24 Feb 2020, 02:55
(23 Feb 2020, 10:05 )no smile Wrote: [ -> ]bought from a local store making their own teaYou mean they make their own "blend/mix", not "tea", I guess.
(23 Feb 2020, 10:05 )no smile Wrote: [ -> ]I'm now on bio tea only (well, almost)The word "bio" always puzzles me. I remember one woman in the garden store asked for "biological dung". When the seller asked what she meant by "biological dung", the answer was "The dung that is ... well.... biological...". 😁
Sounds funny. But recent conversations and discussions with my mother and children, who taught me to get the information directly from the sources (published scientific articles), led me to investigating the question a bit deeper, than checking reddit and quora 😉
Indeed, tea plantations use herbicides and pesticides. (I do not have to guess now, I have analysis results in front of me). Indeed, in some cases the amount of residuals can be higher, that the recommended level. Two questions: how can you trust the eco labels, and what can you do.
I can't answer the former, but here's some tips for the latter:
Rinsing Tea before Brewing Decreases Pesticide Residues in Tea Infusion. ( https://www.ncbi.nlm.nih.gov/pubmed/30350971 ). This is how the Oolongs, Pu Er's and some other Chinese teas are supposed to be brewed, according to the Chinese traditions and recommendations. This is what the study says:
Quote:Rinsing dried tea leaves before brewing is a traditional way of preparing rolled oolong tea in China. This study analyzes how rinsing green, black, and oolong tea before brewing affects the levels of pesticide residues in the tea infusion. Eight representative insecticides of different polarities were tracked, namely, three neonicotinoids (acetamiprid, imidacloprid, and thiamethoxam), two organophosphates (dimethoate and malathion), and three pyrethroids (bifenthrin, β-cypermethrin, and fenvalerate). The results showed that the eight pesticides transferred into the rinse water at rates between 0.2 and 24% after 5, 10, 20, or 30 s. Rinsing tea before brewing reduced the pesticide risk levels by 5-59% in the tea infusion. Five functional components, such as epigallocatechin gallate and caffeine, were reduced by 0-11% in the tea infusion. The results can be used to develop an effective method of rinsing tea before brewing that reduces pesticide exposure risks.
So, this one is answered. Next question, should you infuse or boil:
Residues and contaminants in tea and tea infusions. https://www.researchgate.net/publication..._infusions
Quote:Consumers are very aware of contaminants that could pose potential health hazards. Most people drink tea as an infusion (adding hot water); however, in some countries, including India, China, and Egypt tea is drunk as a decoction (tea and water are boiled together). An infusion usually brings the soluble ingredients into solution; whereas a decoction brings all soluble and non-soluble constituents together. Therefore, a cup of tea may contain various kinds of contaminants. In this review, we focus on green and black tea, because they are most commonly consumed. Our target was to examine the transfer rate of contaminants (pesticides, environmental pollutants, mycotoxins, microorganisms, toxic heavy metals, radioactive isotopes (radionuclides), and plant growth regulators) from tea to infusion/brewing, factors contributing to the transfer potential and contaminants degradation, and residues in or on the spent leaves. We concluded that most contaminants leaching into tea infusion are not detected or are detected at a level lower than the regulatory limits.However, the traditional practice of over-boiling tea leaves should be discouraged, as there may be a chance for more transfer of contaminants from the tea to the brew.
This one is answered as well.
TL;DR: drink Chinese Oolong and Pu'Er teas by rinsing them first in boiling water, and then infuse 😊