Oxidation is the reaction between metal and oxygen, which often results in a brown or black residue that can be flaky or powdery. Aluminium pans tend to oxidise quickly. Therefore, removing these black or dull brown deposits from your aluminium cookware can be an ongoing process.
Fill the sink with hot water. Add five drops of liquid dish soap and mix until the water is soapy.
Submerge the pan in the hot water and let it sit for two minutes.
Scrub the entire pan with a scrubbing brush or a piece of superfine steel wool. Don't use coarse steel wool as it will scratch the soft aluminium. Work until the aluminium is clean and the oxidation is gone.
Fill the pan with clear water if any stains remain. Add 1/2 cup white vinegar. This acidic solution will react with the oxidation to remove it.
Boil the water on the stove for 15 minutes or until the oxidation is gone.
Let the pan cool and pour the solution down the drain.
Rinse the pan with clear water and dry it completely with a clean cloth.