Cast Iron Seasoning: A Step-By-Step Guide

Seasoning cast iron pans is a crucial step in maintaining their non-stick properties and preventing rust. It involves creating a natural, non-stick coating on the surface of the cookware by applying a thin layer of oil and heating the pan to a specific temperature. This process, called polymerization, transforms the oil into a plastic that bonds to the pan, sealing the porous surface of the cast iron and creating a protective layer.

Cleaning cast iron pots and pans before seasoning

To clean cast iron pots and pans before seasoning, you'll need to follow a few simple steps. Firstly, wash the cookware with warm or hot water and a small amount of mild dish soap. You can use a non-abrasive sponge, scrub brush, or pan scraper to gently scrub the surface. If there is stuck-on food, you can add a little kosher salt and a few drops of warm water to help loosen it. Rinse the cookware thoroughly to remove any soap residue.

Once the cookware is washed, it's important to dry it completely. You can use a lint-free cloth, paper towel, or even place it in a low-heat oven or stove to ensure all moisture is removed. This step is crucial as any remaining moisture can cause rusting.

After drying, apply a thin layer of cooking oil or seasoning spray to the surface of the cookware. Use a paper towel to wipe the oil until no residue remains. This step helps protect the surface and prepares it for the seasoning process.

If your cast iron cookware has rust spots, you may need to take additional steps before seasoning. Use steel wool or a rust eraser to remove the rust, then rinse and dry the cookware. Apply a thin layer of cooking oil and place the cookware in an oven, upside down, at 450-500 degrees Fahrenheit for about an hour. Allow it to cool, and repeat the process if necessary until the rust is gone.

By following these steps, your cast iron pots and pans will be clean and ready for seasoning.

Applying a thin layer of oil

To season cast iron pans, you need to apply a thin layer of oil and heat the pan to a specific temperature. This process, called polymerization, transforms the oil into a plastic that bonds to the pan. The plastic coating seals the porous surface of the cast iron, preventing excessive sticking during cooking, as well as warding off rust.

Step 1: Wash and Dry Your Pan

Give the pan a good scrub with warm, soapy water, then dry it thoroughly. Even after towel-drying, some surface moisture may remain, so it's best to put the pan on a stovetop flame for a minute or two to drive off any lingering water.

Step 2: Apply a Thin Layer of Oil

Using a paper towel, coat the pan with a thin layer of oil, including the bottom and handle of the pan. Wipe away all excess oil so no pooling oil is visible — the oil should just coat the metal. The pan should feel practically dry to the touch. Using too much oil will cause your pan to become sticky.

Step 3: Buff the Pan

Keep rubbing and buffing the oil into the pan until it no longer looks greasy. Avoid using too much oil, as this will result in a sticky, grimy finish. If you slide your finger across the pan and it looks like you just ate delicious fried chicken and French fries, that's too much oil! Keep buffing!

Step 4: Choose the Right Oil

The type of oil you use is important. Avoid using butter or unrefined coconut oil because trace amounts of dairy solids and pulp will burn and scorch. Traditional lard will turn rancid faster without frequent use. It is recommended to use unsaturated oils that are neutral in flavor with a smoke point of around 400°F: canola, vegetable, grapeseed, sunflower, and safflower are all great options. Some cooks also recommend flaxseed oil, but due to its very low smoke point, it will make your kitchen very hazy and smoky.

Step 5: Preheat the Oven and Bake the Pan

Preheat your oven to at least 450°F, then slide your pan into the oven. The goal here is to heat the oil past its smoking point to trigger polymerization, which bonds the oil to the pan. Bake the pan for 45 minutes to 1 hour, then turn off the oven and let the pan remain inside for another 15 minutes. Carefully remove the pan with thick oven mitts and let it cool completely.

Step 6: Repeat the Process

To secure the seasoning, you can repeat the oiling and baking process again to create a more solid layer of protection. Some cooks like to repeat this process up to 6 times. However, note that each time you use your cast-iron pan, you will likely be cooking with some sort of oil or fat, which becomes a mini-seasoning process. Over time, through proper use and maintenance, the seasoning on your pan will become stronger organically.

Heating the pan to a specific temperature

When heating the pan, it is recommended to place it upside down in the oven with a baking sheet or aluminium foil on the bottom rack to catch any excess oil that drips off. The pan should be heated for around 30 minutes to an hour, depending on the material of the pan. For cast iron pans, the recommended temperature is 450 degrees Fahrenheit, and the pan should be left in the oven for about 45 minutes to an hour.

The reason for using the oven instead of the stovetop is that it provides more even heat distribution, resulting in a more uniform seasoning. However, seasoning on the stovetop is possible for some pan materials, such as carbon steel. When using the stovetop method, gradually heat the pan over medium heat and add the oil once the pan is warm. Continue heating until the oil starts to smoke slightly, indicating that it is polymerizing and creating a protective layer.

After heating, the pan should be allowed to cool completely before removing any excess oil with a clean cloth or paper towel. Repeating the oiling and heating process multiple times will result in a stronger seasoning layer.

Baking the pan in the oven

To season cast iron pans, you need to bake a thin layer of oil onto the pan through a process called polymerization. This gives the cookware a classic black patina and a natural, easy-release cooking surface. It also helps to prevent rust.

Step 1: Preheat the oven

Preheat your oven to 400 degrees Fahrenheit. If you are seasoning multiple pans at once, you can preheat to a higher temperature, typically ranging from 300 to 500 degrees Fahrenheit.

Step 2: Clean and dry the pan

If your pan is new, give it a good scrub with warm, soapy water. Rinse and hand dry it thoroughly. Even after towel-drying, some surface moisture may remain, so it is recommended to place the pan on a stovetop flame for a minute or two to drive off any lingering water.

Step 3: Apply a thin layer of oil

Once your pan is clean and dry, apply a thin layer of vegetable oil, canola oil, or flaxseed oil to the entire surface of the pan, including the bottom. You may exclude the handle in most cases. Make sure to coat all areas of the pan except the handle. You can use a paper towel or a brush to apply the oil.

Step 4: Prepare the oven

Line a baking sheet with aluminum foil and place it on the oven's bottom rack to catch any drippings.

Step 5: Place the pan in the oven

Place the coated cast iron pan on the middle rack of the preheated oven. You may choose to place the pan upside down to allow excess oil to drip off during the seasoning process.

Step 6: Bake the pan

Bake the pan for 45 minutes to an hour. The oil will polymerize and form a protective layer that prevents food from sticking. This gradual cooling process helps the oil to polymerize and creates a durable non-stick coating on the surface of the pan.

Step 7: Cool the pan

After the designated time has passed, turn off the oven and allow the pan to cool completely.

Step 8: Remove the pan and wipe it down

Once the pan has cooled, remove it from the oven and wipe it down with a clean cloth to remove any excess oil residue. Your pan is now seasoned and ready for use!

Additional tips:

• Repeat the process for an unseasoned or stripped pan: If you are starting seasoning from scratch, repeat the above steps multiple times until a smooth finish develops.
• Avoid using too much oil: Using too much oil will cause your pan to become sticky. The pan should feel practically dry to the touch.
• Re-season as needed: Seasoning cast iron pans is a crucial step in maintaining their non-stick properties and preventing rust. Over time, the seasoning erodes, and you will need to re-apply it. You'll know the seasoning has eroded when the surface looks dry and patchy in spots.

Repeating the process for an unseasoned or stripped pan

If you're starting from scratch with an unseasoned or stripped pan, you'll need to repeat the seasoning process multiple times until a smooth finish develops. It's important to resist the urge to slather on a lot of oil, as this will only make the pan sticky. Good seasoning is built up from many thin layers.

First, using a paper towel, coat the pan with a neutral oil like canola or vegetable oil (including the bottom and handle of the pan). Wipe away all excess oil so no pooling oil is visible — the oil should just coat the metal. The pan should feel practically dry to the touch.

Then, bake the pan for 1 hour at 350°F. It's important to bake the pan upside down and to line the rack below with foil to catch any oil drips. This will protect the surface and give it an almost non-stick quality.

After an hour, turn off the oven and let the pan cool in the oven before touching it.

Repeat these steps for an unseasoned or stripped pan.

Frequently asked questions