Copper will not rust, but it will naturally tarnish or patina over time and/or with exposure to moisture. If you dry your piece thoroughly after each use, this will prevent tarnishing. If needed, your piece can be polished to a gleaming finish with a copper cleaning product such as Brasso, Tarn-x or lemon + salt. It takes only a few minutes to polish.
Do not put copper in the dishwasher, and never use steel wool or abrasive sponges or scrubbers to clean it, as they can scratch copper’s surface. Clean gently with a smooth sponge or cloth. Dry immediately. Any moisture left on copper will increase the rate at which it tarnishes, so be sure to dry it thoroughly.