Brewing tea leaves with cold water is the key to success. Simply pour your favourite tea into the filter, pour cold water over it and put the bottle in the fridge. This brewing method produces a smooth and rich flavour without bitterness. The filter keeps the tea leaves inside and ensures a clear infusion. Hario Mizudashi is made of high quality glass with stainless steel and plastic elements. It is manufactured in Japan to the highest quality standards. Another advantage of the bottle is cleaning - it is dishwasher safe.