The Science Of Seasoning: Unlocking The Non-Stick Power Of Cast Iron Pans

Seasoning a cast iron pan is the process of coating the surface with fat or oil, which is then heated to produce a corrosion-resistant layer of polymerized fat. This layer, known as the seasoning, is a hard, protective coating that helps to prevent food from sticking to the pan and protects the metal from rusting. The process involves coating the pan with a thin layer of oil, such as canola or vegetable oil, and then heating it in an oven at a high temperature, typically around 450-500°F (230-260°C). This process is repeated multiple times to build up a strong, non-stick coating. While modern pans often come pre-seasoned, it is important to re-season them periodically to maintain the protective layer.

Seasoning is a layer of carbonized oil

The process of seasoning a cast iron pan typically begins with cleaning the pan to remove any old seasoning, residues, or coatings. This is followed by coating the pan with a thin layer of cooking oil or fat, such as vegetable oil, canola oil, or corn oil. The pan is then heated in an oven at a temperature between 350°F and 500°F for about 30 minutes to an hour. This process may be repeated multiple times to build up a stronger layer of seasoning.

It is important to note that the seasoning process may vary slightly depending on different sources and preferences. Some people advocate for using different types of oils or fats, such as flaxseed oil, lard, or Crisco. The oven temperatures and duration of heating may also differ, with some recommending temperatures above 500°F and others suggesting lower temperatures.

By regularly cooking with a cast iron pan, you can naturally add layers of seasoning over time. Each time you cook with oil or fat, you are essentially seasoning the pan, enhancing its non-stick properties and durability. However, certain activities, such as cooking acidic foods or using excessive heat, may remove some of the seasoning. Therefore, it is recommended to occasionally re-season the pan using the oven method to maintain its optimal condition.

The process of seasoning is called polymerization

Seasoning a cast iron pan is a process that involves coating the surface of the pan with a layer of carbonized oil or fat, which is then baked on through a process called polymerization. This protective layer prevents the iron from corroding and rusting due to oxygen and moisture in the air. It also creates a natural, easy-release finish that makes cooking and cleaning easier.

Polymerization is a chemical process that occurs when oils or fats are heated at a high enough temperature. The oil or fat changes from a wet liquid into a slick, hardened surface that is molecularly bonded to the iron. This reaction creates a layer of seasoning that forms a natural, non-stick coating.

The process of polymerization can be broken down into several steps. First, the cast iron pan is thoroughly cleaned to remove any residue or coating. Then, a very thin layer of cooking oil or fat is applied to the surface of the pan. The pan is then placed in an oven and heated to a high temperature, typically between 350-500 degrees Fahrenheit. This causes the oil or fat to polymerize and form a hard, plastic-like coating. The pan is then removed from the oven and allowed to cool, with the seasoning continuing to cure and adhere to the iron.

Multiple layers of seasoning are required for the best long-term results. With each subsequent layer, the cast iron pan becomes smoother and darker, improving the seasoning and making it more durable. This process can be repeated as needed to maintain the seasoning and ensure the pan remains non-stick and protected from corrosion.

Seasoning prevents rusting

Seasoning is a layer of carbonized oil that forms a protective coating on cast iron pans. This coating is achieved through a process called polymerization, where the oil is heated at a high temperature, hardening and bonding to the iron. This protective layer prevents the iron from coming into contact with oxygen and moisture in the air, which would otherwise cause the pan to corrode and rust.

The process of seasoning a cast iron pan is simple and can be done at home. Firstly, the pan is washed and dried thoroughly to ensure no moisture remains. Then, a thin layer of cooking oil is applied to the entire surface of the pan. The pan is then placed upside down in an oven preheated to between 350 and 500 degrees Fahrenheit, with a baking sheet or aluminium foil placed on the rack below to catch any excess oil. The pan is baked for around 30 minutes to an hour, during which time the oil polymerizes and forms a hard coating. This process can be repeated a few times to build up a stronger initial layer of seasoning.

Once the initial seasoning is complete, the best way to maintain the layer is simply to use the pan regularly. Each time the pan is used with oil or fat, another layer of seasoning is added. Over time, these layers build up, creating a smoother, darker, and more non-stick cooking surface.

It is important to note that certain activities may remove or damage the seasoning, such as cooking acidic foods, using excessive heat, or scrubbing with abrasive utensils or scouring pads. Therefore, it is recommended to rub oil into the pan after each use to ensure the seasoning remains effective. Additionally, if the pan becomes rusty, it is possible to restore it by scrubbing the rusty areas, washing and drying the pan, applying a thin layer of oil, and baking it in the oven, following the same process as for initial seasoning.

How to season a cast iron pan

A cast-iron pan is a versatile tool that can withstand extreme heat and evenly cook food. Seasoning a cast-iron pan refers to the process of creating a protective layer of oil baked into the cookware's surface, which makes the equipment more durable, improves its ability to conduct heat, and prevents rust. This process is done through a method called polymerization, where thin layers of fat (like oil) are heated and bonded to the metal.

Step 1: Wash and Dry Your Pan

Start by giving your pan a good scrub with warm, soapy water. This is especially important if your pan is new, as you want to ensure any residue from manufacturing or transportation is removed. Dry the pan thoroughly with a towel or cloth, and if needed, place the pan on a stovetop flame for a minute or two to drive off any remaining water.

Step 2: Apply a Thin Layer of Oil

Using a paper towel, lint-free cloth, or silicone pastry brush, coat the pan with a thin layer of oil. Be sure to cover all surfaces, including the bottom, handle, and outside of the pan. The type of oil you use is up to you, but it is recommended to use oils with a high smoke point, such as vegetable oil, canola oil, or melted shortening. Avoid using too much oil, as this can make your pan sticky. The pan should feel practically dry to the touch.

Step 3: Bake the Pan

Place the oiled pan upside down in a cold oven, with a large baking sheet or aluminium foil on the bottom rack to catch any oil drips. Preheat the oven to between 350°F and 500°F (176°C to 260°C). Bake the pan for about an hour, then turn off the oven and let the pan cool down inside. This step may generate some smoke, so be sure to keep your kitchen well-ventilated.

Step 4: Repeat the Process

If your pan did not come pre-seasoned, you may need to repeat the oiling and baking process three to four more times to build up a good layer of seasoning before using it for cooking. Additionally, you should repeat this seasoning process whenever you notice the seasoning wearing off, which can happen due to cooking acidic foods, using very high heat, or scouring the pan.

Oils to use for seasoning

Seasoning a cast iron pan is a process that involves baking a layer of oil onto the surface of the pan, creating a protective coating that makes the pan non-stick and helps prevent rusting. This process is known as polymerization, where the oil is heated and bonded to the iron, creating a hard, blackened skin.

When it comes to choosing an oil for seasoning cast iron, there are a few factors to consider, such as smoke point, availability, affordability, and effectiveness. Here are some of the most commonly used oils for seasoning cast iron:

• Vegetable Oil: Vegetable oil is a popular choice for seasoning cast iron due to its high smoke point, making it ideal for cooking at higher temperatures. It is also affordable and readily available. Lodge, a popular cast iron cookware brand, uses a thin layer of soy-based vegetable oil for seasoning their cast iron pans.
• Canola Oil: Canola oil is another recommended option for seasoning cast iron. It has a high smoke point and is easily accessible in most grocery stores. Lodge also offers a canola oil-based seasoning spray, making it convenient for application.
• Melted Shortening: Melted shortening, such as Crisco, is a versatile and affordable option for seasoning cast iron. It has a high smoke point of 490 degrees Fahrenheit and can be found in most grocery stores.
• Avocado Oil: Avocado oil is favoured by some cast iron enthusiasts due to its high smoke point, versatility, and health benefits. Refined avocado oil has a smoke point of around 500-520 degrees Fahrenheit, making it suitable for high-temperature cooking. It is also neutral in flavour and can be used for various cooking purposes.
• Flaxseed Oil: Flaxseed oil has gained popularity for seasoning cast iron due to its ability to form a hard and slick surface. However, it has a low smoke point of 225 degrees Fahrenheit, making it prone to flaking and chipping. It is also more expensive and challenging to find.
• Grapeseed Oil: Grapeseed oil is recommended by some cast iron manufacturers for its high smoke point and effectiveness in creating a strong seasoning layer. It is also neutral in flavour, making it versatile for various cooking applications.
• Other Options: Other oils that can be used for seasoning cast iron include olive oil, sunflower oil, lard, and bacon grease. However, it is important to consider the smoke point and the potential impact on the flavour of the oil when choosing an option.

When seasoning cast iron, it is crucial to apply a thin layer of oil and ensure that the pan is heated to the oil's smoke point to achieve effective polymerization.

Frequently asked questions