Janet > wrote:

> 190 F is well below the boiling point of water (212F), so such hot
> water dispensers are no good for making tea.

They are actually not at all bad for making some kinds of tea, not even
all that bad for most kinds of black tea. Water should not be actually
boiling, as in rolling boil - for any kind of tea. The optimal stage for
most black teas is the so-called "white boiling," the one immediately
preceding the rolling boil - and one at which the temperature is still
below the boiling point of 100°C. You can actually see that stage if
you boil water in a transparent vessel. You can also hear it - it is
the loudest stage - that is when you are supposed to take your kettle
off the fire (or switch it off) at once, not waiting for the stage to
end or even to proceed.

I've been posting about this for decades; here are a couple of examples:
> or
<https://groups.google.com/forum/#!msg/rec.food.cooking/_xoFpRfNNys/nhJzdrGbpMYJ>
> or
<https://groups.google.com/forum/#!msg/rec.food.cooking/c56FOPnwxPk/kU_bJ76UftgJ>

Of course, all of this only matters if one really does care about one's
tea, using tea and water of the highest quality. If one adds sugar,
milk or anything else, the above doesn't matter much at all. Often
enough I drink tea with lemon; I use boiling water to make it.

Victor