Will aging removes pesticide?
Assume that the Pu's leave has got pesticide. Will aging remove/reduce the effect?
Re: Will aging removes pesticide?
It depends on the pesticide. Did you have any in mind?
For example, the Wikipedia entry for DDT says that its soil half-life is 22 days to 30 years (and a half-life is the time for half of the sample to vanish). The large range exists likely due to the environmental conditions -- exposure to sun and rain, oxidation, or maybe bacteria that prefer to munch on chlorinated hydrocarbons (bio-degradation).
So in aging your pu, it's not clear how much the bio-degradation would deplete that particular pesticide...
If you have any pesticides of interest, just track down some info on them (including their MSDS) and look for something that amounts to shelf life... that would be the a good starting point.
For example, the Wikipedia entry for DDT says that its soil half-life is 22 days to 30 years (and a half-life is the time for half of the sample to vanish). The large range exists likely due to the environmental conditions -- exposure to sun and rain, oxidation, or maybe bacteria that prefer to munch on chlorinated hydrocarbons (bio-degradation).
So in aging your pu, it's not clear how much the bio-degradation would deplete that particular pesticide...
If you have any pesticides of interest, just track down some info on them (including their MSDS) and look for something that amounts to shelf life... that would be the a good starting point.
Nov 20th, '10, 11:37
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Re: Will aging removes pesticide?
Most pesticides allowed to be used degrade in few weeks. In this sense, even unaged tea is safer than most fruits and vegetables. But this may not mean all the negative impacts can be removed.
Re: Will aging removes pesticide?
This may be true today in the US, but is it true today in China? I ask because I do not know.gingkoseto wrote:Most pesticides allowed to be used degrade in few weeks.
Also remember that those old bits of pu that come from the 60s and 80s. What was used in China then? Again, I do not know.
Nov 20th, '10, 13:01
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Re: Will aging removes pesticide?
If consider "allowed to be used by laws", I believe this is true world wide. But then there are cases that people use pesticides that are not supposed to be used.Drax wrote:This may be true today in the US, but is it true today in China? I ask because I do not know.gingkoseto wrote:Most pesticides allowed to be used degrade in few weeks.
Also remember that those old bits of pu that come from the 60s and 80s. What was used in China then? Again, I do not know.
On the one hand, lack of education and short-sightedness drive some people to use illegal pesticide or use illegal amount. On the other hand, in developing countries, pesticides are not as affordable as in industrialized countries and agriculture is less industrialized in developing countries. This actually holds people back from using pesticides. But sadly developing countries envy the success of "green revolution" in developed countries and dream of getting industrialized.
The 60s pu is supposed to be pesticide free. It was the good old days when pesticides were not known or affordable by farmers. I am not sure of 80s. But it's possible that many 80s pu products are pesticide free. Many regions in China were still too remote to get access to a lot of pesticides by early 80s. Yunnan is one of the most remote provinces in China. Besides, before the puerh madness starting from late 90s, there wasn't this urge or greed to produce a lot of puerh.
But the 60s and 80s are gone. As for today, the classic interprets it all --
It is the best of times, it is the worst of times, it is the age of wisdom, it is the age of foolishness...