How to Clean Aluminium Vessels: Remove Blackness & Stains
The blackness on aluminium utensils is a dark film that builds up on the metal with use. It is not rust. Hawkins, the Indian pressure cooker maker, says the darkening inside its aluminium cookers comes from minerals in the water, and that it is not harmful. The quick fix is a mild acid. Boil water with lemon juice or cream of tartar in the pot. Then wash it and dry it.
Most Indian kitchens have a few aluminium vessels, like topes, patilas and pressure cookers. They are light, cheap and good for cooking. But they turn black over time. Many people do not know why, or how to clean them safely. This guide shows you how to clean aluminium utensils at home, step by step.
Why Does Aluminium Turn Black?
Black aluminium does not mean the vessel is ruined. The change is only on the surface. Here is what causes it:
- Long boils in hard water: Dal, rajma and chole cook for a long time in a lot of water. The minerals in that water stay on the metal. If you add baking soda to soften chole or rajma, the pot can darken faster.
- Hard water: Water with a lot of minerals leaves a dark film. Hawkins says this is why the inside of its aluminium cookers can turn darker.
- Baking soda: Baking soda is alkaline. Alkalis attack aluminium. Strong ones, like caustic soda, dissolve it even at room temperature.
- Dishwasher: Hawkins says its aluminium cooker body may tarnish in a dishwasher.
Aluminium does have its own oxide layer. But that layer is very thin, about 5 nanometres, and it protects the metal (Wikipedia: Aluminium). The dark film inside a cooker is different. Hawkins says it comes from minerals in the water. It says this darkening does not harm your health or change the taste of food. The good news: it comes off with a mild acid.
Method 1: Cream of Tartar (Best for Light-Medium Blackness)
Step-by-Step
- Mix 2 tablespoons of cream of tartar with enough water to make a paste.
- Apply the paste to the blackened areas.
- Let it sit for 5-10 minutes.
- Scrub gently with a soft cloth or sponge in circular motions.
- Rinse thoroughly with clean water.
- Dry immediately to prevent water spots.
Why it works: Cream of tartar (potassium bitartrate) is a mild acid. It loosens the dark film on the metal. Do not leave it on for hours. Hawkins warns not to leave acids like lemon juice or vinegar standing in an aluminium cooker.
Where to buy: Look in the baking section of a supermarket. A small packet lasts many cleanings. Prices vary by brand and pack size, so we do not list one here.
The Hawkins Method for an Aluminium Pressure Cooker
Hawkins gives its own recipe for dark stains inside an aluminium cooker. Fill the cooker half full with water. Add 2 teaspoons of cream of tartar or lemon juice for each litre of water. Bring it to full pressure on high heat and cook for 15 minutes. For stains in the top half, do not pressure cook. Fill the cooker with the same mix to cover the stains and boil for 30 minutes. Then wash it and dry it with a soft, clean cloth.
Method 2: Lemon Water Boil (Best for Heavy Blackness)
Step-by-Step
- Fill the blackened aluminium vessel with water — enough to cover the dark areas.
- Cut 2-3 lemons in half and drop them into the water.
- Bring to a boil and simmer for 15 to 30 minutes. Check it at 15 minutes.
- Let the water cool to a comfortable temperature.
- Use a soft cloth to gently wipe the inside — the dark layer should lift off easily.
- Rinse with clean water and dry immediately.
Why it works: Lemon juice has citric acid. Heat helps the acid work faster. Together they loosen the dark layer so you can wipe it off.
For external blackening: Make a paste of lemon juice and salt. Rub it on the outside, scrub gently, and rinse. The salt scrubs while the acid does the work. Rinse it off right away. Hawkins says salty liquid left on aluminium can pit the metal.
How to Clean Burnt Aluminium Utensils
Burnt food is stuck food, not the dark mineral film. So treat it first. For a pressure cooker, Hawkins says to pour in enough water to cover the burnt area, but not more than half full. Close the cooker and bring it to full pressure on high heat. Lower the heat and cook for 5 minutes. Let it cool on its own, then open it, wash it and wipe it dry.
For an open patila or kadai, soak the burnt part in hot water first. Then use a plastic scrubber and a mild cleanser. Hawkins says a fine soap-filled steel wool pad can be used for stubborn spots, but only a little, because it can damage the surface. For more ways, read our guide on how to clean burnt vessels with kitchen ingredients.
How to Clean an Aluminium Pressure Cooker From Outside
The outside of a cooker gets baked-on stains from oil and gravy. Hawkins says to wipe off any fat or gravy from the base before you put it on the stove. Keep the stove top clean of oil drips too. If a stain bakes on, deal with it while it is still fresh. Soak it in hot water. Then scrub with a plastic scrubber and a non-abrasive cleanser.
Some dullness is normal. Hawkins says aluminium loses its shine over time, and this is the normal way the metal ages. For a brighter look, use the lemon and salt paste above. Rinse it and dry it well.
एल्युमिनियम के बर्तन का कालापन कैसे साफ करें? (Hindi)
- बर्तन में आधा पानी भरें। हर 1 लीटर पानी में 2 छोटे चम्मच नींबू का रस या क्रीम ऑफ टार्टर डालें।
- इसे 30 मिनट तक उबालें। प्रेशर कुकर में पूरा प्रेशर आने के बाद 15 मिनट पकाएं।
- पानी फेंक दें। नरम कपड़े से साफ करें, धोएं और तुरंत सुखा लें।
- जले हुए बर्तन में जली जगह तक पानी भरें, गरम करें और ठंडा होने दें। फिर प्लास्टिक स्क्रबर से धीरे से रगड़ें।
- बेकिंग सोडा, ब्लीच, खुरदुरा पाउडर या डिशवॉशर का इस्तेमाल न करें।
- खट्टा या नमकीन खाना एल्युमिनियम के बर्तन में न रखें।
In English: half fill the pot with water. Add 2 teaspoons of lemon juice or cream of tartar per litre. Boil for 30 minutes, or pressure cook for 15. Wash and dry it. For burnt food, soak and heat it first. Skip baking soda, bleach and the dishwasher.
What NOT to Do with Aluminium
These common mistakes damage aluminium vessels permanently:
| Mistake | Why It Is Harmful |
|---|---|
| Using baking soda directly on aluminium. | Baking soda is alkaline. Alkalis attack aluminium and can make it darker, not cleaner. |
| Scrubbing with steel wool. | Scratches the surface. Hawkins says to use a fine soap-filled steel wool pad only sparingly, because it can damage the surface. |
| Using bleach or caustic soda. | Caustic soda dissolves aluminium, even at room temperature. Hawkins says not to use bleach or abrasive powders on its aluminium cookers. |
| Putting aluminium in a dishwasher. | Hawkins says its aluminium cooker body may tarnish in a dishwasher. |
| Soaking in water for hours. | Hawkins says salts in the water and old food can pit the metal. Aluminium can also pit if it is left wet. |
| Leaving lemon juice, vinegar or salty food in the pot. | Hawkins warns against it. Germany's food safety institute, BfR, says not to cook or store sour or salty food in uncoated aluminium pots. |
Key principle: Use only mild acids, like lemon, cream of tartar or vinegar, and only for a short clean. Then rinse and dry. Never use strong alkalis or harsh abrasives.
How to Keep Aluminium Shiny Longer
- Use steel for sour or salty dishes: The BfR advises against cooking or storing acidic or salty food in uncoated aluminium. Use stainless steel for tamarind, tomato and pickle dishes.
- Hand wash only: Never use a dishwasher for aluminium vessels.
- Dry immediately after washing: Hawkins says aluminium can pit if it is left wet.
- Clean monthly: A quick cream of tartar wipe once a month helps stop heavy buildup.
- Use soft sponges: Avoid steel wool and abrasive pads on aluminium.
- Add a little acid to plain water: The Hawkins BigBoy manual adds 1 tablespoon (15 ml) of lemon juice or vinegar to 1 litre of water to stop the cooker from discolouring.
Own an aluminium moka pot? It needs gentle care too. Our moka pot listing says to rinse it with warm water only and never put it in the dishwasher. The BfR says a dishwasher can strip the protective layer that forms inside an aluminium espresso maker. Read more on why a moka pot should not go in the dishwasher.
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Frequently Asked Questions
Why does my aluminium vessel turn black after cooking dal?
Dal cooks for a long time in a lot of water. The minerals in that water leave a dark film on the metal. Baking soda, if you add it, can make it darker. Hawkins says this kind of darkening is not harmful and does not change the taste of food. A lemon or cream of tartar boil removes it.
Is the black layer on aluminium harmful to eat?
Hawkins says the mineral darkening inside its cookers is not harmful. The metal itself is a separate question. Europe's food safety agency, EFSA, set a safe limit of 1 mg of aluminium per kg of body weight each week. Germany's BfR says sour and salty foods pick up the most aluminium from uncoated pots. So do not cook or store them in one. Use aluminium for water and neutral foods.
Can I use vinegar to clean aluminium?
Yes. White vinegar is a mild acid, like lemon juice. The Hawkins BigBoy manual adds 1 tablespoon (15 ml) of lemon juice or vinegar to 1 litre of water to stop the cooker from discolouring. Do not leave vinegar standing in the pot. Rinse it and dry it.
How often should I deep clean aluminium vessels?
Once a month for vessels you use often. A quick cream of tartar wipe helps stop heavy buildup. For vessels used only to boil water, every 2-3 months is usually enough.
How do I clean an aluminium pressure cooker from outside?
Clean baked-on stains while they are fresh. Soak the cooker in hot water, then scrub with a plastic scrubber and a mild cleanser. For dullness, rub on a lemon and salt paste and rinse it off right away. Do not use bleach or abrasive powder.
How do I clean burnt aluminium utensils?
Cover the burnt part with water and heat it. In a pressure cooker, Hawkins says to use no more than half full, cook at full pressure for 5 minutes and let it cool. Then lift the food off with a plastic scrubber, wash and dry.
Should I replace blackened aluminium vessels?
Usually not. The blackening is only on the surface, and Hawkins says some loss of shine is normal for aluminium. Clean it with the lemon boil or cream of tartar method and it will look much better. Replace it if it has deep pits, dents, holes or warping.
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Sources & References
- Hawkins Cookers, Care & Cleaning: darkening from minerals in the water is "neither injurious to health nor does it affect the taste"; 2 teaspoons cream of tartar or lemon juice per litre, 15 minutes at full pressure or 30 minutes boiling; burnt food, pitting, bleach, steel wool and dishwasher advice.
- Hawkins BigBoy pressure cooker manual (PDF): 1 tablespoon (15 ml) lemon juice or vinegar in 1 litre of water to prevent discolouring.
- German Federal Institute for Risk Assessment (BfR), FAQs about aluminium in food: EFSA tolerable weekly intake of 1 mg per kg body weight (2008), JECFA 2 mg per kg (2012); no sour or salty food in uncoated aluminium pots; dishwasher and aluminium espresso makers.
- Wikipedia, Aluminium: the protective oxide layer is about 5 nm thick; aluminium reacts with sodium or potassium hydroxide at room temperature.
- InstaCuppa Classic Aluminium Moka Pot listing: warm water only, never in the dishwasher. Card prices and stock checked on our store on 29 September 2026.
We did not lab-test these methods. The steps follow the cooker maker's own care guide.
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