Seasoning Cast Iron

A few weeks ago I found this beautiful enameled cast iron skillet on sale for thirty dollars, marked down from $90. I was so excited because I'd never had a cast iron skillet before and never cooked in one either. I was giddy thinking of all the possibilities: skillet corn bread, bacon, roasted potatoes, steaks...wow, what else can I cook in it? What are the rules? How do I clean it..Oh wait, before I can clean it, how do I season this pan to get it ready for use?

I went on a mission to educate myself on cast iron. First order of business, How to season this pan? The Internet was filled with all kinds of information on seasoning cast iron and after reading a few sites, they basically end up contradicting the next, each saying their way was best. Basically, you can use any type of oil to season your pan. Finally, I came across Sheryl Canter's website. She used a science-based approach to season cast iron where she considered the chemistry of oils and recommends using Flax Seed Oil for seasoning cast iron. She goes into her reasoning and the chemistry on her page. Now, this is a website I can sink my scientific teeth into. Many lifetimes ago I graduated from UCLA with a Biochemistry degree, so this type of information really spoke to my inner-nerd and sealed my decision to use Sheryl Canter's technique to season my cast iron skillet.

Her web page has tons of useful information and make sure to read the comments section, I read through all the comments and there was some really great information there too. Here is the link to her website. 
http://sherylcanter.com/wordpress/2010/01/a-science-based-technique-for-seasoning-cast-iron/

Seasoning Cast Iron
Here's a much simplified Chemistry lesson...In a nutshell, seasoning cast iron involves coating the pan with oil and heating the pan to very high temperatures (450-500+ degrees) in order to polymerize the fat. When fats/oils are super heated, a part of the fat molecule is cleaved off which creates a highly reactive molecule with an unpaired electron (free radical). The liberation of the free radical allows the fat molecules to change orientation and cross link (polymerize) with each other. The polymerization changes the properties of the oil from a clear, light yellow liquid into an extremely hard, slick, black substance. As we all have experienced when cleaning our ovens or BBQ grills, overheated or polymerized fat is no easy clean up job. That stuff is cemented on there. Not good for ovens but great for cast iron and that's the barrier we want, hard, slick and tough to remove. According to Sheryl Canter, Flax Oil will give you the hardest, slickest surface.

I picked up this bottle from The Vitamin Shoppe for about $11.
It's found in the refrigerated section because this oil goes rancid quickly. (Please do not confuse Flax Oil with Linseed Oil, Flax Oil is edible and available in Health food stores and Linseed Oil is not edible and found in Hardware stores. Both are derived from Flax Seeds.)

Now we are ready to season cast iron with Flax Oil.

Step 1: Make sure your pan is completely dry by placing the pan in a 200 degree oven for 10-15 minutes. Allow to cool enough to touch and proceed to Step 2.


Step 2: Add 1-2 Tbsp of Flax Seed Oil to pan. Rub in with hands to ensure complete coverage of cast iron surfaces.

 

Step  3: Wipe off all excess oil with a paper towel until it's dry looking with no slick oily surface. The pan is still coated with a thin layer of flax oil but you don't want any excess oil to cause drips.

 

Step 4: Place pan upside down in a cold oven and turn temperature as high as your oven will go. I set mine to 520 degrees. My oven goes to 550 degrees but my smoke detectors go off at that range so I adjusted down. Allow oven to reach temperature and then heat pan for 1 hour at 520 degrees. After one hour, turn oven off and let the pan sit in oven for two hours.  Now the pan will be cool enough to touch. Remove pan and repeat steps 2-4. a minimum of 6 times. (Gasp??? What?) Yes, It took me a week and in fact I repeated this 7 times and look, my pan is absolutely stunning!

 

Cleaning Cast Iron
Next question about cast iron...How to clean it? I'd heard from numerous folks to never use soap, only hot water to clean a seasoned cast iron pan. That just didn't sound right to me because to cook with this baby, you have to use oil even with seasoning, this pan is not a Teflon pan so food will stick if you don't add oil. I imagined cooking bacon in it and not cleaning it with soap... won't everything else you cook in it have that faint bacon flavor. Okay so here's the deal. The seasoning is hard and will not come off with soap. Just think of your oven splatters, those don't come off easily with soap.
After I seasoned my pan, I cooked the most incredible roasted potatoes with bacon and Parmesan cheese in my new pan. I wanted to really test the surface and also test how to clean my new pan.
See my roasted potatoes, beautiful huh? They were divine!

Cleaning was a breeze. I wiped out the excess food with a paper towel. My pan's non-stick ability passed with flying colors since all that cheese and bacon came right off with no elbow grease. I added some liquid detergent to a cellulose sponge and cleaned it as I would any other pan and rinsed well with warm water. I dried it with a towel and then popped it into a 200 degree oven for 15 minutes to completely dry pan. I added about a teaspoon of olive oil and spread it all over the pan with a clean paper towel. Now the pan is clean and oiled ready for the next use. (Note: Do not use Flax Oil to coat your pan after cleaning. Flax oil is used for the seasoning process but shouldn't be used for cooking, two different things entirely) Also DO NOT soak your pan in water overnight, this will weaken the seasoning. Clean your pan right away and ensure it is completely dry by putting it in a warm oven before putting it away.

 

What can't I cook in a Seasoned Cast Iron Pan?

Seasoning protects the iron from rusting and provides some non-stick properties. The seasoning is hard and strong but it's not impervious to degradation. Certain foods will weaken the seasoning and cause it to flake off. Here are the rules:
It is not recommended to cook anything acidic in cast iron pans. Foods with vinegar in it, which includes marinades, so be vigilant and use another pan if you have a highly marinated meat. Tomato based ingredients, lemon and wine are also not recommended.
Also you don't want to braise anything in a seasoned cast iron pan. If you want to braise in cast iron, make sure it's a fully enameled cast iron dutch oven,not seasoned cast iron.

And that is it! Enjoy cooking in Cast Iron! Look out for my Roasted Potatoes with Bacon and Parmesan Cheese recipe. I'll post it next!