Because the coffee oil comes off, I was washing it with hot water without using detergent. For 3 cups A popular series from Bialetti, an Italian coffee maker with a long history, the Moka Express Bialetti Moka Express made of aluminum - Brand: Bialetti - Model: Moka Express - With filter: Yes Purchased in January 2023, the bottom of the boiler has black stains because it was not used for a while without wiping off the moisture well. (Photo 13) It seems to be due to the corrosion of the aluminum. It seems that it is not harmful to the human body. There is melting of the plastic at the base of the handle (Photo 6) due to heat. If you prefer new items, are meticulous, or tend to complain, please refrain from purchasing. *Please consider purchasing only if you understand that this is a used item as it is stored by an individual. Thank you very much! *No claims, no returns.