Question about water temperature

[fuzzer37]

I use a metal ketle to boil water on a gas stove, and usually i'll just wait until it's whistling. But i've recently got some more delicate white teas that i would like to infuse at a lower temperature (at least <90 C). Is it a bad idea to add a few ice cubes to the kettle to bring the temperature down? Or will that ruin the water?

[debunix]

One traditional option for this situation is to pour water into a yuzamashi, a simple open vessel to let the water cool down in until it reaches infusion temperature (using a thermometer if you like to check it). My variation on this, when I'm not using a kettle that lets me set the temperature, is to pour some hot water into a yuzamashi and add cold water (even ice) to that, but not to the kettle--I'm going to want the kettle to stay hot for the next infusion.

[bonescwa]

Just pour the water a few times back and forth between two vessels until it seems cool enough. Touch the edges of the vessel and judge the heat of the water that way. I would suggest trial and error over a thermometer. I've found this is a quick way to take the edge off of boiling water and is suitable for most tea (unless they are/you are very particular).

[Chip]

I pour water into a yuzamashi (any open pitcher that can take heat will work), and then to my teapot before adding tea!), and then to my teacups and then if needed back to the yuzamashi. You can vary the rotation as needed.