How to clean a copper water bottle? How often should you clean it?
A newly-purchased copper bottle or vessel needs to be cleaned before you use it for the first time. You can follow the steps given below for cleaning/rinsing your copper bottles (at any given point of time):

Step 1: Wash the copper bottle with normal water
Step 2: Use a mixture of lime, salt, and vinegar to clean the inside portion of the bottle
Step 3: Use mild soapy water to clean the outer surface and wipe with soft cloth whenever necessary
Step 4: Rinse the bottle with normal water and leave it to dry
Step 5: Cleaning should be done at least 2 to 3 times a week on the inside.

Make sure you avoid using harsh detergents, soaps or scrubs on either the inside or the outside of a copper bottle, since this may damage the surface. Due to oxidation, it is natural and completely normal for copper bottles to get stained or darken in colour with time, but cleaning them using the aforementioned step-wise process can ensure that your bottles stay clean and last longer.