(Did we ever decide what what tea is, by the way?)

Peter


"Lewis Perin" > wrote in message
news
> "Dog Ma 1" (reply w/o spam)> writes:
>
> > [...caffeine and steeping...]
> >
> > I'm going to hazard a guess that for most teas, a few minutes in tepid
water
> > will take out most of the alkaloids and not much else. That five seconds
in
> > hot water will take out 90% from anything. And that in fannings/dust and
> > even small broken-leaf blacks, with most of the taste in dried surface
> > exudates, only cold water will remove buzz w/o taking away too much
flavor.
>
> I've just been trying to find some data on caffeine's extraction from
> tea leaves as a function of steep temperature and time. (Using the
> lazy man's research tool: Google.) Regarding temperature, there's
> lots of talk about how lower steep temperatures slow down the
> extraction, but not numbers.
>
> A Canadian university student health pamphlet
>
> http://www-health.concordia.ca/healt.../caffeine.html
>
> cites these caffeine concentrations:
>
> Tea (5 oz)
>
> Brewed for 3 minutes--------------------------- 20-46
>
> Brewed for 1 minute -----------------------------9-33
>
> That is to say, after steeping 1 minute at an unspecified temperature
> (but most people would assume near boiling) at least 11 to 13 mg of
> caffeine is yet to emerge from the leaves.
>
> A British government study
>
>
http://archive.food.gov.uk/maff/arch...144/annexc.htm
>
> found that a 1-minute infusion from a teabag had 30% less caffeine
> than a 5-minute infusion. They're talking about finely chopped leaves
> here, and presumably very hot water, and still 30% remains after a
> minute.
>
> > That's an informed guess, because it's what I do. Too much caffeine just
> > keeps me awake at night; I only have a cup every month or two,
>
> Are you referring to coffee here? Or late-night tea?
>
> > and have a low tolerance. Theophylline OD makes me quite ill. So if
> > I'm having more than one mug of strong Assam or one pot of sencha,
> > I'll wash out most of the theophylline per above. Cold water seems
> > to work pretty well, though I have yet to try it on expensive
> > oolongs.
>
> I'm a little dubious about cold water, because I actually use tepid
> water a lot to brew tea in the summer. (I don't really like iced
> tea.) I find that a 15-minute steep of a green yields a delicious cup
> with no astringency at all, which gives a kind of creamy mouth feel.
> I've no idea how much caffeine there is in the cup, but clearly a lot
> of the good stuff in the leaves comes out in 15 minutes, so I'm not
> sure I'd want to toss the liquor from a 5-minute steep in tepid water.
>
> /Lew
> ---
> Lew Perin /
> http://www.panix.com/~perin/babelcarp.html