Uh huh, I was taught to do that to lower the caffeine content but I'm not sure it deals with the tannin. I think tannin is reduced by the length of time in the water? That said, friends returning from working in the People's Republic tell me its common to put some loose tea leaves in a jar, never removing them, and just replace the water all day long as its drunken.chas wrote: I was taught by a Taiwanese buddy to use boiling or near-boiling water, but to cover the leaves, steep for maybe 30 seconds, then strain and throw that brew out. Then pour more water on the leaves, steep for a few minutes, and drink thaa. He would even drink the third brew, although I found that a bit watery. It's similar to using non-boiling water, the acid doesn't build up.
If drinking tea using bags I'll use the same bags several times but I personally never infuse for longer than 2 or 3 minutes.
As for the temperature, I mentioned my hot pot serves water at 208 degrees. Its Japanese so I'm assuming they did studies on what their population prefers. When boiling water at the stove a friend told me to count to 60 (to let the temperature lower a smidgen) before pouring it over the leaves.
This tea I bought that was specially blended for making Sweet tea (the stuff I think has had its tannin level lowered) they say I can make it with hot water or set it in the sun to steep. If one did that, made it as a "sun tea" its a matter of the length of time and not degree of heat that is employed.
Interesting.
When making infusions of herbs its a combination of length of time and degree of heat. Some teas release the desired chemical constituents better in unheated water.
With herbal teas there's various preparation protocols depending on what herb is used and what one is trying to accomplish by consuming it.