worried about pesticides in tea?

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

Thanks.

Phyll

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

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.

Julian

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

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).

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

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.

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.

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

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

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

I'd be really interested to see a translation (non babelfish / google translator translation) of this thread on San Zui:

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.

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.

hi phyll,

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

ankit

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

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..

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

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

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.

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

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 here: