durable stickless surface that will outlast any
PTFE nonstick coating.
The trick to building this protective patina is not ever using soap to
wash the vessel, and using the piece more or less regularly. Because
the skillet has been properly seasoned and you're cooking mainly with
fats at the beginning, it will be easy to clean. Use a nylon puff pad
and warm to somehwat hot water to clean it, then dry on the lowest
heat setting on your stovetop until the moisture has evaporated. (If
there is residue stuck on that the puff is not easily removing, either
try a plastic scraper or soak it in warm water only for no more than a
few min.). If you're in a humid climate, you may need to place a piece
of paper towel in the vessel to absorb moisture and prevent rust
during storage. Before cooking with my CI cookware, I like to give the
interior a quick water rinse, then preheat it on LOW to MED., at least
until all moisture has evaporated. (see note #4)
4. REMOVING THE SEASONING
I won't get into removing stubborn rust from junkyard cast iron
"finds" here, since there's plenty of guys with power tools who have
posted endlessly on this very subject on usenet. But if for some
reason you need to completely remove the seasoning from your cast iron
piece, one easy way is to throw it in a fire until it has burnt off.
(n.b. #1: Some advocate scrubbing to remove the manufacturer's
protective coating. In my experience, that won't do. Even after
washing and drying the skillet several times, using an abrasive copper
scrubber and detergent, the coating still remained in the pores of the
skillet. It only came out after the vessel was warmed up. At which
point, although it looked clean, wiping the skillet with a white paper
towel left black smudge marks from the protective coating. The only
sure way you can know whether any coating remains is to see if
anything smokes off).
(n.b. #2: DO NOT boil water in the vessel until it is seasoned! You
will have an instant rust problem. This occurred with me after I
boiled water in the unseasoned skillet to remove traces of a harsh
detergent. Which resulted in a "rust ring" around the water line and
oxidation throughout the interior below that level, and even on the
exterior bottom of the skillet. Scrubbing with steel wool and soap
didn't remove the oxidation; it returned as soon as the skillet was
left to dry on the element, even after repeated washes. If this ever
occurs, scrub the dry utensil with steel wool and vinegar. Rinse, dry,
repeat for good measure. Then season and once properly seasoned and
cared for, rust won't be a problem).
(n.b. #3: It is presumed that your cast iron piece does not have a
wooden handle. Some skillets do, in which case, you can't put it in a
500 degree oven. You can probably get away with 350F-400F, if you wrap
a few doses of aluminum foil around the handle. Maybe 450F, but that's
chancy).
(n.b. #4: Some fanatics advocate not using water at all to clean the
vessel, only a wipe down with a paper towel. I think that's really
pushing it! These are likely the same sort that rinse their salad
greens in their washing machine. It's one thing to allow conditions
that might create a possible breeding ground for bacteria. It's
another thing to organize a party for them and invite all of them to
it).