Stainless Steel Pans: Why Do They Turn Black?

Stainless steel is a durable, non-toxic metal that is resistant to corrosion and acids. However, it can still stain under certain circumstances. Stainless steel is an iron-based metal that is alloyed with chromium and sometimes nickel. The iron in stainless steel can make it susceptible to stains if it is exposed to high levels of pressure, heat, or moisture.

Stainless steel can develop black carbon residue, especially on the bottom of pots, when placed directly on a burner. This can be removed with baking soda and a nylon-bristled brush.

Stainless steel can also develop rainbow stains due to overheating. This is caused by a thin protective layer of chromium oxide that changes colour when combined with air and high heat. This can be removed with vinegar and a non-abrasive sponge.

Stains from burnt food

Burnt food on stainless steel pans can be a challenge to clean, but it is possible. Here are some methods to tackle these stubborn stains:

Baking Soda and Vinegar

Combine equal parts water and vinegar in the pan and bring the mixture to a boil. Turn off the heat and add two tablespoons of baking soda. Discard the liquid and wash the pan with a scouring pad. For stubborn residue, make a paste with more baking soda and water, apply it to the affected area, and let it sit for a few minutes before scrubbing again.

Dishwasher Tablet

Cover the burnt area of the pan with a small amount of water and warm it over low heat. Remove from the heat and use the tablet to scrub the burnt-on bits. Rinse and wash the pan with warm soapy water.

Boiled Lemons

Cut two or three lemons into quarters and place them in the pan. Add enough water to cover the lemons and bring it to a boil. Continue boiling for 5-10 minutes or until food particles start to float to the surface. Discard the lemons and water, then rinse and scrub the pan with a scouring pad to remove any remaining residue.

Aluminium Foil and Baking Soda

Cover the burnt area with two to three tablespoons of baking soda and add a small amount of water to create a paste. Crumple up a piece of aluminium foil and use it to scrub the paste all over the burnt area until the food bits and stains are gone. Rinse the pan with warm soapy water.

Bar Keeper's Friend

Bar Keeper's Friend is a popular choice for cleaning stainless steel. It is a multi-purpose cleaning powder that uses oxalic acid to dissolve tough stains like rust and calcium deposits. The powder also has a mild abrasive quality to help scrub away burnt-on food. Sprinkle the powder on the affected area, add a small amount of water, and scrub with a sponge or scouring pad.

Salt

Sprinkle coarse salt over the burnt areas and let it sit for about five minutes. Then, scrub the area with a rough sponge or scouring pad. The salt will act as an abrasive to help lift the burnt-on food.

Water stains

Identification:

Firstly, it's essential to identify the type of stain you're dealing with. Water stains on stainless steel pans often appear as white or hazy residue that doesn't scrub away easily. These stains are typically caused by the presence of calcium in tap water.

Removal:

To remove water stains from your stainless steel pans, follow these steps:

• Create a mixture: Combine equal parts water and white vinegar in your pan, aiming for about 1/3 cup of each liquid.
• Warm the mixture: Place the pan on the stove and warm the mixture for a few minutes. This step helps dissolve the calcium deposits.
• Discard and wash: After warming, carefully discard the liquid. Then, proceed to wash the pan with mild soap and water as usual.
• Wipe and inspect: Dry the pan with a clean cloth or towel and inspect the results. If the water stains are particularly stubborn, you may need to repeat this process.

Prevention:

To prevent water stains from reappearing, consider the following tips:

• Dry promptly: Always dry your stainless steel pans promptly after washing. Water spots are more likely to form if the pans are left to air-dry.
• Add salt after boiling: When cooking pasta or dishes that require boiling water, it's best to bring the water to a rolling boil before adding salt. This simple step can help prevent pitting corrosion, which causes small dents in the bottom of your pan.
• Avoid harsh chemicals: Steer clear of harsh chemicals like bleach or oven cleaner when cleaning your stainless steel pans. These can damage the protective layer on the pan's surface and make it more susceptible to staining and corrosion.

Remember, while water stains on your stainless steel pans may be unsightly, they are typically harmless. The provided instructions should help you effectively remove and prevent these stains, restoring your pans to their shiny glory!

Pitting

To prevent pitting, only add salt to water once it's already come to a boil. That way, the salt dissolves in the hot water and does not sink down to the pan's surface, thus preventing the reaction from occurring.

Once pitting starts, it cannot be reversed or removed. However, it does not affect the performance of the cookware.

Rust

Stainless steel is a sturdy metal that is resistant to rusting or corroding. However, it is not entirely rust-proof. Stainless steel pans can develop rust spots due to several factors, and it is important to address these issues to maintain the pan's durability and aesthetics. Here are some common causes of rust on stainless steel pans and detailed instructions on how to address them:

Cause 1: Salt and Moisture

Salt and moisture are primary culprits of rust on stainless steel. When salty water is left to dry on a pan, or when a pan is boiled dry with salt water, the salt can attack the protective layer of chromium oxide, making the pan susceptible to rusting. To prevent this, always ensure you wash your pan promptly after use, especially if you have been boiling salted water.

Cause 2: Acidic Environment

Acidic environments can also cause stainless steel to rust. This includes exposure to acidic foods or cleaning agents like bleach or tough abrasive solutions. When using stainless steel pans, avoid leaving acidic substances on the surface for extended periods.

Cause 3: Quality of Stainless Steel

The quality of stainless steel can also play a role in its resistance to rust. Lower-quality stainless steel with insufficient chromium content is more prone to rusting. The 200 series, for example, uses manganese instead of nickel and is less corrosion-resistant.

Removing Rust from Stainless Steel Pans:

If you notice rust spots on your stainless steel pans, here is a detailed guide on removing them:

• Rinse the pan with water.
• Cover the pan with baking soda, ensuring all rust spots are coated.
• Let the baking soda sit for an hour or more.
• Use a scouring pad or a soft cloth to gently rub the rust off. Avoid using steel wool or metal brushes as they can damage the pan further.
• Wash the pan with soap and water, then dry it completely with a clean cloth or towel.

Alternatively, you can use vinegar to remove rust:

• Spray or wet the pan with water and wipe it clean with a cloth.
• Create a 1:1 mixture of water and vinegar and spray it onto the pan.
• Let the vinegar mixture sit for a few minutes to soak into the metal.
• Using a scouring pad, lightly scrub along the grain of the stainless steel to remove the rust.
• Wash the pan with soap and water, then thoroughly dry it.

Preventing Future Rust:

To prevent rust from forming or reoccurring, follow these tips:

• Always wash and dry your pans promptly after use, especially if they have been in contact with salt or acidic substances.
• Avoid using harsh chemicals or abrasive cleaning tools that can strip away the protective chromium oxide layer.
• Opt for higher-quality stainless steel with sufficient chromium content, such as 304 or 316 stainless steel.

Heat tint

To remove heat tint, you can use a diluted solution of white vinegar and scrub the pan with a non-abrasive sponge. The acidity of the vinegar will break down the oxidized layer, restoring the pan's original colour. Alternatively, you can use a specialised stainless steel cleaner, such as Bar Keeper's Friend or Make It Like New by Made In Cookware.

It is important to note that while heat tint can be removed, it may reoccur if the pan is exposed to high heat again. Therefore, it is recommended to avoid frequent high-temperature cooking with stainless steel pans to prevent heat tint from forming.

Frequently asked questions