Importance: Please keep the pot dry after every time use, we recommend you use a napkin, cotton cloth or other better water absorption tool to wipe it clean. Then put it in a dry place to prevent oxidation. When you receive it, please apply salt and toothpaste (or onion and salt) on the pot surface, wait it to dry then use towel to wipe it clean. Since copper ion is very unstable, so it can be easily oxidized and rusted. To ensure pure copper substances, we have no other plating oxidation coating. Copper oxide is non-toxic, it does not affect usage and function. If it oxidized to bronze or black, Please don’t worry, simply apply vinegar and salt in 1 : 1 ratio portion, rub or scrub on surface, then you can remove the oxide layer. You can also use scourer stained with detergent to wipe it clean, to regain brightness and shininess. But if you don’t do any maintenance or appear patina, we recommend you use sandpaper to sand off the rust. Please note this link is for one piece pot with lid. Customer service: We highly value your satisfaction. We will take your case very seriously and we guarantee to offer you a happy solution very promptly.