Originally Posted by UnderPressure
Quick question- I just scrubbed the bottom of my aluminum brew pot with regular dish washing liquid, water, and a Scotch Brite sponge, and the water turned black. Should I be concerned about this?
Inside: that was the oxidized layer and is a good thing. If you scrubbed it all off, boil a full pot of water for at least 30 minutes before brewing again to re-establish an oxidized layer.
Outside: That may have been oxidation or soot from your burner or both. On the outside you don't have to worry. Just let it dry and get ready to brew another batch.
I usually just use hot water and a cloth to clean my aluminum pots. The dried wort is mostly sugar and the water dissolves/loosens it and the cloth is really all that is needed to remove the grunge.