So my aunts were over last week and being perfectly well-intentioned, helped me clean up the kitchen and ended up putting my 8” aluminum cake pan in the dishwasher. It’s your standard heavy cake pan, I think from William Sonoma. The next morning when I was emptying the dishwasher, I saw the cake pan—it was a darkish color, and almost seems to have some pitting in it. I wiped it and wiped it with a paper towel and the black stuff kept rubbing off. Is it ruined? And why would putting it in the dishwasher cause such a reaction?
I have historically put all of these pans in the dishwasher. I’ve never seen pitting, but others here have reported it. The pans do get a film of what I assume to be aluminum oxide on the surface. It will wipe off after you go through a number of paper towels and maybe the blue type scrubbing pads; the pans certainly aren’t ruined, unless you have aluminum coated steel, then “maybe”. I have since stopped putting the uncoated aluminum in the dishwater, since the effort to scrub off the film is greater than cleaning them.
(BTW, I think the Williams Sonoma stuff is aluminum coated steel; I won’t buy those anymore because the steel can rust beneath the aluminum.)