On Mar 2, 9:12*am, corax wrote:
[slippy] where again is the link to the study that says it takes much
longer to get out the caffeine? *Couldn't find it from before. *thx

[shen] Nigel! Nigel! Where are you, Nigel?? It's the old caffeine
sticky mess again...................we need you!

[corax] at the moment nigel is, i believe, trotting the globe once
again, but his latest summation of the evidence on caffeine levels in
tea -- and common misperceptions about decaffeinating tea -- is
conveniently located [with some new material added as well] for all to
read at CHA DAO. this [permanent] short link will whisk you thither in
a trice:

http://tinyurl.com/2kgwy4

there is already a whole string of comments there, too, which make
interesting reading, and to which readers are invited to contribute.

Thank you, Corax. My dear old mind plays tricks on me and I forgot
(geez...how could I?) about that wonderful piece in Cha Dao.
Me thinks I am caffeine deprived!
Shen

On Mar 2, 1:00 am, Alan wrote:
Tea People,

I just watched the "Caffeinated" episode of Unwrapped on the Food
Nework. The master blender (or taster or whatever his title was) at
Lipton said that a 15-20 second steep will SIGNIFICANTLY reduce the
caffeine levels of subsequent steeps. ARGH!!!!

Thanks. I just had to vent.

Alan

Hello to scientific tea lovers.

Tea brew , basically , is a complex mixture of so many dissolved
chemicals ( which were initially present in the tea leaf ) in water ,
besides the chemicals present in water used . So the resultant tea
brew depends upon the
* Quantity, Quality and temperature of water used
* Quantity and Quality of tea used.
* The brewing process ( time of brewing etc) used
* and the solubility of the chemicals present in tea.
Solubility of different compounds in tea leaf in boiling water .
decreases as we go down below the following list of compounds.-
1. Carbohydrates
2. Salts and Organic acids
3. Polyphenols
4. Proteins
5. Caffeine
6. Flavor compounds
As is clear from the above list, solubility of carbohydrates is
maximum and of flavor compounds is minimum..
The following are the further details regarding solubility of the
above
1. Carbohydratres- in tea are in the following forms. And their
solubility is less as we go down the list.
A. Free Carbohydrates- glucose etc- readily soluble in water.
B. Pectins- . Less soluble than free Carbohydrates. They are smaller
in size than hemicellulose They form a jelly. Precipitation occurs
when cooled down. Their solubility increases with rise in
temperature .
C. Hemicellulose- more soluble than starch. Solubility increases with
temperature.
D. Starch- Solubilty depends upon temperature
E. Cellulose not soluble in water.
2. Salts and Organic acids
Salts and Organic acids are taken from the soil by the tea
plant .Salts are taken in the form of Nitrates,chlorides, etc of
Calcium, Magnesium, Sodium , and Potassium etc . Salts are more
soluble in comparision to the base materials.
3. Polyphenols- Solubility dcreases with polymerization and increases
with rise in temperature.
4. Proteins- the solubility of proteins increases with rise in
temperature but after a particular temperature the solubility
decreases with temperature due to coagulation.
5. Caffeine- solubility increases with temperature.
6. Flavor compounds- least soluble

Caffeine gives bitter taste and I have never found a bitter taste in
first 15- 20 second steep in any tea tasted by me and I found them
rather sweet since it contained maximum percentage of sweet
carbohydrates). So "Lipton said that a 15-20 second steep will
SIGNIFICANTLY reduce the caffeine levels of subsequent steeps" is
unscientific. Scientific part of my mind tells me that people
interested in less caffeine should prefer ist steep of 15-20 seconds,
in comparision to later steeps.

S.M.Changoiwala
Gopaldhara tea Company Pvt Ltd.
India.