You did some homework so I'll take the time. The different rates of
solubility for any perceived tea taste is a meaningless factoid
argument. The fundamental fallacy on which your argument really hinges
is they turn on at different times so you can claim a taste like
'sweetness' not present in the first cup. That sweetness is present in
the first cup along with any other tasting component you wish to
describe. The fact you taste it in any cup is the accumlation of that
particular taste chemistry on your tastebuds. It doesn't act as the
rabbit in the hat. Gongfu in particular depends on this through
saturation. Some teas are noted for their finish. Puerh in
particular. The ghost in the machine translation calls it 'returns to
Ganzu' meaning aftertaste. I only argue that caffeine is part and
parcel of the complete taste spectrum in tea. If no taste no caffeine.
Caffeine is water soluable and some components aren't so can only be
leached. That is the process of moving the elements through the cell
membraine. Notice a spent leaf is still a leaf. It is the process of
extraction. AFAIK soluble means simple chemical binding so in this
case the caffeine can sneak through the cell membrane hitched to a
water molecule. Leaching results from the break down of a barrier and
allows separation of components. The cell walls are broken down by
water solubility releasing the components of taste. I would imagine at
this point the cell walls look like cheese. The cell walls in green
tea haven't been maserated through oxidation like the black. So black
infuses faster that green. I accept the percentage of caffeine by leaf
weight. I give you the weights from any table. I said that more than
once. It's like using wind chill or heat index to describe weather.
Yeah so what. However that roughly leaves most of the leaf weight to
something else. Caffeine increases the absorbtion of nutrients through
the stomach walls. That is uncontestable like your caffeine weights.
I'll call that a meangingless factoid but it does account for an empty
upset stomach. So lets jump too your favorite subject Puerh. A gram
of Puerh has more 'taste' than a gram of white tea. They both maintain
a taste through multiple infusions. However that 'taste' in the white
tea will require more comparative weight. You pick the number two,
three, four, whatever times. Ergo more caffeine using your percentage
by weight proposition. I also claim the caffeine percentage is also
'proportionally' distributable among infusions according to taste if
the tea supports it. You may not notice that perse from infusion to
infusion over a short time period but let a pot sit between infusions
and you'll notice the caffeine effects. You don't so much taste
caffeine but notice the physiological reaction. And putting on my
science cap I don't see much analysis of the multiple infusion style
tea compared to a single infusion style tea noted in your footnotes so
anecdotally I stick with my claim of proportional taste and caffeine.
A weak cup of tea taste like a strong cup accept only in the
concentration of solution. I think I could dig up a few mass
spectrometry articles about tea which supports this claim using PubMed.
We all agree it is easy to moderate any tea taste including caffeine
by volume, weight and time making any percentage by weight argument
your chance of winning the lotto. It simply reduces to, no taste no
caffeine, because ultimately different solution rates are nothing more
than concentrations which we call tea taste. IMHO is based on
experience. You show me where 80% of the caffeine goes and I'll show
you where 80% of the taste goes. There is nothing left but 20% taste
and caffeine. That can be a single or multiple infusion depending on
the tea.

Jim

Mike Petro wrote:
> On 22 Aug 2005 07:30:19 -0700, "Space Cowboy" >
> wrote:
>
> <major snippage and quoting>
> >I think caffeine is directly proportional to taste. It is just another
> >component that makes up tea taste. A weak tasting second cup means
> >much less caffeine than the first. If multilple infusions hold up in
> >taste then more caffeine in each cup.
>
> Your argument is weak, my tea is not....
> Here's Tea Chemistry 101:
> The perceived flavor of tea is composed of many components. Each one
> of these components has a different solubility rate; hence the longer
> the leaf is in solution the more you will get out of the lower
> solubility items, and conversely, the higher solubility components
> will reach exhaustion earlier. Naturally, temperature will also affect
> the rate of extraction. Some of the more commonly identified
> components are as follows:
> Flavonoids such as theaflavins and thearubigins
> Polyphenol
> Amino acids
> Caffeine
> Catechins are the tannins responsible for tea's astringency, and green
> tea contains high concentrations. When green tea is fermented into
> black tea, the catechin content diminishes.
>
> Here is an interesting link describing the specific component and its
> associated flavor note. Please notice that caffeine is not among them.
> Caffeine is generally considered to add "briskness" but not flavor.
> http://www.teatalk.com/science/compounds.htm
> And another:
> http://www.fmltea.com/Teainfo/tea-chemistry%20.htm
> Also See Table 4.1(3)
>
>
> >Most of the elements that make
> >up tea taste are determined by leaching rates and not solubility.
>
> Webster says: "Solubility: the extent to which one substance is able
> to dissolve in another"
> Webster says: "Leaching: intransitive verb; to lose soluble material
> by dissolution"
> Again, I ask what is the difference? Every bit of education I have
> tells me that solubility is the relevant principle, and "leaching," as
> you put it, is just another facet of solubility.
>
>
> >So when we speak of caffeine water
> >solubility that doesn't preclude a leaching rate which might be similar
> >to the other taste components.
>
> I do not disagree. It doesn't preclude other components from having
> similar solubility, but that wasn't the point. The point with which I
> disagree is your equation of a proportional relationship between taste
> and caffeine, and I am challenging you to prove it with more than
> loose assumptions. I believe there are many teas (most notably puerh)
> that maintain a substantial, and, in some cases, preferable, amount of
> flavor even after the caffeine is predominantly extracted.
>
> "Due to the water-solubility of caffeine, much of it is extracted from
> the leaf in the first 20-30 seconds of infusion, allowing you to
> "decaffeinate" it yourself by steeping the leaves for approximately a
> minute and discarding this first infusion. Then proceed as usual,
> allowing slightly more time to achieve the desired strength.
> (Employing this method, of course, will naturally sacrifice some
> flavor.)" (2)
>
>
> >It
> >is the cultivar and not some given rate of caffeine solution for all
> >teas. Duh.
>
> Camellia Sinensis has caffeine levels of approximately 2.5 - 4%.
> However, the distribution of caffeine in the plant depends on the part
> of the plant from which it is derived. For example:
> Bud 4.70 % First leaf 4.20 % Second Leaf 3.50 % Third Leaf 2.90 %
> Upper stem 2.50 % Lower stem 1.40 %
> Hence a large leaf green puerh can easily have less caffeine than a
> tippy black puerh full of buds. These are facts, Jim, not assumptions
> based upon subjective tastebuds.
>
>
>
> >Caffeine is a stimulant that increases
> >the absorbtion rate of taste. That is the upset empty stomach
> >syndrome. If no caffeine not much tea taste.
>
> Hmm. Please supply a reference for this as I don't buy it.
>
>
> >Gongfu brewing
> >essentially produces a saturated solution of caffeine and taste
> >components which is consistent from infusion to infusion.
>
> Here is where I will be subjective. I brew Gongfu style almost daily,
> and that is a distinct change in the flavor nuances from steep to
> steep. The flavor is not consistent but rather evolves as the steeps
> progress. I have experienced this evolution of flavor from both puerh
> and oolongs almost every time I brew them. The changes in
> concentration between the different notes are definitely NOT linear.
>
> >Otherwise
> >the side effects of caffeine from the first cup would physically
> >interfere with the subsequent tastings. The subtle taste of subsequent
> >infusions can only be delivered by caffeine as a stimulant on the
> >tastebuds.
>
> Huh????? Are you saying I cannot taste subtleties without the presence
> of caffeine? Blasphemy!
>
> >The percentage of caffeine by weight
> >argument in the first infusion doesn't carry much weight when applied
> >to what we experience in the taste of tea. The caffeine by weight in
> >solution is the exception and not the rule.
>
> Seems to me it is a matter of chemistry, and in your case -
> perception.
>
>
>
> > Any statements like caffeine is more
> >soluable than other taste componets is like saying the earth is flat to
> >the horizion for a surveyor. It is a scientific factoid with no
> >meaning to the amount of caffeine in your cup.
>
> Back it up with proof please, and not subjective taste arguments.
> Simply saying it over and over again doesn't make it so.
>
>
> >If the caffeine is gone
> >the taste is gone because the water solution rate is not fundamentally
> >different than the leaching rates of other tasting components.
>
> Hmm, me thinks science proves differently. Solubility of caffeine and
> of tannins is very different.
> This link shows the ratio differences in concentration of tea
> components over time.
> http://carcin.oxfordjournals.org/cgi...ll/24/2/263/T1
> Even as early as 1900 they knew the extraction rates of caffeine and
> tannins were different. This was before we learned of polyphenols and
> the like.
> http://www.ibiblio.org/herbmed/eclec...apter-vii.html
>
>
> >The only reason tea taste different over time is the concentration of
> >solution not the variability of the components. Proportionally they
> >are the same in a weak cup versus a strong cup. The components of the
> >taste are the same only different in concentration. The Gongfu method
> >relies on saturation of all taste components for consistency in taste.
> >The argument that there are fundamentally different dilution rates is a
> >meaningless factoid when applied to taste. Take any tea you want, brew
> >it according to any method you want, and it will essentially taste the
> >same as any other method. The subsequent subtleties argument is
> >nothing more than idiosyncractic personality quirks. The gongfu method
> >can produce more infusions but the taste from a brown betty allowing
> >for volume is the same that is you couldn't tell the difference if
> >blindfolded.
>
> Hmm, here is a quote from a leading journal.
> "About 80% of Cr, Cu, Mn, Ni and Zn and 60% of Fe were in the first
> infusion of a tea" (1)
>
> >Next time don't pick my post
> >apart unless you can reply with more evidence to back up any assertion
> >be it scientific or anecdotal.
>
> Hmm. He who lives in glass houses.......
>
>
> >Don't make
> >me get curt and accuse you of riding my coattails. If you know
> >anything about tea change the subject and start your own thread.
>
> Threatening now, are we?
>
> >It isn't an
> >academic argument perse
>
> That's for sure....
> So let's DO get academic then. All of this highly questionable
> subjectivity is getting boring. Here are some more interesting links
> for those who are interested:
> http://home.netvigator.com/~aa321123/chemistry.html
> http://www.dilmahtea.com/web/faq.asp
> http://itech.pjc.edu/tgrow/2210L/chm2210LCafext.pdf
> http://www.ansinet.org/fulltext/pjbs/pjbs63208-212.pdf
> http://www.centurybio.com.cn/Tea_polyphenols.htm
>
>
>
> References
> (1)
> http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract
> (2) http://www.imperialtea.com/about/FAQ.asp
> (3) http://www.rirdc.gov.au/reports/NPP/04-033.pdf
> See table 2.4- 2.5-4.1
>
>
>
>
>
>
> Mike Petro
> http://www.pu-erh.net
> "In this work, when it shall be found that much is omitted, let it not be forgotten that much likewise is performed."
> Samuel Johnson, 1775, upon finishing his dictionary.