Traditionally in India, people used to drink water from a copper vessel. Slowly, over a period of time, this tradition was lost to modernization.

Now, again people are realizing the hidden goodness in copper vessels. But we have to consider a few facts before utilizing these valuable copper vessels.

1. As set by the World Health Organization, drinking water stored in pure copper vessels has a maximum permissible limit of copper of 2mg/liter. If it goes above the permissible limit, then the stored water will have a change of color and a bitter taste.

2. The copper vessels used for drinking water can be cleaned on the outside, preferably every day, with vinegar, tamarind, or lemon with some salt, then thoroughly rinsed with water. For inside the copperware, boil one tablespoon of salt and one cup vinegar and leave it inside for a few minutes and then scrub inside and rinse afterward. The artificial cleaning agents are rough for the copper, and they are harmful to the digestive system as they are ingested along with the drinking water.

3. Drink water from a copper vessel for about three months, and then leave it for a month. Then you can start drinking water again from a copper vessel. This will prevent any excessive absorption of copper in your system.

4. Never heat or prepare food in an uncoated copper vessel. Do not store any curries in them, because the chemical reaction between copper and the food will make the food uneatable.

5. Never keep or drink hot water from a copper vessel. By following these maintenance tips for copper, you can use your copperware safely and effectively.

References
https://www.wikihow.com/Clean­-Copper

http://www.ishafoundation.org/us/blog/properties­of­ copper/\

http://www.homeoint.org/morrell/articles/pm_metal.htm

https://www.ncbi.nlm.nih.gov/pubmed/9587153

https://www.ncbi.nlm.nih.gov/pubmed/12010579