I have this Bialetti Moka pot for over a year. I wasn't using it very frequently until a couple of months ago. Now I use it almost every day.
I think in last December, I made coffee and forget to remove the old coffee from the funnel and noticed it after one week. I cleaned it immediately with detergent and even rubbed it with a dishwashing brush... Then I made coffee again and it smelled horrible, like I wasn't able to remove all the leftover coffee. I noticed that some coffee was actually in the filter and I put one of the hairs of the brush inside every hole to get rid of the old coffee residues. Some of them were attached to each other with mold. It was a terrible experience to clean it, it took more than one hour. Then I brewed 2-3 times and throw away the coffee I made, just to make sure everything is actually cleaned.
I also noticed these spots at this incident. I am not sure if they were there before. I did some research on how to get rid of these spots and realised I shouldn't be cleaning the pot with soap... I don't use soap anymore.
I don't know what these spots are. I couldn't get rid of them and I thought maybe it is just oxidation. I still use the pot and coffee tastes normal, as it should be, but rarely I still get the smell.
Is there a way to get rid of these spots? How can I make sure that they are really oxidation? Should I keep using it?