How to Restore Cast Iron Cookware
Cast iron that is properly “seasoned” and cared for will give generations of cooking service, but perhaps you’ve inherited some cast iron from grandma, or picked some up at a garage sale, that has seen a lifetime of abuse, resulting in layers of baked-on grease and rust. Don’t fret, because even the roughest cast iron can be rejuvenated and put back into kitchen duty! It isn’t hard to repair gunky cast iron cookware, and then keep it in top shape for use afterwards.
There are many methods people use to restore cast iron. Some work better than others, and some can even cause damage to the cookware. An old-timey method is to bury the cookware in the embers of an outdoor fire and let the heat burn off the built-up residue from years of use. While this may work, the intense heat may warp, or even crack, the cookware. Don’t try it on a piece of cast iron that you don’t want to risk damaging!
A more modern method of cleaning years of accumulated grease off of cast iron is to simply put it in a self-cleaning oven during the cleaning cycle. Be sure to let the cookware cool down before you remove it from the oven! Cast iron retains heat very well, and may take a while to cool down enough to handle.
Of course, these two methods will only work if the cookware does not have wooden handles or knobs, but are completely made of iron.
Lye can be used to remove gunk from cast iron, but lye is very corrosive and great care must be used with this method. Be sure to wear protective eyewear and long rubber gloves whenever you handle lye. Using a large plastic garbage can, and add a can of lye for every five gallons of water. Mix the lye and water carefully with a wooden spoon. Tie a strong piece of twine to the cookware and gently lower it into the solution. Cover the can and let it sit for a few days, occasionally checking to see if the gunk has been removed. Your cast iron cookware may look like new again! After removing it from the lye solution, let the cookware drain on newspaper, then wash it well in hot soapy water before re-seasoning it.
You can also spray the cookware with oven-cleaning spray and place it inside a heavy plastic trash bag for a few days. Lye or oven cleaner will not harm the metal, but both have toxic fumes and can cause skin irritation. If you have children or pets, these methods will expose them to dangerous chemicals and you should probably not use them.
A more labor-intensive, but safer, method is to scrape the surface gunk off with an old chisel or other stiff scraper. An electric grinder or abrasive drill attachment can make the job easier. Once the gunk is removed, switch to wet emery cloth or fine steel wool, starting with a rougher grit and working down to a finer one until the surface of the cast iron is smooth.
Now that your cookware is cleaned of years of abuse, you need to re-season it before you use it. Seasoning (or curing) cast iron cookware fills in the microscopic pores and valleys in the metal, giving it a glossy patina and smooth, non-stick surface. Don’t cook foods in cast iron that is not well-seasoned. Food that is exposed to iron may have a metalllic taste, and the metal may discolor and will rust when washed.
Wash the cast iron in hot, soapy water to remove any residue from your cleaning efforts. Dry it thoroughly by placing it on a warm stove burner for a few minutes. When the cast iron is cool enough to handle, coat the entire surface, inside and out, with shortening or animal fat. It’s best not to use liquid vegetable oils, which can leave a sticky surface. Place the coated cookware in a warm oven, about 300 degrees F, for two hours. There may be some smoke, so you’ll want to open windows or turn on the exhaust fan.
If your cookware has wooden handles, you will have to season only the inside of the piece on the stove top, to avoid damaging the wood. You could also season the cookware on the barbecue grill, with the handle extending beyond the edge of the grill.
You may want to re-season the cookware a second time, to improve the non-stick coating. Otherwise, fry in it instead of cooking liquid or high acid foods (which can diminish the non-stick surface) the first few times you use the cookware. The non-stick surface will also improve over time with the right care.
Washing seasoned iron cookware with soapy water will remove the non-stick coating. To clean cast iron, you can simply run hot water over the cooled skillet and scrape any stuck-on bits with a plastic scraper. Never use rough steel wool to clean seasoned cookware, but you may use a mild, non-abrasive cleanser or nylon scrubby if necessary. Dry the cookware completely before storing it.
Depending upon how often it is used, what foods are cooked in it, and the cleaning methods used, the seasoning may eventually wear off. When you notice rust spots or sticking food, it’s time to re-season. Just follow the same methods as before. Some cooks choose to re-season their cast iron cookware each time it is used, but this isn’t really necessary if you avoid using soapy water to clean it after use.
So you don’t need to throw out Grandma’s cast iron, or relegate it to use as a dog food dish. With a little effort and proper care you can use her cast iron cookware for years and then pass it down to your own grandchildren!
