6 Stains on Stainless Steel

Stains on Stainless Steel….

And how to remove them!

Struggling with stains on stainless steel cookware? You’re not alone.

While it may seem contradictory, it is important to note that stainless steel, despite being a resilient and long-lasting material for cookware, is still susceptible to staining. To effectively clean a stainless steel pan, the initial step is to determine the nature of the stain. Is it caused by burnt food, does it exhibit a rainbow-like coloration, or is it showing signs of pitting?

Rest assured, I am here to assist you! Below, you will find the six most frequently encountered stains on stainless steel and the appropriate methods to eliminate them.

Stains on Stainless Steel Cookware #1

White Stains aka Water Stains aka Calcium Deposits

These stubborn white stains seem impossible to remove. It turns out that these stains are actually calcium deposits.

You might be wondering how calcium ended up on your pans. Well, even if your tap water is not considered hard water, it still contains traces of calcium bicarbonate. When this water is heated or used for cooking, the bicarbonate breaks down into calcium carbonate, also known as chalk or limescale. This is the white substance that sticks to the bottom of your pans. Take a look at one of my pans with this familiar hazy residue.

Unfortunately, calcium carbonate does not easily dissolve in water, which is why regular soap and water cannot remove these deposits. Additionally, it is not soluble in oil, so even cooking with oil in the pan won't get rid of it.

Are the white deposits on stainless steel harmful?

No, it is a typical and benign accumulation on your pans. Apart from causing discoloration and affecting the appearance, it does not pose any significant concerns.

How to remove white calcium deposits on your stainless steel pans?

To remove calcium deposits from your stainless steel pan, you can dissolve them using an acidic solution such as a mixture of water and vinegar or a mild oxalic acid product like Bar Keepers Friend. In my experience, I heated a combination of ⅓ cup water and ⅓ cup white vinegar (#ad) in the pan for a few minutes, then rinsed and wiped it clean. The result was a shiny pan without any white haze.

Stains on Stainless Steel Cookware #2

Pitting

Recently, my husband unintentionally left a stainless steel saucepan on the stove for an extended period of time, causing all the water to evaporate completely. Unfortunately, this led to the formation of numerous small discolored dots on the bottom of the pan, which have proven to be quite stubborn to remove. As a result, we now possess a pan with a pitted surface.

What is pitting?

Pitting is not a stain, but rather a form of erosion that occurs on the surface of metal. In the case of stainless steel, pitting is caused by the presence of chlorides, such as salt. This is why the tap water that was boiled in our pot, which had some salt dissolved in it, resulted in pitting once all the water had evaporated.

For those who are interested in a more scientific explanation, the reason why stainless steel is resistant to corrosion is due to the presence of chromium. When chromium reacts with oxygen in the air, it forms a thin layer of chromium oxide on the surface of the steel. This layer of chromium oxide is what makes stainless steel passive and protects it from rusting.

While boiling salted water for cooking purposes typically does not damage stainless steel, adding undissolved salt to a stainless steel pot or boiling water dry can cause the chloride in the salt to attack the passive layer of chromium oxide, resulting in pockmarks where the oxide has been removed.

Can you remove pitting stains?

Based on information from hunker.com, it is indeed possible to remove pitted and/or rusted parts from a stainless steel pan by grinding them out and taking precautions to prevent future damage. This includes avoiding prolonged exposure to substances like salty water or vinegar. However, for those who are unwilling or unable to go through the process of grinding the pan, the answer would be no. Once a stainless steel pan is pitted, it remains pitted.

Is it safe to use a pitted pan?

If you have read my previous article on stainless steel cookware or have conducted any research on the topic, you would be aware that it does release small amounts of nickel and chromium into food. For most individuals, these quantities are not significant, and stainless steel is generally considered a safe material for cookware.

According to most sources, a pan with pits is still safe to use and will not lose its functionality, although its appearance may be compromised. The chromium in the stainless steel would have already formed a new layer of chromium oxide over the pits, making the pot just as resistant to corrosion as before.

However, some individuals caution that a heavily scratched and pitted pot may release higher amounts of these metals, and it is advisable to dispose of them. Personally, I have decided to discard my pitted stainless steel saucepan and purchase a new one (#ad). I prefer not to take any chances.

Ultimately, the decision is yours to make.

Stains on Stainless Steel Cookware #3

Rust

Indeed, it is true that stainless steel, by its inherent properties, is resistant to corrosion. However, it is not entirely immune to corrosion and can occasionally develop rust. If you are curious about the factors that can cause stainless steel to rust, I have addressed this topic in detail in my article.

There are two inquiries that often arise:

1. How can one effectively eliminate rust spots from stainless steel pans?
2. Is it safe to use a pan that has developed rust?

How to remove rust spots from stainless steel pans

It is important to avoid using steel wool, hard metal brushes, or abrasive cleaners on your stainless steel pan if you notice a bit of rust. These can actually make the pan more prone to corrosion. Instead, there are a couple of alternative options you can consider. One option is to create a thick paste using baking soda and water, and then apply it to the rusted areas. You can use a toothbrush, plastic scrubby, or soft cloth to gently rub the mixture onto the rust, and it should come off easily. Another effective option is to use Bar Keepers Friend, which works just as effectively.

Is a rusty pan safe to use?

Having said that, you don’t want to be consuming large amounts of it, so make sure you follow the above steps to make sure the rust has been cleaned off the pan before you use it again.

Personally, however, I would avoid using a pan that shows signs of rusting. In my opinion, a pan once rusted is always going to be susceptible to rusting again, even if you remove all the corrosion. Also, I prefer to play it safe. In this article at prevention.com, toxicologist James H. Woods, PhD, of the department of environmental and occupational health sciences at University of Washington says that while he is not aware of any health issues related to eating food made in rusted pans, why would you take the risk? He recommends buying new cookware

So do I.

Stains on Stainless Steel Cookware #4

Heat Tint

In case you are acquainted with heat tint, it refers to the unsightly rainbow-colored staining on your stainless steel pan that occurs due to excessive heat or rapid heating. It does not impact the pan's functionality or the quality of the food cooked in it, only its appearance. To be frank, the majority of my stainless steel cookware appears to be heat tinted, and it has never really bothered me.

What exactly causes heat tint?

Stainless steel is a metal alloy composed of iron, carbon, chromium, and nickel. The chromium in the steel reacts with oxygen in the air to create a thin layer of chromium oxide, which acts as a barrier to prevent further reactions with the metal. 

However, when stainless steel is heated, the oxidation process intensifies, causing the top layer to thicken. This thickening layer alters the wavelength of light that it reflects, resulting in a range of colors. As the temperature continues to rise, the oxidation process increases, causing the colors to shift from yellowish to blue.

How to remove heat tint?

Bar Keepers Friend is a versatile cleaning product that can be effectively used to clean a Stainless Steel pan. Whether it's removing heat tint or giving your pan some tender loving care, a small amount of BFK will do the trick. Another option is to create a mixture of white vinegar and water, which also works exceptionally well.

Stains on Stainless Steel Cookware #5

Burnt Food

This particular stain is not my favorite, but it's one that I have the most experience with. In my opinion, it's also the most challenging to remove from a stainless steel pan. If you've ever been tempted to throw out a pan with stubborn burnt-on food, you're not alone. I must confess that I may have done so in the past.

However, the more important question is how to clean burnt stainless steel cookware. I've found that baking soda is quite effective. Simply cover the base of the pot with water and sprinkle generously with baking soda. Let it sit for at least 30 minutes, then gently scrub with a plastic scrubber. For tougher burns, leave it in for longer.

Another option is Bar Keepers Friend. Check out this amazing video that demonstrates how well this cleaner works for removing scorch stains from a pan. Although the pan in the video is enamel, the principle remains the same.

Stains on Stainless Steel Cookware #6

Black or Grey Residue on New Stainless Steel Cookware

This particular situation is quite unusual and not something I have personally encountered. However, I have come across numerous inquiries regarding the best method to clean a stainless steel pan that has a black or grey residue. This prompted me to conduct further research on the matter.

Based on the experiences shared by several users, the following pattern has emerged: Upon purchasing a new set of stainless steel cookware, individuals typically follow the expected procedure of washing it with warm soapy water before its initial use. So far, everything seems to be in order. However, when it comes time to wipe the inside of the pan, they discover that a black or grey residue is being transferred onto the paper towel.

What makes this situation intriguing is that the residue remains even after multiple washes and cleaning attempts.

What is the black residue on new stainless steel cookware?

SS cookware undergoes a mechanical polishing procedure that employs extremely fine abrasives to achieve a glossy finish. However, there are instances when this method results in a stubborn residue that cannot be eliminated through manual or dishwashing means.

How to clean a stainless steel pan that has black residue?

KitchenAid suggests the following method: apply a small quantity of olive oil onto the interior of the pan. Allow it to sit for a while and then remove the oil by wiping it off. Subsequently, proceed to clean the pan with dish soap and hot water.

Alternatively, you can try gently scrubbing the pan using a combination of lemon juice and salt, followed by washing.

For certain stainless steel cookware, it is recommended to gently scrub it with a mixture of baking soda and warm water in a 1:1 ratio before using the pans.

Some final words of caution:

Here are some important reminders to keep in mind when it comes to maintaining your stainless steel cookware:

1. Avoid using oven cleaner on your cookware as it can cause abrasion.
2. Stay away from chlorine-based cleaners such as Comet and Ajax, as they can corrode stainless steel. Instead, opt for acid-based cleaners like Bar Keepers Friend or plain white vinegar.
3. Do not bleach your cookware with chlorine bleach.
4. Refrain from using abrasive steel wool, as it can remove the protective layer of chromium oxide and leave your pan vulnerable to corrosion and rust. Instead, use a plastic scrubby.
5. When adding salt to boiling water, make sure to bring the water to a rolling boil before adding salt and stir well. This will help prevent the pan from developing pits.

By following these precautions, you can ensure the longevity and quality of your stainless steel cookware.