Seasoning Your Cast Iron

Seasoning is the black patina that builds up on your cast iron cookware with regular use.  It is created when long chains of fat molecules break down into short-chain polymers that bond with naturally produced carbon and bare iron when subjected to high heat. This process forms a natural barrier between the air and the naked iron on your cookware, acting as the first line of defense against rust.  It also creates a non-stick surface that’s slick enough for eggs to skate across, but tough enough to withstand the blazing heat needed to properly sear a steak. 

Use Your Cast Iron

Seasoning will develop over time, layer by layer every time you use your cast iron.  The best way to build seasoning is to simply cook with your cast iron as often as you can. Every time you heat oil or fat for an extended period of time in cast iron, you add a thin, durable patch of seasoning. These thin layers build on each other like coats of paint on a wall, slowly but surely, forming a resilient, ultra-slick surface.  Meal after meal, you will be adding to your cast iron’s seasoning and improving its performance.

Coat with Fredericksburg Cast Iron Co. Proprietary Seasoning Blend or Oil of Choice

Periodically, after cooking in your cast iron and cleaning it, follow these simple steps to enhance the natural seasoning process:

1. On cook top heat skillet on medium heat until hot (1-3 minutes)
2. Turn off heat
3. Apply a dab of our Seasoning Blend or your high smoke point oil of choice to the inside of the cast iron
4. Carefully, as cast iron will be hot, with a paper towel rub the Fredericksburg Cast Iron Co. Proprietary Seasoning Blend or oil into the cooking surface, and bottom of your cast iron.

This step with our Fredericksburg Cast Iron Co. Proprietary Seasoning Blend or oil will help build durable, non-stick seasoning. Good seasoning that lasts is built in thin layers.  

The best fat polymerization comes from oils rich in polyunsaturated fatty acids—the compounds that give ‘drying oils’ the ability to thicken and harden once exposed to air. After testing dozens of seasoning methods with all kinds of fats, we recommend our Fredericksburg Cast Iron Co. Proprietary Seasoning Blend which is made with avocado oil, Texas beeswax and extra virgin olive oil since it breaks down into tough but thin coats of seasoning that build well on each other over time.

Seasoning Cast Iron in the Oven

If you want to take your seasoning to the next level, by more quickly building a durable seasoning coating, seasoning in the oven is a good method.  While it can be beneficial to do this process periodically it is definitely not required.  Some cast iron owners do this for every new piece of cookware they get, and then repeat the process every few months or years. Others never bother, opting for a slow and steady “keep cooking” policy.

After testing every technique out there, we have developed an approach based on gradually boosting the temperature of the cookware to bake the seasoning into the surface, not just on top of it. When using this method, ideal seasoning temperature is just below the smoke point of the oil being used, the point where the blend or oil breaks down into carbon and short-chain polymers that can bond with the cast iron. Below that point for too short a time, and the oil won’t fully polymerize; above that point for too long, and the oil runs the risk of skipping past the polymer stage and straight into completely burnt carbon.  The following steps outline an effective process for this method:

1.Preheat your oven to 200˚ F.

2. Clean cast iron cookware thoroughly with a little dish soap and water.

3. Heat your clean cast iron on the stove for 5 minutes to evaporate any lingering moisture.

4. Once the oven is up to temperature, put the cast iron in for 10 minutes.  Pre-heating this way ensures it is completely dry and opens the iron’s pores to better absorb seasoning.

5. After 10 minutes remove the cast iron and increase the heat to 300˚ F.

6. Apply Fredericksburg Cast Iron Co. Proprietary Seasoning Blend to your cast iron.  Add a dab (~1/8 teaspoon) of our Fredericksburg Cast Iron Co. Proprietary Seasoning Blend or oil to the cooking surface of your cast iron.   Use a clean paper towel to rub the Seasoning Blend or oil in concentric circles, then take a fresh paper towel and wipe up all the residue. Repeat on the bottom and handle with another ¼ teaspoon dab of Seasoning Blend or oil.  When you’re done wiping up the excess, the cast iron should look dry, with a dull matte finish. Though it might not look it, plenty of Fredericksburg Cast Iron Co. Proprietary Seasoning Blend or oil will still be on the cast iron, just in a super-thin layer, which is exactly what you want. Remember, your goal is to bake a layer of seasoning into the cast iron, not on top of it.

7. Once the oven hits 300˚ F, place the cast iron on the middle rack, upside down, which will prevent any oil from pooling at the edge of the cooking surface. After 10 minutes, remove the cast iron, place it on the stove, and carefully wipe away any oil that has accrued on the surface.

8. Increase the heat to 500˚ F. and when it hits temperature, return the cast iron to the oven and leave it alone for an hour. To keep the heat constant, don’t open the oven at all - Leave it alone. 

9. After 1 hour, remove from oven and let cool.

Oven seasoning cast iron once doesn’t mean it’s good to go forever. You can repeat this process a couple times, but your best bet for developing a glossy patina is to just cook with the cast iron. Now that you have a strong base layer of seasoning firmly bonded to the cast iron, your job is to reinforce it with the ultra-thin layers that result from everyday cooking. 

Do I Need to Season a Pre-Seasoned Skillet?

These days, most cast iron manufacturers pre-season cast iron, us included. You can cook with this cast iron right out of the box, but they won’t actually be totally non-stick. Your Fredericksburg Cast Iron Co. cookware comes coated with an avocado oil pre-seasoned layer which is baked into the cast iron, not on top of it. We’ve found this approach develops better subsequent layers of seasoning over time, compared to other cast iron pieces that try and speed up the process by covering up the iron with a more cosmetic top coat.  Early in the lifetime of your cast iron, some proteins like bacon and eggs may stick a bit. This is fine, and all part of the gradual seasoning process. The most important thing to do is cook with it often.

Avoid acidic and long-simmered foods

Tomatoes, wine, citrus, and vinegar can eat away at seasoning, so keep the tomato sauce out and avoid deglazing with a new piece of cast iron cookware. A lightly seasoned cast iron piece may even add unpleasant ferrous flavors to acidic foods. However, once you have completed the breaking-in stage and seasoning is producing reliable non-stick performance, a little acid here and there isn’t a problem.  Acidic foods like lemon, tomatoes, wine, and vinegar will eat away at seasoning, leaving a patchy cooking surface, but occassionally cooking with these foods will not damage your cast iron. 

Great cast iron seasoning — and patina — comes from time and use. If you cook with your skillet regularly, you will steadily develop a beautiful non-stick cooking surface.