Rustik Craft copper glasses healthful benefits. Storing water for three hours in copper tumbler is known to kill harmful bacteria and prevent certain diseases. It is also known to prevent premature aging.Use these water glasses along with other copper tableware items to get an authentic Indian dining experience. It’s recommended to drink the water at room temperature. The copper cups should not be stored in fridge. Copper darkens naturally over a period of time. The copper cup requires cleaning from time to time. Use lemon juice or tamarind to rub the utensils. Leave it for few minutes and wash with water.