Seasoning is the process of applying a layer of oil or fat to cast iron cookware, which is then heated to create a nonstick surface and protect the pan from rust. This protective layer is formed through a chemical reaction called polymerization, which occurs when the oil is heated past its smoke point.

Properly seasoned cast iron cookware enhances its nonstick properties, prevents rust, and improves the overall cooking experience. A well-seasoned pan can last for generations, making it a valuable kitchen investment.

The smoke point of an oil is the temperature at which it begins to smoke and break down. For effective seasoning, it's crucial to use an oil with a high smoke point, as this allows the oil to bond to the cast iron without burning.

Olive Oil:

Light/Refined Olive Oil: Approximately 465°F
Extra Virgin Olive Oil: Approximately 325°F to 375°F

Vegetable Oil:

Typically ranges from 400°F to 450°F, depending on the specific type.

Given these smoke points, vegetable oil generally offers a higher tolerance to heat compared to extra virgin olive oil, making it a more suitable choice for seasoning cast iron.

Availability: Olive oil is commonly found in most kitchens, making it a convenient option for many cooks.
Flavor: Extra virgin olive oil can impart a subtle flavor to dishes, which some may prefer.

Lower Smoke Point: The lower smoke point of extra virgin olive oil can lead to it breaking down at high temperatures, resulting in a less effective seasoning layer.
Potential Rancidity: If not used frequently, olive oil can turn rancid, especially in the presence of heat and air.

Higher Smoke Point: With a smoke point around 400°F to 450°F, vegetable oil is better suited for seasoning cast iron at high temperatures.
Cost-Effective: Vegetable oil is generally more affordable than olive oil, making it a practical choice for regular use.
Neutral Flavor: The neutral flavor of vegetable oil means it won't alter the taste of your food.

Less Flavor: While its neutrality can be an advantage, some cooks may prefer the flavor profile that olive oil provides.

Based on the smoke points and properties discussed, here are some recommended oils for seasoning cast iron:

Vegetable Oil: A versatile option with a high smoke point, making it ideal for seasoning.
Canola Oil: Similar to vegetable oil, it has a high smoke point and is often recommended by manufacturers like Lodge.
Avocado Oil: With a smoke point of 500°F, it's an excellent choice for high-heat cooking and seasoning.
Light/Refined Olive Oil: If you prefer olive oil, opt for the refined version to ensure a higher smoke point.

Certain oils should be avoided for seasoning cast iron due to their low smoke points and high concentrations of saturated fats, such as coconut oil, butter, and lard. These can lead to ineffective seasoning and may even cause your cookware to rust.

When choosing between olive oil and vegetable oil for seasoning cast iron, vegetable oil emerges as the better option due to its higher smoke point, affordability, and neutral flavor. While olive oil can be used in a pinch, especially if it's light or refined, it may not provide the same level of protection and performance as vegetable oil. Ultimately, the choice of oil will depend on personal preference, but for optimal results, consider using vegetable oil or other high-smoke-point oils like avocado oil for your cast iron cookware.