Here in the Pacific Northwest, we have very high standards for water quality; however, while the water that comes out of the tap is safe to drink, that doesn’t mean that it tastes good. If you put even the hardiest fresh-water fish in water straight out of your tap it will die. It is the chlorine that kills, and I do appreciate the necessity for it in city water systems, but a liquid toxic enough to kill fish merely swimming in it and passing it through their gills is not something I want to consume, straight or with tea brewed into it. Thus, whenever possible, I avoid drinking straight-out of the tap water and I don’t make tea with it.
Filtered water is a little better than tap water. The chemicals and minerals are removed enough to result in a purer water, but the results are not altogether satisfying for me. I do not like the charcoal taste of water run through Brita filters. In my opinion Pur filters yield better tasting water, but I do not like the mechanism of the filters themselves. In my experience, the filtering methods that attach to the kitchen faucet are intrusive, get covered with mineral deposits and don’t stay on straight. Moreover, I do not like any of the container methods used with these filtering products because the vessels are plastic and also collect algae and other undesirable microbes. So, while the results are better than unfiltered tap water, I find these home purification methods unacceptable.
I do not want water that has had the bad stuff removed. I want unadulterated water from a pure source. This also rules out commercially available bottled water that has been purified or filtered by the bottler.
My experience with brewing teas with spring water have been very good. In Japan and China, nearly all sources, from conventional wisdom to the most stringent and formalized tea protocols, state that the ideal water for tea is mountain spring water. If you are positioned conveniently close to an actual mountain spring, then this is an easily obtainable substance. If you are, like most of the rest of us, living in a city, this is not as easy. There are, however, quite a few types of good bottled spring water available. Basically what to look for is pure spring water, bottled at the source. It is exceptionally nice if it is in a glass container, but I’ve only found one brand from Italy that was in a glass bottle and it was too small to be practical for keeping at home for brewing tea. I always pour the water immediately into a glass container once I get it home. There are slight variations
between types of commercially available spring water, some of which are going to come down to individual preference. Hibiki-an has a very useful list of recommended brands of bottled water that work well with green tea.
My essential point is that water, making up such a large portion of the substance of that wonderful drink called “tea,” should not be overlooked as an important element. I am aware of the differences in taste between teas brewed with tap water and teas brewed with spring water, and I can’t find any good reason to settle for the former. At 8 pounds per gallon, transported water is a bit of a hassle, but I am more than willing to carry water jugs down the 78 stairs to my house to ensure that my tea tastes better.
For more reading about tea and water, there is an excellent article on Choosing Water for Tea: A Simple Guide on Stéphane Erler’s Teamaster blog. He also has a great article on his experiments with different kettles and their effect on heating water for tea and one on Chinese water for Chinese teas.