I made (delicious!) mashed sweet potatoes in a conventional stove-top pot, covered the pot with Reynolds aluminum foil, then put it in a still warm but off-position oven (simply to save stove-top and counter space for the moment while wanting it to stay at room-temperature). Retrieving the pot a few hours later, I found that the inner surface of the foil had turned a light brown. It was also moist from the condensation, but had remained clean, unoiled, unburnt. I've cooked quite a bit and never seen this. What could be causing such discoloration, and is it a worrying symptom (of, say, toxins in the foil)? [more inside]
posted by taramosalata on Dec 14, 2008 - 6 answers