Ovearheated/burnt my copper pot, is it still usable?
Try boiling a mixture of water and baking soda and then turn off the heat and let it sit until it cools enough to scrub. You might try 1/2 cup baking soda to a quart of water. Another trick is a baking powder paste. Same idea but more intense. Make a paste, bring to a boil only briefly and then scrub.