Frestol sipper bottle Sipper is made of pure copper. Drinking water stored in copper bottles is strongly recommended by Science and Ayurveda because water stored in a copper bottle is loaded with anti-oxidants. Just fill this bottle and leave it for a minimum 3 hours, best if kept overnight as the water gets copper properties and its benefits during this time. Copper kills undesirable bacteria and germs and gets water charged with the health-benefiting qualities of copper. It is recommended to drink the water at room temperature, experts say that drinking from a copper water bottle on a regular basis, especially early in the morning, can make a significant difference to health.