All the success comes from brewing tea leaves with cold water. Simply pour your favourite tea into the filter, pour cold water over it and place the bottle in the refrigerator. This brewing method allows for a smooth and rich taste without bitterness. The filter keeps the tea leaves inside for a clear brew. Hario Mizudashi is made of high-quality glass with elements of stainless steel and plastic. It is made in Japan with the highest quality standards. Another advantage of the bottle is the cleaning - it is dishwasher safe.