Almost every answer to this says the same thing: they are calcium deposits, simmer some vinegar, done. That is right about half the time. The other half is not a deposit at all — it is damage to the metal, it does not come off, and it is caused by a habit worth breaking.
The test that tells you which you have
Put enough white vinegar in the pan to cover the spots, warm it gently for a few minutes, then wash and dry.
The spots are gone. They were mineral deposits. Entirely cosmetic, and the pan is fine.
The spots are still there. Now run a fingernail over one. If you can feel it — a very slight roughness, or a catch, where the surrounding steel is smooth — that is pitting. It is metal loss, it is permanent, and no cleaning product will bring it back.
Those two results have almost nothing in common except their colour, which is why the standard advice frustrates so many people.
If they wipe off: mineral deposits
Hard water carries dissolved calcium and magnesium. When water evaporates or boils away, the minerals do not go with it — they are left behind on the metal as chalky white spots or a cloudy film. This is the same substance as the limescale in a kettle.
Boiling water in the pan is the usual culprit, especially boiling it dry or nearly dry, and it shows up worst in hard water areas. Boiling dry also risks warping the base out of true, which is a more expensive problem than a white mark. It is not a sign of a cheap pan or of anything you did wrong.
Removing it
- Cover the affected area with white vinegar, or a one-to-one mix of vinegar and water.
- Warm it gently — not a rolling boil — for five to ten minutes. The acid dissolves the carbonate.
- Tip it out, wash with hot soapy water, rinse and dry immediately.
For a stubborn film, a paste of bicarbonate of soda and water rubbed with a soft cloth after the vinegar step will finish it. Bar Keepers Friend, which is oxalic acid based, also works well on stainless and is worth having — but keep it away from coated pans, where abrasive cleansers cause the damage described in the guide to a non-stick pan that has started sticking.
Preventing it
Dry the pan rather than leaving it to drip. Do not let water boil away to nothing. In a very hard water area, filtered water for boiling makes a visible difference.
If they do not wipe off: pitting
This is the part the standard answer misses, and it has a specific and avoidable cause.
What is actually happening
Stainless steel does not resist corrosion because it is inert. It resists corrosion because chromium in the alloy reacts with oxygen to form an ultra-thin, invisible, self-repairing oxide layer over the surface. That passive layer is the whole reason stainless is stainless.
Chloride ions attack that layer. Where the layer is breached and cannot immediately re-form, corrosion eats into the steel at that one point — a pit. Pits are small, often shallow, and appear as dull white or grey specks that will not polish out, because there is less metal there than there used to be.
The cause: when you add the salt
Salt is sodium chloride, and the way most people salt a pan of water is close to the worst case.
Add salt to cold or still-heating water and it sinks. Undissolved grains sit on the base of the pan in direct contact with the steel, and in that tiny area the chloride concentration is enormously higher than in the water above. It sits there, undisturbed, while the pan heats. That is precisely the condition that breaks down the passive layer.
The fix costs nothing: bring the water to a boil first, then add the salt, then stir. In moving, already-boiling water the salt dissolves in seconds and never rests on the metal. This is why cookware manufacturers put it in their care instructions, and it is the single most useful thing on this page.
Other chloride sources worth knowing about
- Leaving salty or acidic food standing in the pan. Tomato sauce, brine, stock, anything with soy sauce — decant it rather than storing it in the pan overnight.
- Bleach and any chlorine-based cleaner. These are chloride sources by definition and should never be used on stainless cookware. This includes soaking in water with a splash of bleach to freshen it.
- Dishwasher detergent left sitting on a damp pan at the end of a cycle, particularly on the base.
Can it be fixed?
Not really, and it is worth being clear rather than hopeful about it. The pits are missing metal. Polishing removes surrounding material to bring the surface level with the bottom of the pits, which on cookware means removing a meaningful amount of steel for a cosmetic gain.
The good news is that it is very rarely more than cosmetic. Pitting does not make a pan unsafe or unusable, and a lightly pitted pan cooks exactly as it did before. It may stick slightly more in the affected spots, and if the pitting is severe and widespread the pan is nearing the end of a long life rather than suddenly ruined.
The other marks people call spots
Several different things get described as spots or stains, and they have different causes and different fixes.
Rainbow or oil-slick colours
Blue, purple, gold and green iridescence, usually appearing after the pan has been heated empty or run hot. This is heat tint: the passive oxide layer has thickened slightly, and the colours are an optical effect of light interfering within that film rather than anything deposited on it.
It is completely harmless and does not affect cooking. Vinegar or Bar Keepers Friend removes it if it bothers you. It tends to return, because the cause is simply using the pan hot.
A cloudy, chalky white film across the whole base
Usually starch, from boiling pasta, rice or potatoes, sometimes combined with mineral deposits. Vinegar handles the mineral part; a soak in hot soapy water and a nylon scourer handles the starch.
If the whole interior looks uniformly dull and slightly frosted rather than spotted, and it has been through a dishwasher many times, that is detergent etching. It is a very fine surface roughening and cannot be reversed, though it is purely cosmetic.
Blue or grey hazing
Overheating, usually from preheating empty for too long. Cosmetic, and the same acid cleaners lift most of it.
Brown or golden-brown patches that feel slightly sticky
Not a stain but polymerised oil — cooking oil that has cross-linked into a hard varnish on the surface. On stainless this is harmless and comes off with a hot soak and Bar Keepers Friend. On coated cookware the same substance is the cause of a non-stick pan that will not release food, and on cast iron the very same reaction is what you are deliberately creating when you season a pan. Same chemistry, three completely different verdicts depending on the metal.
Does a better pan resist this?
Partly, and it is worth knowing which parts money actually buys.
It does not make the pan immune to pitting. Every stainless steel used in cookware depends on the same chromium oxide layer, and chloride attacks all of them. An expensive pan salted in cold water will pit just as a cheap one does. The habit matters more than the price.
The alloy grade does shift the odds. Most cookware is 304, usually marked 18/10 or 18/8. Some higher-end and commercial pieces use 316, which contains molybdenum and is meaningfully more resistant to chloride pitting — it is the grade specified for marine and food-processing equipment for exactly that reason. It is not common in domestic cookware, and it is not worth hunting down solely to avoid salt marks.
Construction changes how often you boil it dry. A thin, single-ply pan with a hot spot over the burner runs dry in one place long before the rest, which is where mineral deposits concentrate and where overheating hazing starts. A thick disc base or fully clad construction heats evenly and forgives inattention. That is a genuine, everyday difference rather than a marketing point — the cookware set guide and the frying pan picks both note base construction, and the gas stove guide covers it for burners that concentrate heat in a ring.
So: buy for even heating and buy for the size you need, and salt the water after it boils. The second one is free and prevents more damage than the first.
The order worth working through
- Warm some vinegar in the pan for a few minutes, then wash and dry.
- Gone? Mineral deposits. Harmless. Dry the pan properly and stop boiling it dry.
- Still there, and you can feel them? Pitting. Permanent, cosmetic, and caused by chloride.
- Change one habit: salt the water after it boils, not before, and stir it in.
- Rainbow colours instead of white? Heat tint. Harmless, and vinegar removes it.
- Never use bleach or any chlorine cleaner on stainless, and do not store salty or acidic food in the pan.
How This Guide Was Put Together
Plainly: this is a research-based guide, not a hands-on test. I have not deliberately pitted a set of pans to compare outcomes, and nothing here is a report from my own kitchen.
What it rests on: the metallurgy of stainless steel, which is well established and not in dispute — corrosion resistance comes from a self-repairing chromium oxide layer, and chloride ions are the classic agent that breaks it down locally to produce pitting; the care instructions published by stainless cookware manufacturers, which is where the add-salt-after-boiling guidance comes from and why they bother to print it; and the chemistry of carbonate scale, which is why an acid dissolves mineral deposits and does nothing at all for pits.
What I could measure, and what I could not: only one competing page could be measured — the Wirecutter guide to cleaning stainless pans, at 1,694 words. The other results blocked automated access, so no word count is claimed for them and no field average is quoted. The one measurement is worth reporting though, because it supports the point this guide is built on: that 1,694-word page from a very authoritative publisher contains zero mentions of pitting, corrosion or salt. The permanent case is simply not covered.
What I could not establish: a water-hardness threshold above which deposits become likely. It varies with local supply and with how the pan is used, and any number would be invented.
Frequently Asked Questions
What are the white dots on my stainless steel pan?
Either mineral deposits left by hard water, or pits corroded into the metal by chloride. Warm some white vinegar in the pan for a few minutes: deposits dissolve and disappear, pits do not. If the spots remain and you can feel a slight roughness with a fingernail, they are pits.
How do I get white spots out of a stainless steel pan?
If they are mineral deposits, cover them with white vinegar, warm gently for five to ten minutes, then wash and dry immediately. A bicarbonate of soda paste or Bar Keepers Friend finishes off anything stubborn. If they are pits, they cannot be removed, because the metal is missing rather than covered.
Why does my stainless steel pan have white spots after boiling water?
Hard water. Calcium and magnesium stay behind on the metal when the water evaporates, exactly as limescale builds up in a kettle. It is worse if the pan is boiled dry or left to air dry. It is cosmetic and vinegar removes it.
Does salt damage stainless steel pans?
Salt added to water that is not yet boiling can. Undissolved grains sink and sit against the base, where the local chloride concentration attacks the pan’s protective oxide layer and etches small permanent pits. Bring the water to a boil first, then add salt and stir, and it dissolves before it can settle.
Is a pitted pan safe to use?
Yes. Pitting is a cosmetic and structural surface issue rather than a safety one, and a lightly pitted pan cooks the same as it always did. Food may stick slightly more in the pitted areas. Only very severe, widespread pitting is a reason to replace a pan.
What are the rainbow colours on my stainless pan?
Heat tint — a slightly thickened oxide layer producing an optical interference effect, usually after the pan has been run hot or heated empty. It is harmless, does not affect cooking, and comes off with vinegar or Bar Keepers Friend, though it will come back with use.
Can I use bleach to clean a stainless steel pan?
No. Bleach is chlorine based, and chloride is the specific thing that breaks down the protective layer on stainless steel and causes pitting. Soaking a pan in dilute bleach to freshen it is a reliable way to damage it permanently.
More cookware guides
For which utensils are safe on this material, see using metal utensils on stainless steel. If it is a coated pan rather than bare stainless, there is a separate guide to a non-stick pan that has started sticking.
Glenn is the founder of Kitchenware Compare and has spent years researching, testing, and reviewing kitchen appliances, cookware, and gadgets. A lifelong home cook raised in a family that treated every meal as an occasion, Glenn started this site to cut through the noise of conflicting product reviews and give readers honest, practical guidance. When he is not testing the latest air fryer or digging into the specs of a new espresso machine, he can usually be found experimenting with new recipes or hunting for the perfect cast iron skillet at a flea market.
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