Stainless Steel Discoloration: Why, Prevention, Fix

There is a general misconception that stainless steel does not rust, tarnish or discolor. As far as cookware goes, items made from stainless steel indeed appear to need the least amount of maintenance and conditioning. From time to time, stainless steel will need restoring to keep it looking new. Prevent the problem of stains and discoloration by changing how you do things and learn some quick ways to fix them.

Stainless steel discoloration could be caused by heat, harsh chemicals, or incorrect use of stainless-steel cookware. Most discoloration is easily corrected with natural products like baking soda, vinegar, lemon juice, or club soda. Cleaners containing oxalic acid can restore stainless steel.

Stainless Steel Discoloration and Stains

Stainless steel, as its name indicates, does not technically stain. Staining usually refers to a situation where a substance has been drawn into the item. Discoloration of stainless steel is typically due to a build-up on the surface and thus is not a stain in the true sense. Several things can cause your stainless-steel cookware to show discoloration. Fortunately, there are quick and easy solutions to all of them.

What Causes Stainless Steel to Discolor?

Stainless steel is a compound (or alloy) made up of iron, carbon, and chromium. Iron and carbon are the two substances that are susceptible to rusting (also called oxidation). Chromium is added to prevent oxidation and give it the “stainless” quality. Adding the chromium creates a barrier between the iron and substances like oxygen and salt that cause rust.

In general, stainless steel with more chromium is a better quality stainless steel. Look for cookware with a 10.5% – 12% chromium content. The chromium layer that prevents rust is also the layer that causes the rainbow discoloration on your stainless-steel cookware.

  • When exposed to air, chromium creates a protective barrier. When this protective coat is exposed to high heat, discoloration occurs.
  • Harsh chemicals in cleaning materials can cause discoloration.
  • Calcium and other minerals in water can cause a build-up on your stainless-steel cookware that leaves white marks or spots.
  • Low levels of chromium in the cookware and very thin stainless steel can lead to utensils rusting.
  • Overheating oil in stainless-steel cookware can lead to brown residue discoloration.
  • High heat can cause a range of colors on your stainless-steel items.
  • Over time stainless steel can become dull.

How to Prevent Discoloration of Stainless Steel

Stainless steel is a fantastic choice for cookware due to its resilience and ability to stay looking good even after years of use. Fortunately, many of the factors that can cause your cookware to discolor are avoidable. Avoiding certain habits or changing the way you clean or use your stainless steel may prevent discoloration problems before they start.

Avoid High Heat

It is advised to heat your stainless-steel cookware with a small amount of oil on medium heat before using it to fry up food. This allows the oil to fill in tiny grooves in your cookware and assists with making it more stick-resistant.

An excessively high heat setting can cause discoloration. It will also likely cause food to stick and scorch the pan. If oil has been allowed to overheat in the pan, it could bond to your stainless steel and cause a brown build-up layer.

High heat used for outdoor grills can cause yellow, brown, blue, or black discoloration.

Avoid Harsh Chemicals

The use of harsh chemicals on your stainless-steel cookware can at best lead to a rainbow effect. An example of this would be washing your Stainless steel in a dishwasher with regular dishwashing detergent.

At worst, it can lead to corrosion in the form of pitting that cannot be repaired. This is true for detergents that contain chlorine or bleach and should be avoided altogether.

Avoid White Smudges and Spots

Water in some areas has a very high mineral content. In such places, calcium build-up is easily visible on stainless steel. By drying your stainless-steel cookware immediately after washing, one can avoid a build-up altogether.

Avoid Buying Thin Cookware

To reduce the cost of stainless-steel cookware, some sets are produced using a few layers, resulting in thin cookware. Often these will also have a lower percentage of chromium.

The result is cookware that can easily warp and has uneven heat distribution and resultant hot spots. Less chromium also means a higher chance of rust developing.

How to Fix Discoloration of Stainless Steel

In an ideal world, we could do all the right things, and our cookware won’t need repair and restoration. The reality looks a little different, though. One can easily misjudge the amount of water required to prevent food from scorching or getting burned, and then more than maintenance is needed.

Stainless steel is incredibly forgiving and can look as good as new with very little expense. The good news is that you most likely already have most products you will need to restore your stainless steel.

A few guidelines will always apply when cleaning stainless steel:

  • Never use hard and abrasive scrubbing tools like steel wool or a wire brush
  • When cleaning or rubbing, do not go against the grain of the stainless steel
  • Always use chlorine and bleach-free cleaning products

The solutions below will apply equally well to cookware, countertops, stovetops, grills and outdoor cookers, or your kitchen sink.

Removing a Rainbow Discoloration

Mix vinegar and water. A ratio of 1:3 works well. Spray this mixture on the affected surface. Leave it for a few moments. Wipe the solution away, rinse with clean water and dry with a soft cloth.

Removing Rust from Stainless Steel

Make a paste using water and bicarb. Apply it to the rust spot and leave this mixture on for a few minutes. With a motion that follows the grain, rub gently to dislodge the rust. Rinse away with clean water. Use a metal polish that contains oxalic acid to restore the shine. Rinse with water and dry.

Stainless Steel Stain Removed with Equal Part Vinegar and Water 1080
Removal of White Stains from a Stainless Steel Lid with Equal Parts Water and Vinegar

Remove Calcium Buildup and White Spots

Use vinegar and water (in equal quantities) on all white build-up. Allow it to stand for a while if the build-up is significant. Rinse away and clean with a soft sponge and water. Dry right away.

Remove Discoloration Caused by Heat

This type of discoloration only occurs with very high heat and can be seen on mended or joined items or outdoor grill cookers. Different colors occur when Stainless steel is exposed to temperatures ranging from 700 to 1200 degrees Fahrenheit.

Make a paste by combining club soda, vinegar, a bleach-free powder cleaner, and metal polish. Working with the grain, rub this mixture over the affected area. Rinse with water and dry. Polish using a product that contains oxalic acid.

Restore the Shine to Faded Stainless Steel

You can restore the shine of a faded countertop or basin by sprinkling the surface with baking soda. Next, spray the area with vinegar. Work the mixture together to spread it well. Drizzle a few drops of mild dishwashing liquid on the site and again work it in lightly.

Leave this mixture for an hour. Wipe the residue away and rinse well with water and a soft cloth. Restoring the beautiful shine of stainless steel is really as easy as that.

Is Stained, Rusted, or Discolored Stainless Steel Dangerous?

Providing the damage is only on the surface your cookware is safe to use. But be prepared for your ingredients to start to stick to the surface, thus affecting your cookwares performance. If the surface or your cookware is flaking or corroded it is time to replace it.

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Stainless Steel Stains and Discoloration

Stainless steel is a durable material that can last for decades, but it’s not invincible. Stainless steel discoloration may be caused by many different factors and requires special attention to remove or reduce the appearance of stains, spots, rust marks, heat damage, scratches, and other imperfections.

Fortunately, there are solutions out there to help you fix your stainless-steel cookware without breaking the bank! The best way to prevent these issues in the first place is with regular maintenance.

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