"Jon Nossen" > writes:

> [...bags, grinding, and caffeine...]
>
> > > So is the amount of caffeine in white tea consisting of *whole
> > > leaves or buds* similar to the amount in *finely ground* tea?
> > > Just wondering.
> >
> > Unless the grinding adds or subtracts caffeine, both of which seem
> > rather unlikely to me.
>
> Not quite. The grinding makes sure that *all* the caffeine in
> the leaves is extracted, as with Matcha tea, instead of an
> amount *somewhat less* than that - of course, how much less will
> depend on the particle size of the tea before grinding, the
> water temperature and the steeping time.
>
> Which is why I wonder how useful the stated caffeine amounts
> really are.

I think they're useful as long as we're clear on what they are and
what they aren't.

They *are* a standardized (loosely speaking) measurement of caffeine,
applying the same measurement technique to all samples. That's the
reason they ground up the leaves, I'm sure.

They *aren't* a direct indication of how much caffeine gets into the
cup when you brew 2.0 grams of each tea "the right way", because "the
right way" will vary the temperature and steep time depending on the
type of tea. Let's not even think about how many "right ways" there
really are to brew a given type of tea!

What would make these measurements a lot more useful would be some
rules, however imprecise, for calculating caffeine uptake according to
brew temperature and steep time. A year or two ago on RFDT there was
an interesting thread ("Strong, Cheap, Black Tea") that made some
progress on this, but I think temperature was ignored.

Are you listening, Dog Ma?

/Lew
---
Lew Perin /
http://www.panix.com/~perin/babelcarp.html