Don't throw out that cast iron!
by Kathy and Bruce Jacobs
Do you have a piece of cast iron that looks absolutely grimy? ...that is caked with dirt and grease? Don't get rid of it? Clean it! As long as it has no cracks or nicks, you can clean it.
This article applies only to full cast iron. Other techniques need to be used if you are working with cast aluminum or a piece made of one of the hybrid cast metals. Also, this will not work on a piece that is coated with Teflon or other non-stick surface, as it will destroy the non-stick surface.
If the cast iron has any rust visible on the cooking surfaces skip down to Complete Re-Season below. Otherwise, try the following procedures in order. (I have listed them from easiest to hardest.) You have probably already tried some of these ideas.
- Try mild detergent and a wash cloth
- Try 3M-brand Scotch-Brite pads or generic equivalent.
- Try steel wool
- If the area to be cleaned has hard caked on food, scraping with a old screwdriver or small scraper should remove most of it.
- Use sandblasting. This is done by rubbing the pan with either course sandpaper (80 grit), or by rubbing the pan with sand and aluminum foil to remove everything coating the cooking surfaces of the pan.
If during processes 1 through 5, you start to see shiny iron underneath, you will need to re-season the pan when finished. If the pan is clean, but you have not taken the pan down to bare metal, I recommend coating the area lightly with oil and cooking something greasy the next time you use it.
Some people have had good luck cleaning off the worst layers by running it through the self-cleaning cycle of an oven. Do this only at your own risk. I have never tried this as I know that this will void some oven warrantees, including the one on my oven.
No matter what you have done to here, rinse the cast iron in water and dry it thoroughly.
When do you need to do a complete re-season? Any time there is any area where bare metal shows through the existing seasoning.
There are three steps to a complete re-season:
- Coat with a thin layer of vegetable oil (nothing with salt or derived from animals)
- Place upside down in a 350-400 degree oven for about one hour. Upside down is important. The oil may flow somewhat as it gets hot. If it were to pool in the bottom of the pan the excess oil would later need to be removed. (Hot oil may drip off and the process may smell unpleasant)
- Let the piece cool before using
The seasoning is not yet mature, however and can be easily damaged. Always put a thin layer of oil on the cooking surfaces of the metal before using it the first few times. Some foods will remove the seasoning if it is not fully established. Avoid cooking fruit, tomatoes or anything acidic the first couple of times it is used.
So, next time you see a piece of cast iron at a garage sale or auction, you know you can save it. Just remember that this won't do anything for cracked cast. Those pieces can be thrown out!