How do I clean an aluminum pan that turned black from boiling water in

Quick fix. I usually keep the two large bottles of lemon juice on hand (from sam`s) for this. After pasta or other water based boil in my aluminum pots, I put a few good squirts of the lemon juice in water to the dark line and let it boil for a few minutes. You can see the oxidation vanish after a few! Then I lightly run an SOS pad to shine it up! Sorry for being so wordy...

You can try this aluminum cleaning hack: https://www.hometalk.com/diy/repair/windows/aluminum-window-frames-cleaning-restoring-4040162