Understanding Pans: Why Bottoms Turn Black

Pans can get black on the bottom for a variety of reasons. One common cause is the polymerization of oil, which occurs when oil splatters onto the bottom of the pan during cooking and is then heated, causing it to polymerize and turn black. Another reason could be that the pan is not being cleaned properly, especially if it is a non-stick pan, as food particles and oil can burn and stick to the pan, causing black residue. Additionally, if a pan is made of aluminium, washing it in the dishwasher with certain detergents can cause it to turn grey or black due to a chemical reaction.

Pans made of aluminium washed in the dishwasher

Pans made of aluminium can become discoloured when exposed to certain chemicals and minerals. The bottom of aluminium pans can become black due to burned oil or debris, or due to exposure to harsh chemicals and high temperatures in the dishwasher.

The high heat of the dishwasher, along with the mineral content in the water and the chemicals in the detergent, can cause a reaction that blackens aluminium cookware. The forceful jets of water, harsh detergents, and clanging against other dishes can also cause discolouration, nicks, and pock marks on the surface of the pan. Therefore, it is generally recommended to hand wash aluminium cookware.

If your aluminium pans have become blackened after being washed in the dishwasher, there are several natural products that can help restore their shine. Lemon juice, cream of tartar, and vinegar are effective in removing dark stains from aluminium cookware. Simply boil a solution of water and any of these ingredients in the pan for about 10 minutes, then remove it from the heat, drain the pan, and use a steel wool soap pad soaked in warm water to remove the lifted layers of minerals.

To prevent your aluminium pans from turning black in the first place, it is important to clean them thoroughly after each use. This includes both the top and bottom of the pan, as oil splatter and burned-on debris can cause discolouration and affect the pan's cooking surface.

Additionally, when using a gas stove, ensure that your stovetop is properly matched to your fuel supply, as an incorrect air-to-gas mixture can also contribute to the formation of black soot on the bottom of your pans.

Overheating of fats and oils

Overheating fats and oils can cause a host of issues, from damaging the cookware to being harmful to health. Firstly, it's important to understand the smoke point of the oil or fat you are using. This is the temperature at which the oil begins to smoke, producing toxic compounds and bitter flavours. Exceeding the smoke point can also destroy valuable nutrients in the oil and the food being cooked.

When oil reaches its smoke point, it can cause polymerization, where the oil molecules form long chains of polymers, resulting in a black residue on the bottom of the pan. This can be difficult to clean and may require specialist cleaning products.

Additionally, overheating oils can lead to the formation of trans fatty acids (TFAs). TFAs are associated with negative health consequences, including increased risk of cardiovascular disease and insulin sensitivity issues. The formation of TFAs is influenced by the type of oil, temperature, and duration of heating. Repeated heating of the same oil, even at lower temperatures, can also lead to increased TFA formation.

To avoid these issues, it is recommended to choose the right type of oil for the cooking method and temperature. Some oils are better suited for high-heat cooking like grilling or stir-frying, while others are better for garnishes or dressings. It is also important to store oils properly, away from heat, air, and light, to prevent oxidation and rancidity.

Poor cleaning of pans

It is important to clean the entire pan, including the bottom, after each use. This can be done with a sponge, elbow grease, and a cleaning product like Bar Keepers Friend or powdered oxalic acid. These products are effective at removing any form of oxidation or polymerized oil from the pan.

In addition to proper cleaning, it is also important to ensure that the air-to-gas mixture of the range top is correct. An incorrect mixture can cause black soot to form, contributing to the blackening of the pan bottom. This is more common with certain types of gas stoves, such as propane stoves.

If the blackening is due to poor cleaning, it is likely that the burnt-on oil or debris can be removed with some effort. However, if the pan has been scratched or the coating has started to peel, it may be more difficult to restore it to its original condition. In some cases, it may be necessary to replace the pan, especially if it is no longer non-stick or has become unsafe to use due to leaching of metals into food.

To prevent the bottom of pans from turning black, it is important to clean them thoroughly after each use, paying attention to both the top and bottom surfaces. Additionally, ensuring that the stove's air-to-gas mixture is correct can help reduce the formation of black soot. Regular cleaning of the stove burners, especially the holes, can also help maintain optimal stove function and reduce the likelihood of blackening on pans.

Using gas stoves

If you're using a gas stove and your pans are getting black on the bottom, there are several potential causes. Firstly, check that your stove is clean and free from any spills, grease, or residue. A dirty stove can cause smoke and leave sooty deposits on your pans. It's important to regularly clean your stove, especially the gas burners, to prevent this. Use a damp sponge or cloth with warm soapy water, and clear any dirt or debris from the ports or openings on the burners with a needle, straight pin, or small-gauge wire.

Another potential cause is that the heat may be too high, or the flame may not be heating your pans evenly. The proper burner flame should be 5/8 inches high with a well-defined blue flame. If the flame is blue with a yellow centre, or entirely yellow, this indicates a problem with the air-gas mixture, which can be adjusted by modifying the air intake valve or air shutter. Lower the heat so that the flame is not touching the bottom of the pan, and try to cook on a lower setting for longer to avoid black marks.

Additionally, the type of cookware you use matters. Low-quality, inexpensive cookware may cause uneven heating, leading to black marks on the bottom of your pans. Investing in high-quality stainless steel or aluminum pans can help prevent this issue. Cast iron pans are also a good option, as they are already black and require less cleaning and maintenance.

Finally, you can try using a flame tamer, which is a metal plate placed over the gas burner to evenly distribute heat and prevent direct contact between the flame and your cookware, reducing the chances of soot buildup.

Pre-seasoning of pans

Pans can get black on the bottom due to the polymerization of oil. When sauteing, oil may splatter onto the bottom of the pan, and when heated, it polymerizes, forming a black coating. This can be removed with a metal brush, or cleaning products such as Bar Keepers Friend.

To prevent this from happening, pans can be pre-seasoned. Pre-seasoning is the process of creating a natural, non-stick coating on the surface of the cookware. This is done by applying a thin layer of oil and heating the pan to a specific temperature, which polymerizes the oil and forms a protective layer that prevents food from sticking. This also helps to enhance the flavour of dishes cooked in the pan and improves its durability by protecting it from rust and corrosion.

• Wash and dry your pan: Give the pan a good scrub with warm, soapy water, then dry it thoroughly. You can place the pan on a stovetop flame for a minute or two to drive off any lingering water.
• Rub it with oil: Rub the pan all over, inside and out—including the handle—with cooking oil. Oils such as vegetable, canola, and corn oil are recommended. Flaxseed oil should be avoided as it tends to flake off. Make sure to buff the oil so that the pan no longer looks greasy.
• Heat the pan in the oven: Place the oiled pan in a preheated oven at a temperature between 300 to 500 degrees Fahrenheit for 30 minutes. It may get smoky, so keep your kitchen well-ventilated. The oil will polymerize and form a hard, plastic-like coating.
• Repeat the process: Take the pan out of the oven and rub it once more with oil, buffing it out. Then put it back in the oven for another 30 minutes. Repeat this process three to four times to set a good initial layer of seasoning.
• Cool the pan: Once you have completed the above steps, let the pan cool down. Your pan is now ready for cooking!

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