Water quality and temperature
Water quality has a great effect on the quality of tea. The more delicate the tea, the more important the water quality. In general, if you like the taste of your tap water, it will probably make good tea. If not, use a good bottled water or a filter to remove chlorine.
Do not use distilled water, as it lacks the minerals that bring out the flavor of tea.
The right water temperature is key to preparing quality tea. Most black and oolong teas should be infused with water that has just come to a full boil, approximately 200 to 210 degrees F. Limited boiling increases the amount of oxygen in the water and creates a fresher-tasting tea. However, if the water continues to boil it will loose oxygen and taste flat.