Stainless Steel Pans: Discoloration Normal?

Stainless steel pans are a kitchen essential, but they can be a pain to keep looking pristine. It's normal for stainless steel pans to discolour, and there are several reasons why this might happen. One of the most common causes is overheating, which can lead to stubborn burnt-on bits and discolouration. Another reason is the presence of chlorides, like salt, which can cause pitting—an erosion of the surface of the metal. Even something as simple as tap water can cause white calcium stains on your pans. Luckily, there are ways to remove these stains and restore your pans to their former glory.

Why stainless steel pans discolour

Stainless steel pans are prone to discolouration due to several factors, including high temperatures, pitting, calcium carbonate deposits, and burnt food. Here are some common causes of discolouration in stainless steel pans:

Rainbow Discolouration

The rainbow discolouration is an ugly rainbow pattern that develops on the pan due to excessive heat. Rapid heating can lead to the thickening of the steel's oxidised layer, resulting in a bluish or rainbow tint. This type of discolouration is common when using stainless steel pans frequently and can be easily removed with white vinegar and water.

Pitting or Discolouration Dots

Pitting or discolouration dots are small grey marks that appear on the pan after boiling salted water, especially when boiling starchy foods like potatoes, rice, or pasta. These dots are caused by the chloride's effect on the oxidised layer of stainless steel. While pitting doesn't impact food quality, excessive pitting can leach metal into the food, making the pans unsafe.

White Residue or Stains

White stains on stainless steel pans are typically caused by calcium deposits. Tap water often contains calcium bicarbonate, which can break down into calcium carbonate when boiled. These hazy white dots stick to the bottom of the pan and are insoluble in water, requiring an acidic medium like vinegar to remove them.

Caramel-Brown Stains

Caramel-brown stains are the result of overheating oil or fat, which burns onto the pan's surface. This discolouration can also occur when cooking without pre-heating or oiling the pan. To remove these stains, a mixture of vinegar and baking soda or salt is recommended.

Black Residue

Black residue on stainless steel pans may be leftover from the manufacturing process, known as the "polishing" procedure. This type of discolouration can be removed with baking soda or a specialised stainless steel cleaner.

To prevent discolouration, it is recommended to avoid harsh chemicals, overheating, and frequent use of cooking sprays. Proper cleaning and maintenance can help maintain the shine and performance of stainless steel pans.

How to remove white residue from stainless steel pans

Discolouration and residue are common issues with stainless steel pans, but they can be easily fixed.

Firstly, it's important to identify the type of stain. In this case, we are dealing with white residue, which is usually caused by water stains or calcium deposits.

Using Vinegar and Water

Combine equal parts vinegar and water in the pan and bring the mixture to a boil. Let it cool, then wash the pan with soap and water. You can also try using a 1:3 vinegar to water solution for lighter residue. If the residue is more stubborn, you can try discarding the first solution, making a new one, and boiling it again before cleaning the pan. You can also leave the solution in the pan overnight before cleaning.

Using Baking Soda and Lemon

Sprinkle baking soda on the bottom of the pan and scrub with the cut side of a lemon. Then, switch to a scrubby sponge and scrub the pan with hot, soapy water.

Using Bar Keepers Friend

Bar Keepers Friend is a mild oxalic acid that will dissolve away calcium deposits. Combine 1/3 cup of water and 1/3 cup of vinegar in the pan and warm the mixture for a few minutes. Then, discard the liquid and wash and wipe the pan.

Using Olive Oil

Spread a small amount of olive oil on the inside of the pan and let it sit. Then, wipe out the oil and wash the pan with dish soap and hot water.

Using Lemon Juice and Salt

Gently scrub the pan with a mixture of lemon juice and salt, then wash it with hot water.

Using Steel Wool

This method is not recommended for soft metals and delicate surfaces but can be effective for stainless steel. Wet the steel wool with water and scrub the pan.

Preventing White Residue

To prevent white residue from building up, remember to always dry your cookware immediately after washing. Also, remember to let the pan cool down before cleaning and avoid using abrasive tools like steel wool or harsh cleaners like bleach or oven cleaner, as these can damage the surface of the pan.

How to remove caramel-brown stains from stainless steel pans

It is normal for stainless steel pans to discolour over time. While stainless steel is touted as being non-corrosive, without proper cleaning and care, it can become pitted or rusted. Discolouration is often caused by overheating.

Using Vinegar

Wash your pan with vinegar and rinse with water to remove discolouration. Vinegar can also be used to remove white calcium build-up stains. Make a mixture of one part vinegar to three parts water and boil in the affected pot or pan. Allow the mixture to cool, empty the pan, and wash as normal.

Using Baking Soda and Lemon

Wet the bottom of the pan, sprinkle generously with baking soda, then scrub with the cut side of a lemon. After a while, switch to a scrubby sponge. The combination of baking soda and lemon should fizz up and help dissolve stains, while the abrasive powder will help scrub them off.

Using Bar Keepers Friend Cookware Cleanser & Polish

Bar Keepers Friend is a powdered cleaner that can scrub off stains without damaging pans. It is more effective at scrubbing the toughest stains than other methods, but it is not meant to sit on a pan for extended periods.

Using Steel Wool

Steel wool is cheap and can be moulded, so it is easy to fit into crevices. It can be reused many times and is very effective at powering through stains. However, it can leave scratches on soft metals and delicate surfaces, so it is best to only use it on stainless steel.

Using Boiling Water

Boiling water can be used to remove burnt food from stainless steel pans. Begin by scrubbing away as much food as possible with a non-abrasive scrubber. Then fill the pot or pan with water and a bit of dish soap, ensuring the stuck-on food is completely submerged. Bring the water to a boil and let it simmer for a few minutes. Remove from heat and let it cool before scraping away the loosened food with a spatula.

Using Tomato Sauce

Fill the pot or pan with tomato sauce or crushed tomatoes until the affected areas are completely submerged. Allow the sauce to simmer gently for about 10 minutes, adding water if necessary. Remove the sauce and rinse the pan clean. You can also leave the tomato sauce in the pan overnight without simmering.

How to remove rainbow stains from stainless steel pans

It is normal for stainless steel pans to discolour due to heat. This discolouration is caused by a combination of chromium (found in stainless steel) and oxygen, which creates a thin protective layer that changes colour when exposed to high heat. While this discolouration is harmless, it can be unsightly.

Step 1: Prepare the Vinegar Solution

Dilute some white vinegar with water. The vinegar solution will help to break down the oxidized rainbow layer on your pan.

Step 2: Apply the Vinegar Solution

Pour the diluted vinegar into your pan and use a soft or non-abrasive sponge to work the solution into the stained areas. You can also use Bar Keeper's Friend or a similar product as an alternative to vinegar.

Step 3: Rinse and Dry

Rinse the pan with water to remove the vinegar solution and any remaining stains. Dry the pan thoroughly with a microfiber towel or a regular dish towel.

Your pan should now be stain-free and looking brand new!

Additional Tips:

• If you want to remove burnt food or discolouration from your stainless steel pan, avoid using cold water as it can cause warping. Instead, allow the pan to cool down before cleaning it with warm, soapy water and a non-abrasive scrubber.
• To prevent scorch marks, ensure there is enough fat or liquid in the pan and that the pan is heated to a low to medium temperature before adding any food.
• For tough stains, you can try using baking soda and lemon, or steel wool with Bar Keeper's Friend Cookware Cleanser & Polish.

How to prevent stainless steel pans from discolouring

Stainless steel pans are durable, excellent heat conductors, and versatile, making them a kitchen essential. However, they are susceptible to discolouration, which is often caused by overheating. While these discolourations are harmless, they may be unsightly. Here are some ways to prevent stainless steel pans from discolouring:

Preventing Scorching and Scorch Marks

Scorch marks are often caused when there is insufficient fat or liquid in the pan, or when the pan is not hot enough before adding liquid. To prevent scorching, ensure that there is enough fat or liquid in the pan, and heat the pan on low to medium heat for two to three minutes before adding oil, fat, or food. Additionally, keep the food moving frequently with a spoon or tongs to prevent it from sitting at the bottom of the pan and burning.

Cleaning and Maintenance

Proper cleaning and maintenance of your stainless steel pans can help prevent discolouration. Always allow the pan to cool down before cleaning, as immersing a hot pan in cold water can cause warping. Rinse off excess food with warm water, then soak the pan in warm, soapy water. Wash with a non-abrasive scrubber and warm, soapy water, and wipe dry immediately with a microfiber cloth to prevent water spots.

For burnt-on food, sprinkle the surface of the pan with baking soda, then fill the pan with enough water to cover the stuck-on food. Bring it to a boil, and use a spatula or wooden spoon to scrape away the residue. Allow the pan to cool, then wash as usual.

To remove discolouration, pour some vinegar into the pan and wipe it with a non-abrasive scrubber. Rinse and dry the pan thoroughly.

Hard water can also cause white, cloudy residue on your pans. To remove this, boil a mixture of one part vinegar to three parts water, then let it cool and wash with soap and water.

To prevent water spots, be sure to dry your cookware immediately after washing. Additionally, use cookware protectors when stacking your pans to avoid scratches.

Frequently asked questions