Tea (rec.drink.tea) Discussion relating to tea, the world's second most consumed beverage (after water), made by infusing or boiling the leaves of the tea plant (C. sinensis or close relatives) in water.

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Old 21-09-2007, 01:57 AM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

On Sep 20, 8:10 am, Ankit Lochan wrote:
On Sep 20, 3:12 am, juliantai wrote:

easier option - send the samples to me - i will have them tested at
1/10th the price, i guess.


Ankit, I will be more than happy to send it to you, if you don't mind
the hassle.


What kinds of chemicals do you screen for? I have in my mind lead,
fluoride, aluminun (not sure why) and pesticides.


We can potentially collate the information in one big database to
share the results between the tea community.


Julianhttp://www.amazing-green-tea.com


hi julian,

normally we do

moisture content
crude fibre
water extract
ash content
tannic acid
stem content
water soluble alkalinity
water soluble ash
caffeeine content
acid insoluble ash
any essence or additional colors
any foreign matter
mettalic matter
tea used before
reducing polyphenols
yeast and mould
E.coli
coliform
any pollution fungi
any pollution of mushrooms
pesticide residue of
diazinon
melathion
fenamiphos
propargite
heavy metals
lead
copper
arsenic
nickel

we can also do anything additional you want.

expenses on us - dont bother - feel free to send the samples - we can
share the results with everyone.. people can know what they are
drinking.....


Ankit,
I would also like to have some tea tested. Every year I get a few
pounds of high mountain oolong from Taiwan. I agree that you should
pass through your costs for this though. I'd hate for you to have to
absorb that. You might be inundated with teas! Also do you test for
DDT?
Bob


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Old 21-09-2007, 09:48 AM posted to rec.food.drink.tea
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On Sep 21, 12:42 am, juliantai wrote:
Ankit
Your list is very comprehensive. I suppose your heavymetal will
include fluoride? A lot of my visitors are interested in this
contaminant.


Let's retain a sense of balance here - fluoride is naturally present
in tea and is not a contaminant (neither is it a heavy metal).


I am really excited - putting these great tasting teas to an objective
test! Can pollutants and high grades exist hand in hand? I am
intrigued!


Of the 30 items Ankit Lochan lists for analysis it would be impossible
(in the real world) to have zero presence for at least 29 of them -
then at what positive level of presence do you define 'pollution'?
And is your level the same as my level?

Nigel at Teacraft


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Old 21-09-2007, 03:07 PM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

moisture content
crude fibre
water extract
ash content
tannic acid
stem content
water soluble alkalinity
water soluble ash
caffeeine content
acid insoluble ash
any essence or additional colors
any foreign matter
mettalic matter
tea used before
reducing polyphenols
yeast and mould
E.coli
coliform
any pollution fungi
any pollution of mushrooms


Okay, all of the above can be done with fairly simple kitchen-grade
equipment. It's mostly microscopic examination, an ash burn test,
some cultures, and simple titration for the polyphenyls, tannic acid,
pH, and caffine.


pesticide residue of
diazinon
melathion
fenamiphos
propargite


Now, these are the hard ones. My question is whether you are doing
these by titration, or by HPLC. If you have an HPLC apparatus, you can
do a huge variety of other screens for things like DDT and just about
any other substance if you know to look for it.

The HPLC trace also is very interesting as a qualitative indication that
can help show contamination... when you see a very narrow spike it's time
to find out what it is.

heavy metals
lead
copper
arsenic
nickel


All of these are also easy to do by titration, although if you have an
HPLC machine you can avoid the labour.

There are also some other lighter metals that can get concentrated
by plants, which are worth looking at. (Again, if you have an HPLC rig
it's easy to do lots of tests on one sample with no additional labour,
so there is motivation to do so).

Many of the larger whiskey distilleries are now using chromatography
systems in order to get a better handle on batch-to-batch variations,
and have done some research into some of the more significant flavour
constitutents of whiskey. It would be very impressive to see some
of the tea blending folks doing that.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Old 21-09-2007, 08:27 PM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

Phyll, it's noble of you to volunteer to hand over some precious '50s
Pu'er. But, unless you're rich enough to drink that stuff often,
wouldn't it make more sense to test some everyday teas? I mean, this
is about health, no?

/Lew
---
Lew Perin /
recently updated: Fenghuang Dancong


Good point. It was an academic curiosity on my part. I am curious to
find out if DDT or other banned substance is in older teas, which
command high prices for being collectible. I don't have much of old
teas, but if it takes a few milligrams (like in the CSI), then it's
not prohibitive.

Phyll

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Old 21-09-2007, 08:33 PM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

Of the 30 items Ankit Lochan lists for analysis it would be impossible
(in the real world) to have zero presence for at least 29 of them -
then at what positive level of presence do you define 'pollution'?
And is your level the same as my level?

Nigel at Teacraft


Wouldn't the test show what a the upper limit is in ppm or other unit
measurement? Anything above a certain threshold is a red flag...like
my cholesterol level.

Phyll



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Old 22-09-2007, 02:57 AM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

I'd be really interested to see a translation (non babelfish / google
translator translation) of this thread on San Zui:
http://sanzui.com/bbs/showthread.php?t=76279
if anyone has the time / inclination.

w

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Old 23-09-2007, 04:46 AM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

Xiamen is a festering cesspool under a tourist-friendly guise; Fuzhou
is just as filthy.


Xiamen is actually a very pretty city, almost on par with Hong Kong;
except Hong Kong is way more crowded than Xiamen. But yeah, the air in
Fuzhou is pretty darn dirty. I always have a cough every time I go
there. Near Fuzhou, there is a town called Fuding, where they produce
white tea. Fuzhou has a lot of good eats there. Really delicious
stuff. Xiamen has some good food too. Lots of seafood - but probably
all polluted. Anyway, it tastes good.

I would be willing to bet all the money in my savings account, which
ain't much, folks, that any random sample of tea from Taizhong (where
most wulong is produced in Taiwan), a relatively mountainous, clean
place, would have a better sanitary rating than ANY TEA, INCLUDING THE
HIGHEST GRADE, from Fujian AnXi (where Tieguan, the most famous tea
from Fujian) is produced. I'd also be willing to bet that the Rock
teas from WuYi Mountain would have the same rating of pollution as in
Anxi.


Well, Anxi, comparatively speaking is pretty filthy. You can't argue
that. That's the town proper - is pretty dirty and grimy and stinky.
The food there is not so great either. But Tieguanyin is also grown in
the smaller towns in the mountains around there. So it would probably
be cleaner than the stuff that they grow nearest the town.

But Wuyi is clean everywhere - the town is clean, the mountains are
clean, the roadsides are clean. Everywhere is very clean. Much cleaner
than Anxi. So I bet teas from Wuyi are much cleaner than those from
Anxi. But like I said, pollution can travel on the wind and rain. What
goes up in one place may not necessarily pollute in the same area. And
I bet a lot of pollution from Mainland China gets blown over to
Taiwan. They're just too close in proximity to not be affected.

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Old 23-09-2007, 10:18 AM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

On Sep 21, 2:30 am, Phyll wrote:
On Sep 20, 5:10 am, Ankit Lochan wrote:





On Sep 20, 3:12 am, juliantai wrote:


easier option - send the samples to me - i will have them tested at
1/10th the price, i guess.


Ankit, I will be more than happy to send it to you, if you don't mind
the hassle.


What kinds of chemicals do you screen for? I have in my mind lead,
fluoride, aluminun (not sure why) and pesticides.


We can potentially collate the information in one big database to
share the results between the tea community.


Julianhttp://www.amazing-green-tea.com


hi julian,


normally we do


moisture content
crude fibre
water extract
ash content
tannic acid
stem content
water soluble alkalinity
water soluble ash
caffeeine content
acid insoluble ash
any essence or additional colors
any foreign matter
mettalic matter
tea used before
reducing polyphenols
yeast and mould
E.coli
coliform
any pollution fungi
any pollution of mushrooms
pesticide residue of
diazinon
melathion
fenamiphos
propargite
heavy metals
lead
copper
arsenic
nickel


we can also do anything additional you want.


expenses on us - dont bother - feel free to send the samples - we can
share the results with everyone.. people can know what they are
drinking.....


Ankit,

How much sample do you need to analyze the checimal make up of a tea?
I am tempted to have some of the older pu'er analyzed...stuff from the
1950's onwards. Would be interesting to find out what they contain.

Thanks.

Phyll- Hide quoted text -

- Show quoted text -


hi phyll,

for the tests to be performed the lab requires at least 250g sample..

ankit

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Old 23-09-2007, 10:19 AM posted to rec.food.drink.tea
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On Sep 21, 2:59 am, Lewis Perin wrote:
Phyll writes:
On Sep 20, 5:10 am, Ankit Lochan wrote:
[...lots of things he'll test for...]
we can also do anything additional you want.


expenses on us - dont bother - feel free to send the samples - we can
share the results with everyone.. people can know what they are
drinking.....


Ankit,


How much sample do you need to analyze the checimal make up of a tea?
I am tempted to have some of the older pu'er analyzed...stuff from the
1950's onwards. Would be interesting to find out what they contain.


Phyll, it's noble of you to volunteer to hand over some precious '50s
Pu'er. But, unless you're rich enough to drink that stuff often,
wouldn't it make more sense to test some everyday teas? I mean, this
is about health, no?

/Lew
---
Lew Perin /
recently updated: Fenghuang Dancong


such expensive and rare puerhs - i think phyll needs to think it
over again as the quantity required is really high...

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Old 23-09-2007, 10:22 AM posted to rec.food.drink.tea
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On Sep 21, 4:42 am, juliantai wrote:
Ankit

It is really too kind of you. I suggest you charge some fees, i don't
really want to see you inundated with requests and taking too much of
your time.

Your list is very comprehensive. I suppose your heavymetal will
include fluoride? A lot of my visitors are interested in this
contaminant.

I will be happy to ship a green tea to you, and another oolong tea
that I am considering working with later this year.

How much sample do you need? I will happy to email to get the details
later this year (after the October oolong tea harvest).

I am really excited - putting these great tasting teas to an objective
test! Can pollutants and high grades exist hand in hand? I am
intrigued!

As a special thank you, I will also send you some secret presents.

Julianhttp://www.amazing-green-tea.com


hi julian,

i am sorry for not replying earlier - i was in kolkata for some imp.
meetings - just got back today..

we can include fluoride.. not a problem..

dont worry about the charges - we can talk on that later once the
tests are done.

minimum quantity of 250g is needed for us to perform all the required
tests.

thanks you for the secret presents - you are really very kind -
appreciated with folded hands..



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Old 23-09-2007, 10:23 AM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

On Sep 21, 5:57 am, wrote:
On Sep 20, 8:10 am, Ankit Lochan wrote:





On Sep 20, 3:12 am, juliantai wrote:


easier option - send the samples to me - i will have them tested at
1/10th the price, i guess.


Ankit, I will be more than happy to send it to you, if you don't mind
the hassle.


What kinds of chemicals do you screen for? I have in my mind lead,
fluoride, aluminun (not sure why) and pesticides.


We can potentially collate the information in one big database to
share the results between the tea community.


Julianhttp://www.amazing-green-tea.com


hi julian,


normally we do


moisture content
crude fibre
water extract
ash content
tannic acid
stem content
water soluble alkalinity
water soluble ash
caffeeine content
acid insoluble ash
any essence or additional colors
any foreign matter
mettalic matter
tea used before
reducing polyphenols
yeast and mould
E.coli
coliform
any pollution fungi
any pollution of mushrooms
pesticide residue of
diazinon
melathion
fenamiphos
propargite
heavy metals
lead
copper
arsenic
nickel


we can also do anything additional you want.


expenses on us - dont bother - feel free to send the samples - we can
share the results with everyone.. people can know what they are
drinking.....


Ankit,
I would also like to have some tea tested. Every year I get a few
pounds of high mountain oolong from Taiwan. I agree that you should
pass through your costs for this though. I'd hate for you to have to
absorb that. You might be inundated with teas! Also do you test for
DDT?
Bob- Hide quoted text -

- Show quoted text -


please feel free to send samples of the teas you want us to organise
tests off.

we can include tests for DDT - not a problem..

do not worry on the charges - we can talk of that later once the work
is done..

regards

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Old 23-09-2007, 10:25 AM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

On Sep 21, 1:48 pm, Nigel wrote:
On Sep 21, 12:42 am, juliantai wrote:

Ankit
Your list is very comprehensive. I suppose your heavymetal will
include fluoride? A lot of my visitors are interested in this
contaminant.


Let's retain a sense of balance here - fluoride is naturally present
in tea and is not a contaminant (neither is it a heavy metal).



I am really excited - putting these great tasting teas to an objective
test! Can pollutants and high grades exist hand in hand? I am
intrigued!


Of the 30 items Ankit Lochan lists for analysis it would be impossible
(in the real world) to have zero presence for at least 29 of them -
then at what positive level of presence do you define 'pollution'?
And is your level the same as my level?

Nigel at Teacraft


EU norms allow a certain % - normally teas are within that range.. if
that is the case we can consider the tea fit... my opinion - i think
this can be done - please correct me if i am wrong.

regards

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Old 23-09-2007, 11:41 AM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

But Wuyi is clean everywhere - the town is clean, the mountains are
clean, the roadsides are clean. Everywhere is very clean. Much cleaner
than Anxi. So I bet teas from Wuyi are much cleaner than those from
Anxi. But like I said, pollution can travel on the wind and rain. What
goes up in one place may not necessarily pollute in the same area. And
I bet a lot of pollution from Mainland China gets blown over to
Taiwan. They're just too close in proximity to not be affected.


I'm not so much talking about the pollution factor; I'm talking more
about the pesticides that are used. The environmental pollution is
just something we have to deal with but the man-made pollution that
the farmers create in the form of chemicals applied directly to the
teas to up their stock is more worrisome. The latter can and should
be controlled but it is not; it will never be.

It was a merchant, a local of XiPing (one of the big producers of TGY
besides GanDe) that told me to stop drinking his tea and Wulong from
Fujian.

Taiwan has and does follow standards related to pesticides/
insecticides with their teas, all exports, and even domestic goods.
China does not.

So, who you more willing to believe even without getting into stats?
China or Taiwan? I'm with the latter.

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Old 23-09-2007, 02:24 PM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

Phyll wrote:
Of the 30 items Ankit Lochan lists for analysis it would be impossible
(in the real world) to have zero presence for at least 29 of them -
then at what positive level of presence do you define 'pollution'?
And is your level the same as my level?


Wouldn't the test show what a the upper limit is in ppm or other unit
measurement? Anything above a certain threshold is a red flag...like
my cholesterol level.


Right, but the point is where that threshold is set. Where I think it
should be set may not be the same place where you care to set it.

In some cases, the tests don't tell everything. For example, if you do
a typical test for a heavy metal, it cannot distinguish between soluble
salts which are very bad, and insoluble salts which are much less harmful.
So where you decide to put the threshold requires making some assumptions
about the composition in the first place.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Old 23-09-2007, 04:13 PM posted to rec.food.drink.tea
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Default worried about pesticides in tea?

Oh, the pollution issues are still there. But the farming practices are
better-regulated at least.


There's another point I should mention. Many Taiwanese businesspeople
come to Fujian and invest in Fujian. So they might set up tea farms
and grow Taiwan tea - right in Fujian. The same for Fujian tea farmers
and entrepreneurs - they will find some suitable and cheap land, and
start tea cultivation. So the so-called Taiwan tea you drink may not
even be from Taiwan.


There's an article he
http://www.teafromtaiwan.com/Taiwan_...n_in_China.htm




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