There’s no shortage of opinions about the right way to season a cast iron pan. The trouble is, the more you search, the more conflicting information you’ll find. Add to that the wealth of mythology that surrounds cooking with cast iron, and it’s no wonder people end up confused and overwhelmed.
We’re here to let you know that seasoning a cast iron pan doesn’t have to be complicated and that much of the myth and legend around cast iron cookware can be dispelled with a little background knowledge.
We’ll start with a run-through of the technique for seasoning a cast iron pan the right way, then explain the reasons behind it.
Pre-Seasoned Cast Iron Pans
Many companies who make cast iron pans state their pans are Pre-Seasoned. While this is great for the consumer, after time if not seasoned properly, food will begin to stick to the pan. Pre-seasoned doesn’t mean you will never have to season your pan.
My choice cast iron pans have always been from Lodge. They are inexpensive and have lasted me over 10 years. You can find one for less than $15 on amazon.
How To Season A Cast Iron Pan – The Right Way
Begin by ignoring everything you have ever been told about seasoning, using, and caring for cast iron pans.
Preheat your oven to 450 degrees.
Between the factory and your kitchen, your cast iron pan will collect dust, dirt, and other debris too small for you to see.
So the first step in the process is to wash your cast iron pan with warm soapy water and a soft sponge.
Don’t worry. Despite what you may have read, you can wash your cast iron pan with warm soapy water. It will not damage the surface in any way.
Dry your pan, thoroughly, using some non-shedding paper towel. We’ve found blue shop towels also work well.
For the seasoning process to work it is essential there’s no residual moisture on your pan. So it’s a good idea to stand your pan on a hot stove for a few moments and ensure every last drop of water has evaporated.
Make sure your pan is cool enough to touch then pour in between ⅛ and ¼ teaspoon of oil. Don’t worry if you pour in too much oil; it can be wiped out again.
Rub the oil over the entire surface of your pan, including the bottom and the handle.
There is much debate over what is the “correct” oil to use when seasoning a cast iron pan. Generally speaking, the oil you use is not important; whatever you have in the kitchen is fine.
The exception to this is flaxseed, or any oil blend containing flaxseed. When used for seasoning, flaxseed oil forms a surface that tends to flake, so it is unsuitable for seasoning.
Using your non-shedding kitchen towel, buff your cast iron pan until the entire surface no longer looks greasy and has a dry matte appearance.
There are two potential problems with your finished pan if you fail to remove all of the excess oil.
- If you do not use your pan within the next few days, the excess oil will leave a slightly sticky residue on your pan. This defeats the purpose of seasoning your pan to obtain a smooth, non-stick surface, and you will have to scrub the residue off and start again.
- If you do use your pan within the next few days, the excess oil will tend to carbonize, leaving tiny hard spots on the surface of your pan. Again, this will affect the quality of your non-stick coating, and you will have to start again.
Bake the pan in your preheated oven for 30 minutes. It is crucial that the pan gets hot enough to cause the oil to smoke.
The best results come from leaving the pan upside down on the oven rack. This way, if you have missed any oil in the buffing process, it won’t have the opportunity to sit on the cooking surface and cause any imperfections.
Place a second oven rack underneath, with a sheet of foil to catch any stray drips of oil.
Remove your pan from the oven. Wait until the pan is cool enough to touch safely and repeat the process three or four times, from step four.
Seasoning A Cast Iron Pan – How It Works
Iron is a highly reactive metal, and bare iron will begin to rust in humid air in a matter of minutes. If you were to try and cook in a pan made of bare iron, the food would stick, and your cookware would suffer from rust.
Seasoning creates a smooth non-stick coating which also prevents your pan from rusting.
To understand the importance of each step of the process, it’s useful to know how seasoning works and the role each element of the process plays.
The Chemistry Of Seasoning A Cast Iron Pan
When you heat oil in a pan, several reactions take place. The critical two in the seasoning process are called polymerization and carbonization.
The simple explanation goes like this:
- Polymerization causes the oil to break down, and the molecules join together, forming “mega-molecules.”
While they are forming, these mega-molecules, along with the microscopic impurities in the oil and the pan, stick to the tiny crevices of the cast-iron pan, creating a smooth, thin surface.
- Next is carbonization. By heating the oil past the smoking point, you cause carbonization, which lays down a carbon matrix layer. This layer further protects the polymerized layer you have created.
This second stage of the process is why it is essential to make the pan hot enough for the oil to smoke. If this doesn’t happen, the carbon matrix will not be created.
The Role Of Fats In Seasoning A Cast Iron Pan
There is much debate over which oil to use to season your cast iron pan, or even if you should use oil at all. For instance, some people swear by lard and balk at the use of anything else for seasoning.
In reality, the most significant considerations are whether your fat is predominately saturated or unsaturated, and the smoking point of your fat.
Saturated vs Unsaturated Fat
Unsaturated fats work best for seasoning a cast iron pan. This is because unsaturated fats have less hydrogen, which means fewer non-carbon elements making it easier for the grease to bond with the pan. This results in a smoother surface.
Saturated fats have a higher level of non-carbon elements, making it more difficult for the bonding process to take place. As a result, you will not get as smooth a surface.
The temperature at which they begin to smoke, the smoke point, varies from fat to fat.
You must preheat your oven to a temperature past the smoke point of your chosen fat. If you don’t, and your oil buffed pan doesn’t smoke, you will not achieve the smooth hard surface you’re looking for.
What To Avoid When Seasoning A Cast Iron Pan
When done correctly, seasoning your cast iron pan will result in a smooth non-stick surface on which it is a pleasure to cook. However, there are plenty of pitfalls, so here’s a quick list of what to avoid when seasoning your cast iron pan.
Skipping The First Wash
If you do not wash your pan in warm soapy water, you risk applying your fat to a dirty surface. Even if the pan looks clean, there can be enough tiny debris to prevent your fat from polymerizing efficiently.
As a result, you may end up with a surface that has microscopic holes, preventing it from being non-stick.
Not Drying The Pan Thoroughly
Leave even the slightest hint of moisture on the surface and it will be trapped between the oil and the pan. When you bake the pan these drops of water, no matter how tiny, can prevent the oil bonding efficiently to the surface of the pan.
As a result, you’ll either be left with a surface that has tiny holes, which will cause your food to stick or a smooth surface that is not fully adhered to the pan and, in time, flakes off.
Not Buffing The Pan Thoroughly
If you do not buff your cast iron pan and leave too much fat on the surface you will prevent the polymerization process from happening efficiently. This will leave you with a slightly sticky layer on the surface of your pan.
Using A Fat High In Saturates
If you use a fat that is high in saturates, such as bacon fat, the polymerization process will not be as efficient. You may still get a hardened layer but you won’t achieve the same level of smoothness that you will with unsaturated fat.
Not Baking Past The Smoking Point
If you don’t let your fat get so hot that it smokes, you will not achieve carbonization. As a result, you’ll be left with a sticky layer on your pan.
Not building Up Multiple Layers Of Seasoning
If you give up partway through the process, you will still have a reasonable surface on which to cook. However, this will not be as hard wearing as a multi-layer surface and you’ll have to re-season your pan much sooner.
Myth Busting Cast Iron Seasoning
There is a great deal of mythology surrounding how to season a cast iron pan. Much of it is rooted in traditions that evolved before we had ready access to saturated fats or ovens with reliable temperatures.
Using the method above, you’ll create a seasoned pan that will provide a hard-wearing non-stick surface that’s a pleasure to cook with. Not only that, you don’t have to worry about all of the cast iron pan care myths either. But that’s another article entirely.