Seasoning Cast Iron Cookware

Cast Iron Jack McGrew’s Ultimate Method

adapted slightly from:  MelindaLee.com

There is really only one successful way to season a cast-iron cooking utensil, and that is to use it, use it, use it. But until the months and years have passed that are needed to properly do the job through use, the iron must be coated with a layer of something to protect it from rust and to prevent that metallic taste from transferring to the food.

Most manufacturers suggest ways to apply that layer of protection—always a fat of some kind—but most of their instructions are designed to make the job seem easy and to not scare off the buyer, rather than to do the job right. What is really required is a relatively thin layer of pure and simple carbon. Yes, carbonized fat or oil. Carbonized to a hard, smooth surface that seals the utensil from rusting and prevents the iron from exuding that metallic taste, which, by the way, is not harmful just a bit unpleasant. Contrary to some manufacturer’s instructions, that layer of carbon just simply cannot be formed at a temperature of 250 to 350 degrees. The carbonization of that layer of oil takes HIGH heat. Like 500 to 550 degrees.

This is how Cast Iron Jack McGrew treats a brand new cast-iron skillet or other cast-iron cooking utensil:

1. Remove any labels, and if the manufacturer has included some printed instructions on how to season the piece, throw it away quick before you read it. Wash the piece well by hand with regular hand-type dishwashing detergent. Dry it thoroughly. NEVER put cast-iron cookware in the dishwasher.

2. Rub a relatively thin coat of oil all over the piece with the fingertips. Animal fats are not really suitable, as the carbon formed is usually quite soft, not nearly as hard as vegetable oils. One cooking-lady-about-town has always recommended using mineral oil, but since Ol’ Jack doesn’t fry his eggs in mineral oil, he doesn’t use it to season skillets either. Jack himself uses almost any kind of vegetable oil, even bottom-grade olive oil, but generally likes regular Mazola or Wesson type oils the best.

3. Such oils as Wesson oil or Mazola will become tacky as they air dry, and the piece should be allowed to air dry for perhaps two to four days, turned upside down on a newspaper to absorb drips. If an oven with a pilot light is available, its temperature should be about 110 to 120 degrees, and drying in such an oven will speed the process. Once the piece has become tacky to the touch, handling it very carefully so as not to leave fingerprints on the tacky surface, carefully BLOT (don’t wipe) any drips that are not tacky. If the piece has shiny areas that are very tacky, the oil was too thick. If it has almost no tacky feel at all, the oil was too thin. In either case, it can be recoated. The application of new oil will dissolve or thin the oil on those shiny spots and it can then be wiped to a thinner coating. If the coating seems too thin, just add another thin layer.

4. All that remains to be done is to burn that oil coating to a layer of carbon. Put the piece upside down in the oven, with a sheet of aluminum foil on the bottom to catch any drips and turn up the heat. Ol’ Jack, like a lot of other heavy-duty cooks won’t let an electric oven or cooktop through the kitchen door, so his oven is gas. He sets it at 500 degrees and burns that pan for one hour.

5. Yes, you’ll want the exhaust fan on, and all the ventilation you can get. It’s always nice to do a few pieces at once, as the process does smoke up the kitchen, and who wants to do that every week? Let the cast-iron cool slowly in the oven for an hour or two after you turn off the heat, and voila! it’s ready to use. If the carbon coating seems a little thin, the process can be repeated immediately.

No account of Cast Iron Jack McGrew’s Ultimate Method would be complete without some instructions on washing, cleaning, and caring for the cookware after you’ve seasoned it, so take Ol’ Jack’s instructions to heart:

1. Rule #1 is NEVER cook at higher heat than is necessary to do the job.

2. Rule #2 is always try to remember to clean the piece while it’s still hot. If it cools before you get around to cleaning it, it can be reheated. Sometimes a quick shot of a pan coating like PAM and 30 seconds on the burner will work wonders. Other times, just blistering hot water from the sink faucet will suffice.

3. Rule #3 is NEVER do any more cleaning than is necessary. If you’ve just fried a couple of eggs with a squirt of pan spray, at low heat, a quick wipe with a paper towel is probably going to be all that’s necessary.

4. If a quick wipe with a paper towel won’t do the job, hold it under that blistering hot water from the faucet and scrub it briskly with a stiff fiber brush; stiff enough to loosen any bits and pieces of carbonized food sticking to the pan. Remember, what you want that coating to be is carbonized oil, not carbonized groceries.

5. If there are still bits and pieces of carbonized food sticking to the pan, give it a quick swipe with an old, dull copper or stainless steel Chore-Girl. Don’t use a new, sharp one; it’ll scrape off your nice new seasoning. Avoid wire brushes like the plague. Don’t even think about those nice yellow fabric things that have metal particles imbedded in them, and never, never use those space-age plastic scouring pads.

6. If it really becomes necessary to wash the thing in soap and water, go ahead and do it. That age old admonishment to never use soap has been handed down through the generations since “soap” was a home-made commodity consisting of lye and bear grease, and the lye alone was enough to strip the seasoning from a skillet. Modern detergents are about as much wetting agents as anything and have no relationship to what people meant when they said “soap” a hundred years ago. Just wash it in the sink, using your regular hand dishwashing detergent and a stiff bristle brush—or even that old, dull Chore-Girl—dry it carefully, and when you’re done put a few drops of vegetable oil in it and wipe it around with a paper towel until it’s dry. Yes, the paper towel will be black. No, it isn’t dirt. The black is carbon.

7. Eventually, after enough use and proper cleaning, that surface in your skillet will get to be just like Teflon or Silverstone type surfaces. It will require very, very little oil for most cooking.

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