Old Oil And Seasoned Pans: A Health Risk?

Cooking oils will polymerize at high temperatures, and with enough layers of such polymers, you wind up with a thin film of plastic-like material. This process is called seasoning and is used for cast iron pans. When an oil is heated to its smoking point, it starts releasing carcinogenic fumes (free radicals). However, after a while, the fumes stop, and what remains is polymerized oil. The question remains: is it possible that those carcinogenic free radicals remain in the seasoning?

Free radicals are released during the seasoning process

The seasoning process of a cast iron pan involves coating the pan with oil and heating it in the oven at a high temperature. This process causes the oil to undergo combustion, releasing free radicals. Free radicals are highly reactive molecules that can cause oxidative damage to cells and have been linked to various health conditions.

During the seasoning process, the oil is heated to its smoke point, which is when the oil starts to break down and release fumes that contain free radicals. These free radicals can cause a chain reaction, damaging neighbouring molecules and leading to the formation of more free radicals. This process is similar to how free radicals damage cells in the body and cause ageing.

However, it's important to note that by the time the pan cools down, the free radicals will have transformed into polymers, forming a smooth, non-stick surface. While there may be concerns about the potential health effects of consuming tiny amounts of polymerised oil, it's unlikely to pose a significant risk, especially considering the body's natural antioxidant defences.

The type of oil used for seasoning can also affect the amount of free radicals released. Oils with a lower smoke point, such as olive oil, are recommended as they produce fewer free radicals compared to oils with higher smoke points. Additionally, using too much oil or heating the pan at extremely high temperatures can increase the formation of free radicals.

To minimise the release of free radicals during the seasoning process, it is advisable to use the right type and amount of oil and heat the pan within the recommended temperature range. By following these guidelines, you can effectively season your cast iron pan while reducing the potential health risks associated with free radical formation.

Free radicals can be harmful to health

Free radicals are highly reactive and unstable molecules that are made by the body naturally as a byproduct of normal metabolism. They are atoms or molecules with unpaired electrons in their outer shell, which makes them unstable. To become more stable, they take electrons from other atoms, which can cause damage to cells and DNA, leading to illness, aging, and disease.

Free radicals are linked to a range of diseases and conditions, including:

• Central nervous system diseases, such as Alzheimer's and other dementias
• Cardiovascular disease due to clogged arteries
• Autoimmune and inflammatory disorders, such as rheumatoid arthritis and cancer
• Cataracts and age-related vision decline
• Age-related changes in appearance, such as wrinkles, gray hair, hair loss, and changes in hair texture
• Genetic degenerative diseases, such as Huntington's disease or Parkinson's

Lifestyle factors can also accelerate the production of free radicals, including exposure to toxic chemicals, such as pesticides and air pollution.

While the body produces antioxidants that can neutralise free radicals, it does not produce enough. Therefore, it is important to consume a diet rich in antioxidants to help minimise the risk of oxidative stress and damage caused by free radicals. Antioxidants can be found in fruits and vegetables, such as berries, citrus fruits, carrots, soybeans, and some meat substitutes.

In summary, free radicals can be harmful to health as they can damage cells and DNA, leading to a range of diseases and conditions. While the body produces some antioxidants to neutralise free radicals, it is important to support this process by consuming a diet rich in antioxidant-containing foods.

Seasoning is a requirement for cast iron pans

The process of seasoning cast iron involves coating the pan with a thin layer of cooking oil and heating it in an oven at a high temperature. This causes the oil to polymerize, forming a plastic-like film on the surface of the pan. Over time, as more layers of polymerized oil accumulate, the pan becomes more non-stick and less prone to rusting.

There are two main methods for seasoning cast iron pans: the first is to simply cook with the pan, using fatty foods and generous amounts of butter or cooking oil. The second method involves seasoning the pan in the oven by applying a thin layer of oil and baking it at a high temperature for an hour. This process can be repeated several times to build up a stronger layer of seasoning.

It is important to note that not all oils are suitable for seasoning cast iron pans. Oils with a high smoke point, such as vegetable oil, melted shortening, or canola oil, are recommended. Additionally, it is crucial to avoid using excessive heat or scrubbing the pan with abrasive utensils, as this can remove the seasoning.

In conclusion, seasoning is essential for cast iron pans to create a non-stick surface, protect against rust, and enhance the cooking experience. By following the proper seasoning techniques and maintenance procedures, a well-seasoned cast iron pan can last for generations.

The pros and cons of cast iron pans

Pros

Cast iron pans are durable, inexpensive, and retain heat well. They can deliver non-stick properties without the use of chemicals, and are versatile, suitable for searing, sautéing, braising, and baking. They are also long-lasting, affordable, and have excellent heat retention.

Cons

Cast iron pans are poor conductors of heat, heavy, and the handles can get very hot. They require seasoning and re-seasoning, and are not suitable for cooking all types of food. They are also slow to heat up, and the rough, ridged, or notched base can damage cooking surfaces and countertops.

The verdict

Cast iron pans have been used for centuries and are a popular choice for many cooks. They offer excellent heat retention, durability, and versatility. However, they may not be suitable for everyone due to their weight and slow heating time.

How to season a cast iron pan

While there is no definitive answer to whether seasoned pans carry free radicals in old oil, some sources suggest that the oil becomes chemically indistinguishable from its original state after it has been heated past its smoke point. It is said to undergo a process called polymerization, where it forms a plastic-like substance that is no longer toxic.

Seasoning a cast iron pan is a simple process that will ensure your pan stays in top condition and performs well for years to come. Here is a step-by-step guide to seasoning your cast iron pan:

• 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 remove any residue or impurities from the manufacturing process. Dry the pan thoroughly with a towel, then place it on a stovetop flame for a minute or two to ensure all moisture is gone.
• Rub with Oil: Once your pan is clean and dry, it's time to apply a thin layer of oil. Use a neutral oil with a high smoke point, such as canola, vegetable, or flaxseed oil. Rub the oil all over the pan, including the bottom, sides, and handle, using a paper towel or lint-free cloth. Make sure to wipe away any excess oil so that the pan feels dry to the touch.
• Bake the Pan: Place the oiled pan upside down on the middle rack of a cold oven. Line a lower rack with foil to catch any oil drips. Preheat the oven to between 350-[450] degrees Fahrenheit, depending on the oil used, and bake for about an hour. This process will polymerize the oil, creating a hard, plastic-like coating.
• Cool the Pan: After an hour, turn off the oven and let the pan cool down completely inside. This step is important, as it prevents the oil from running or pooling as it cools.
• Repeat: If your pan didn't come pre-seasoned, or if the existing seasoning is worn, repeat the oiling and baking process three to four times to build up a good initial layer of seasoning.
• Maintenance: From here on out, your cast iron pan is ready for cooking! Each time you cook with oil or fat, you will be adding to the seasoning. To maintain the seasoning, simply clean your pan with hot water (and soap if needed) after each use, dry it thoroughly, and apply a light coat of vegetable oil before storing it in a dry place.

By following these steps, you will create a durable, non-stick surface on your cast iron pan that will improve its performance and longevity. Enjoy your well-seasoned pan!

Frequently asked questions