Sunday, February 2, 2020

Going live on twitch.tv/vul100!!! Here are some answers to FAQ's

On February 5th 2020 I'll be going live on twitch.tv/vul100!  Here are answers to questions you may have:

What is twitch.tv?

— Twitch.tv is a service for live streaming. Live streaming is a way of broadcasting live video over the internet, and of recording the broadcast so that people can watch later. You will be able to watch my channel by going to twitch.tv/vul100.

What will you do on twitch.tv/vul100?

—I’ll be talking, demonstrating, carrying out experiments, interviewing, and best of all, chatting with you. 

It’ll mostly be about tea, but we can chat about coffee, wine, beer, and food, and all manner of things that have caught our attention. 

What will I see when I go to twitch.tv/vul100?

—Here's how the screen is laid out and what you can do:



When will you be broadcasting on twitch.tv/vul100?

—Monday and Wednesday at 9pm Eastern Standard Time US, starting Wednesday February 5th.

How long will the broadcasts last?

—About an hour…depends on what we do and what questions you have.

Do I need anything special to watch twitch.tv/vul100?

— You can watch twitch.tv/vul100 on any platform and device that has access to the internet.

If you want to chat, though, you need to sign up.

How do I sign up?
Go to https://www.twitch.tv and select the "Sign up" button on the top-right portion of the page. This will open the Log In / Sign Up screen. To sign up for a new account on Twitch, fill out the “Sign Up” form. 
When you sign up you choose a nickname that you will use for chatting—and you will also be able to create your own twitch channel using the nickname! 

Why vul100 and not pairteas?

vul100 is the nickname I chose when I first signed up for twitch.tv so I could watch my daughter and other friends. 

Can I support twitch.tv/vul100?

—Yes!  The key is to become a follower—then you will receive a link via email for joining the broadcast each time I go live.

Further, Twitch.tv allows you to become a subscriber for a small fee of each month. As a subscriber, you will be able to ditch the pesky ads that play whenever you sign in to a live broadcast—it’s these ads that support the twitch.tv infrastructure. By subscribing you will continue supporting the infrastructure while it may also give me a small amount to support tea purchases and tea-related charities, etc. To find out more, go to:



===>>> So eager to get together with you on twitch.tv/vul100! <<<===

Thursday, January 30, 2020

“The Aromas of Wine and Tea: a Sensory Adventure!” at the Global Tea Initiative, January 17 2020.

Note: all photos in this post are courtesy of Yan Chen, Yan Chen, Professor, Louisiana State University Agricultural Center Hammond Research Station.

Such fun to give the talk “The Aromas of Wine and Tea: a Sensory Adventure!”  with the help of Marzi Pecen. Here we are talking with attendees before the start—Marzi is standing on the right:



In the Sensory Theater of the Robert Mondavi Institute for Wine and Food Science we could have a true sensory adventure—we could experience directly how the aromas of wine and tea shift and change as we alternatively sniffed individual chemicals and the teas and wines.

Here’s a picture of the set-up:




In front of each participant were six cups (the wine glasses in the back were in place for Andrew Waterhouse’s talk about wine aging, that followed my talk). 

The three cups in front held (left to right) a green, oolong, and black tea, all Ready-to-Drink from Ito-En—thank you so much Rona Tison of Ito-En for providing these. The three cups behind the tea cups held a Chardonnay, a Pinto Noir, and a Cabernet Sauvignon, all from Robert Mondavi — many thanks to Babette Orendain of the Institute for the wines, and to her and her UC Davis student helpers for setting out everything!

(fBTW, the green tea was very close in color to the oolong—it was pan-fired—but it was clearly green tea by its aroma).

Earlier in the day, Colloquium speaker Susan Eberle, Professor (Chemist) of Viticulture and Enology, and Associate Dean, Undergraduate Academic Programs, College of Agricultural and Environmental Sciences at University of California Davis, had described some of the aroma chemicals common to tea and wine. Here is a picture of one of her slides:




To my great delight, I had chosen compounds that corresponded to these categories for my demonstration. I was planning to touch on all of these categories, but time was running short (we had to start late) so I chose just three:
  • 2-phenylethanol, a phenylpropanoid, 
  • β-damascenone, a C13-norisoprenoid,
  • vanillin—note that vanillin is developed during the heating steps in tea and comes from the oak barrels for wine., so is not actually either in the grape or the fresh leaf to any extent.
We started by soaking perfume blotter paddles ("touches") then sniffing 2-phenylethanol and β-damascenone separately and then together. When we sniff them together our olfactory bulb joins them together as "odor objects" different from the two separate smells. For me and for many of the participants, the resulting odor object was "honey." However, people differ genetically in their ability to smell β-damascenone, so the "honey" effect was less pronounced for some. This observation allowed for a very short comment on the genetic ability to smell different aromas in teas and wines.

The next effect we experienced was masking. People first sniffed the Cabernet Sauvignon, then sniffed the 2-phenylethanol or the β-damascenone, then sniffed the wine again—the smell of the wine disappeared! The same held for the black tea. Neither the wine nor the tea has a significant amount of these compounds so, at the concentrations on the perfume paddles, these chemicals effectively masked the other aromas in the tea and wine.

By contrast, when we carried out the same experiment with the Pinot Noir and the Oolong, the aromas of each became richer and even more pleasant. This wine and this tea both have significant amounts of these chemicals; sniffing the paddles before sniffing the wine and tea brought out their aromas—an additive effect.

Vanillin is produced when oak barrels are fired, so oaked wines will have a lot of vanillin. The Chardonnay we had was only lightly oaked, so when sniffed alone if had a more fruity, less Chardonnay-like aroma that wasn't as pleasant as that of a more oaked wine would be—Andrew Waterhouse (Director of the Mondavi Institute) and I agreed that the wine had probably been treated with oak chips rather than been aged in a barrel. When you sniffed the wine after sniffing the vanillin, the aroma of the wine improved dramatically. 

Black tea is heated and fully oxidized, so it too contains significant quantities of vanillin, from the breakdown of lignin in the leaf's veins. Just as we experienced with the Chardonnay, the aroma of the black tea became richer after we had sniffed the vanillin. Interestingly, the vanillin somehow incorporated itself into the overall tea aroma, rather than stand out as separate but compatible as it did with the Chardonnay—with the black tea we were again experiencing odor object formation, which could be described simply as "black tea."

By contrast none of these compounds are present in green tea, so sniffing them before sniffing the green tea made the green tea either smell awful (for me) or just loose character completely (for some other people).

BTW, you can carry out some of these experiments at home with household herbs and spices. Will be live streaming to show how these experiments work on my upcoming twitch.tv channel. Details and link to come!

Or you could get samples of the actual chemicals in a Scents of Tea kit at http://scentsoftea.com and carry out the experiments with all manner of scents, wines, and teas.

==>> Now available on Amazon: Tea: a Nerd's Eye View.















Thursday, January 23, 2020

5th Annual Colloquium of The Global Tea Initiative at UC Davis

Such fun at the 5th Annual Colloquium of the Global Tea Initiative—“Tea & Wine - The Great Debate”—at UC Davis under the leadership of Katharine Burnett!




Some highlights:
  • People who know me know that I am not really fond of puer…but I was entranced by the dialog between Roy Fong of The Imperial Tea Court in San Francisco (https://www.imperialtea.com/Default.asp), and James Norwood Pratt, tea writer and connoisseur (https://jamesnorwoodpratt.com). Norwood asked the questions and Roy answered, all about how Roy produces his puers in his warehouse in San Francisco. He imports his raw maocha from China, then with a practiced eye for temperature and humidity at different levels in his warehouse, he moves his bings around to perfect them, for years and more years. It was an extraordinarily warm and friendly conversation that highlighted the cordiality that I find so refreshing in “tea people.” Am looking forward to a possible video of another dialog between these two, that my friend Marzi Pecen hopes to get off the ground.

  • One persistent theme of the Colloquium was climate change and its effects on both wine and tea. The point about tea was forcefully brought out by Fitrio Ashardiono, Ph.D., Senior Researcher, Asia- Japan Research Institute, Ritsumeikan University, and UCD Visiting Scholar. His talk was entitled Tea Cultivation and Terroir Framework: Developing the Terroir Concept for the Tea Industry, but really focussed on how climate change would affect tea growing in Uji Japan—the home of exquisite matcha—and what structural issues would affect the growers’ responses.  It’s clear that the problems will be difficult to solve, but equally clear that we must solve them. (It was in the 70’s in Boston in January, only a few days earlier!)
Fitrio displayed a picture similar to this one, showing that tea growing in Uji occurs in the middle  of an urban environment, complicating the conditions for growing tea.
Photo by Arboramo, Wikipedia CC BY-SA 4.0.
  • Of course, UC Davis is famed for its Viticulture & Enology Program, so we were guaranteed some super interesting information about wines. In particular, learned from Ron Runnebaum, Assistant Professor, Viticulture and Enology, UC Davis, about one of my favorite wines, Pinot Noir, and the effects of growing the wine in different places on the West Coast. Thoroughly nerded out on all the graphs and Principle Component Analyses—when I was at Cornell, had huge discussions with my graduate students about how to analyze our data—do you use Principle Component Analysis or Factor Analysis or neither? And how do you interpret the results?  Was thrilled to see some of my favorite tea scents mentioned on the graphs—scents that I used in my talk.

Day 2 was Sensory Day, introduced by Andrew L. Waterhouse, Director of the Robert Mondavi Institute of Wine and Food Science. Was especially glad to have met him—so very much appreciated his kindness as well as his knowledge.  
  • Al Robbat, Director/Professor Chemistry Department Sensory and Science Center and Center for Field Analytical Studies & Technology at Tufts, and inventor of the most complex and effective systems for analyzing aroma chemicals ever, again brought home the effects of climate change on tea and tea quality. With his systems, you can clearly see what changes in monsoon patterns, for example, cause in tea chemistry. Have to look more deeply into this question for another blog post!


  • So grateful to Sue Ebeler, Professor, Viticulture and Enology and Associate Dean, Undergraduate Academic Programs, College of Agricultural and Environmental Science at UC Davis, who provided a superb introduction for my experiential adventure that was to come later in the afternoon—she described many of the aromas I was planning to provide, and where they come from in wine and tea. 
  • Nikolai Kuhnert, Professor Analytical Chemistry Jacobs University Bremen, Germany also had me nerding out with his talk about tannins entitled High Resolution Analysis of Black Tea and Wine. Nikolai was another of the kind thoughtful people I met at the conference—I can’t say it enough, the people at the Colloquium were people I am proud to be among.
  • And Jonathan Cave, Treasury Wine Estates (https://www.tweglobal.com), who talked about tannins in wine, and reminded me of how anthocyanins alter the flavor profile of wines enough so that when added to white wine, people may become confused and think it might be red.
  • Then it was my turn. I was fortunate to be able to give my talk at the Robert Mondavi Institute Sensory Theater, where people sat at desks in an amphitheater, with wines and teas arrayed in front of them. Rona Tison of Ito-En (https://itoen.com) provided three ready-to-drink teas, green, oolong, and black, and Mondavi provided a Chardonnay, a Pinot Noir, and a Cabernet. With the expert assistance of my friend Marzi Pecen (she is not only a tea specialist, but a parfumeuse) we handed out paddles/touches with scents on them, and had fun making the aromas of the teas and wines disappear and reappear. More about how this works in my next blogpost.
  • Finally, after me came Andrew Waterhouse, with three Cabernet Sauvignons that were so different it boggled the mind. Three different ages, three completely different flavor profiles. Andy talked about what aging does to wine profiles, and neatly summed up what we had heard throughout the colloquium: sensory matters!
One more experience, so exquisite!  Susumu Yotsukawa, designer, www.kisendo.net, brought a collection of wine/sake and tea items to savor with our eyes. Here's one:

sake cup designed by Susumu Yotsukawa
A sake cup designed by Susumu Yotsukawa, made of Japanese cherry birch and brass,​ available at https://www.woahjapan.com/product.asp?shocd=WJC00329

Go to the Kisendo website—www.kisendo.net—for more on which to feast your eyes!


==>> Available on Amazon in paperback, my latest book, "Tea: a Nerd's Eye View."











Saturday, November 9, 2019

Tea serving temperature

Yet another except from my upcoming book: Tea: a Nerd's Eye View.

Tea serving temperature
Fun question: at what temperature to serve tea? 
The first systematic study I found to answer this question was provided by Ragita Pramudya and Han-Seok Seo, which studied liking and emotional response to coffee and green tea.*
They used bagged pan-fired Korean green tea which can be expected to have a roasted flavor. They prepared the tea by brewing the bags with boiling water for 5 minutes. Under these conditions they had a greater chance of leaching out indole with its animalic quality, and catechins, with their bitterness. They then served the tea at 5ºC/41ºF, 25ºC/77ºF, and 65ºC/149ºF. I’ve graphed their results for the proportion of participants attributing each quality to the teas here:


As you can see, more people assigned potentially unpleasant qualities to the tea served at 5ºC than to the tea served at 65ºC, and more people assigned positive qualities to the tea served at 65ºG than at 5ºC. The tea served at (more or less) room temperature had intermediate qualities. 
Pungency is the term used to describe the sensations induced by activation of the cold trigeminal receptor TRPA1. Catechins also activate cool/cold receptors, so serving green tea at a cold temperature may bring out their bitterness. That's because the trigeminal system serves as a volume dial, so that when there is congruence between the actual and perceived temperature of a compound, the flavor of that compound is amplified.
Type II taste bud cells responsive to sweet use TRPM5, a warm receptor, in their response pathway. In fact you can simply apply mild heat to the tongue, and many if not most people will interpret the sensation as “sweet.” That is why the warmer tea is sweeter, even when no sweetener has been added to it. It is also milder because the bitterness and pungency are dialed down.
Remember how I mentioned that color and flavor can be related? In this same study they asked participants about the color of the green tea, which in fact was a yellow. More participants saw a brown color in the tea when it was hot than when it was cold, and virtually none saw a green color in the hotter brew. 
In the emotional realm, the warmer tea was associated with positive emotional feelings and the colder teas with more negative feelings.
One more important conclusion of the study to include here: “Since females could better detect sample temperature-induced changes in sensory attributes than males, sensory attributes might contribute to likings of coffee and green tea samples among female participants, but not [as strongly] among male participants.”

In the US, and especially in the South, there is a strong tradition of consuming sweetened iced tea. The sweetness added to the tea counteracts the bitterness and astringency of the cold tea. An open question is whether sweetness can also add to the emotional positivity of the person drinking it!

*()*()*()*()*()*()*
To preorder "Tea: a Nerd's Eye View" go to 
Be sure to check out the "Variation" for the pre-order price.
The book should be completed in the next couple of weeks!

* Ragita C. Pramudya & Han-Seok Seo. 2018. Influences of product temperature on Emotional Responses to, and Sensory Attributes of, Coffee and Green Tea Beverages." Frontiers in Psychology, Gale Academic Onefile, https://link.gale.com/apps/doc/A522502274/AONE?u=nysl_sc_cornl&sid=AONE&xid=9c9e7154. Accessed 7 Sept. 2019.

Thursday, September 12, 2019

The shape of your tea cup and the flavors of your tea

Another excerpt from my upcoming book "Tea: a Nerd's Eye View:"

Tea is served in glasses, bowls, and cups that come in a multitude of shapes and sizes, made from an amazing array of materials. 
The effects of these different containers has not, to my knowledge, been explored in a systematic and scientific way, where (for example) shape is matched to the qualities of a tea. 
However, there is a growing body of evidence that the shape of a glass influences the aroma  of wine as you drink it. A tulip shape seems to do best for all types of wine. *

The tulip shape allows more aroma volatiles to escape from the surface of the wine; then it concentrates them at the opening at the top of the glass. Thus for wine, one of the important parameters for aroma is the ratio of the opening of the glass (top arrow) to the maximum diameter of the glass (bottom arrow). I was interested to note that the sulfur dioxide diminishes as the ratio goes down, suggesting that this gas is less likely to escape the more tulip-like glass.
A similar result was found for coffee: aromas were more intense when the coffee was served in a cup with a tulip shape, and sweeter when sipped from a cup with a wide opening. Whether these results were the consequence of expectations is open to question—in an online survey of coffee cup shape, respondents maintained that mugs with a narrow opening would be more aromatic, while short mugs with a wide opening would be sweeter.**
Nevertheless, ceramicist Peter Ting has offered a set of three porcelain cups, designed to bring out dfferent aspects of a tea: a “fragrance” cup, a straight sided cup, and a cup with a slightly flared lip.*** 
Towards the end of an extensive podcast on teaware, Kevin Gascoyne shared a tasting experience with host Ken Cohen, sipping a Bai Ruo Xiang Rock Tea from Wuyi from each of Peter Ting’s cups.****
The following table gives the results:

Fragrance cup
Straight-sided cup
Flared lip cup
First sips,
hot tea
Most aromatic, full, complex
Lighter, less flavorful compared to fragrance cup
Less complexity than with fragrance cup, but more “minerality.”
Cooled down
Same
More fruity and “darker” than at first
More complex than first sip, notable minerality


Ting’s fragrance cup is tulip-shaped with a slight flare at the top—the same principle applies here as it does with the tulip-shaped wine glass: aroma volatiles accumulate in the headspace of the cup and then funnels them to your nose and mouth. This cup was designed especially to take advantage of the aromatics in oolongs—this Rock Tea benefitted from this cup.
The straight-sided cup didn’t do justice to the tea. Ting and colleagues found that a straight-sided cup was best for black teas. Black teas, and especially teas made from assamica leaves, tend to be brisk, which is another way of saying that they activate both TRPA1 and TRPV1 receptors on the trigeminal nerve. The straight-sided cup delivers the tea further back in the mouth, where there are more of these receptors, especially TRPV1, so you can expect greater briskness. 
The Wu Yi Rock Tea served by Kevin Gascoyne in this trial lacks many of the TRPV1 activating chemicals, so the “brisk” effect is absent, while the shape of the cup allows the aromatic compounds to escape before you sip, rendering the tea less flavorful. 
As the tea cools down in the cup, however, the warm cool/cold reeptors of the trigeminal nerve are less inhibited by the hot temperature of the tea. The fruity compounds that activate TRPV3, the warm receptor, and TRPM8, the cool receptor, are no longer suppressed, so these flavors can be appreciated—remember, trigeminal activation serves as a volume dial, and trigeminal receptors usually inhibit each other. The one exception: under certain conditions, TRPV! and TRPA1 can mutually enhance, giving the brisk sensation.
Finally, the cup with the slightly flared lip was designed for green tea. The slight flare delivers a wider flood of tea into the mouth, activating more taste buds in the front and sides of the tongue, and fewer in the back. There are proportionally more bitter receptors in the back of the tongue than in the front: this delivery gives the sweeter elements of a green tea a better chance to dampen the  bitterness.  

It’s interesting to note that the flared lip cup yielded a greater sensation of minerality from the Rock Tea. This sensation probably comes from activation of the trigeminal receptor TRPA1. When less fragrance from the tea reaches the nose as you sip, the trigeminal effects in the mouth and throat can become more prominent. As the tea cools down, the ability of TRPA1 to respond increases (it's the cold receptor), so sensations of minerality increase.

All in all, the shape of your cup matters!

Francesca Venturi, Gianpaolo Andrich, Chiara Sanmartin, Isabella Taglieri, Giancarlo Scalabrelli, Giuseppe Ferroni & Angela Zinnai (2016) Glass and wine: a good example of the deep relationship between drinkware and beverage, Journal of Wine Research, 27:2, 153-171, DOI: 10.1080/09571264.2016.1160879 
** George Van Doorn, Andy Woods, Carmel A. Levitan, Xiaoang Wan, Carlos Velasco, Cesar Bernal-Torres, Charles Spence,Does the shape of a cup influence coffee taste expectations? A cross-cultural, online study. Food Quality and Preference, Volume 56, Part A, 2017, Pages 201-211. https://doi.org/10.1016/j.foodqual.2016.10.013.
*** You can find more about these cups , including pictures, at https://peterting.com/branding. 

Wednesday, August 21, 2019

Classical Chinese poetry and the aftertastes of oolongs

Another excerpt from my upcoming book, "Tea: A Nerd's Eye View:"

You may see Tie Guan Yin tea advertised as having a “Yin Yun” or “Yin Rhyme” aftertaste, and Wuyi rock teas as having a quality called “Yan Yun.” “Yun” in this context means “rhyme.” 
What would a rhyme have to do with a tea’s aftertaste?
With respect to rock teas, “Yan” can mean “rock,” but it also refers to the “male” principle—saying that rock tea has “Yan” is really a pun.
To understand the many layers of this play on words, it is important to know that Chinese singing and by extension Chinese poetry have a Yan (masculine) and Yin (feminine) rhyme system.
This system differs from the rhyme systems in English, though we have some of the same underlying concepts of masculine and feminine. In English we speak of masculine rhymes as consisting of one syllable, and feminine rhymes as consisting of two or more syllables. The English masculine rhyme can be abrupt and in your face, while the feminine rhyme is more supple and musical. The Chinese masculine and feminine rhymes have similar qualities.
As Ray Wen Wei states:
“Shih is a modem style of poetry (''jin ti shi") matured during the early Tang [618-690 CE]. It constrains a poem to eight lines of five or seven syllables each. With a single rhyme [system] running through it, the poem is divided into four pairs, namely "start­ing," "extending," "turning," and "completing," respective­ly. These appear in the western classical sonata form of music in the same order, as the "theme," "development," "transi­tion," and "recapitulation." The rhyme used throughout the poem is chosen from one of two divisions of the vowel sounds. In general, these are divided as either long, bright sounds (called "yang" rhyme) or short, dim sounds (called "yin" rhyme). The choice of this rhyme determines the mood of the poem, similar to the choice of a major or a minor key in music.” *
The Yan Yun "masculine" aftertaste of, say, a Ruo Gui rock tea, classically lingers for a long time. It gives you the clear bright impression you would expect from activation of TRPA1, the trigeminal cold receptors in the throat.
By contrast, Tie Guan Yin gives a sweet, gentle, more muted after-taste—breathy rather than clear—the quality that Pulleybank and his colleague ascribe  to the Yin speech tones in Chinese.**
Here is a Chinese poem about tea, with translation and important-to-read notes at http://chadao.blogspot.com/2009/04/song-dynasty-tea-poem-zhu-xis-tea-stove.html
茶灶 朱熹 CháZào -- Zhū Xī (1130-1200 CE)
仙翁遺石灶 xiānwēng yíshízào宛在水中央 wǎnzài shuǐzhōngyāng飲罷方舟去 yǐnbà fāngzhōuqù茶煙裊細香 cháyān niǎoxìxiāng 
'Tea Stove' by Zhu Xi 
Stone stove left behind by immortals,Lies crooked in the center of the stream.
Tea finished, two boats drift on abreast,Tea smoke; wafting delicate fragrance.
The "grave accent" in pinyin indicates the short breathy falling tones of a "Yin" rhyme...
...and here is a photo of the Nine-Bend River in Wuyi, the location of the poem, by Zhangzhugang, Wikipedia,  CC BY-SA 3.0 license.


(Incidentally, notice the orange-red color of the Wuyi rocks. It comes from the presence of iron. Excess iron causes tea plants to produce kaempferol, a flavonoid that binds up the iron so it doesn't damage the plant. In your mouth  kaempferol activates TRPA1—the cause of the Yan Yun effect of Wuyi rock tea.)

* Ray Wen Wei . Chinese classical poetry is based on universal principles of singing.  EIR Volume 19, Number 13, March 27, 1992.

**E. G. Pulleybank and 蒲立本. “The nature of the middle Chinese tones and their development to early Mandarin/中古汉语声调的本质和到早期官话的演变. Journal of Chinese Linguistics, vol. 6, no. 2, 1978, pp. 173–203. JSTOR, www.jstor.org/stable/23752830.

Sunday, August 18, 2019

Tea, Cha, or Chai?

Here is an excerpt from my upcoming book "Tea: a Nerd's Eye View." Victor Mair, whose work is the source for this blogpost, is Professor of Chinese at the University of Pennsylvania. I had the privilege of meeting him first through my brother-in-law, who was his classmate as they were working on their PhDs in Chinese at Harvard, and subsequently at the extraordinary exhibit of the Tarim mummies at the University of Pennsylvania (Here's a Youtube video of his talk about the mummies). Since the publication of his book with Erling Ho, "The True History of Tea," he has been in demand as a speaker at tea events throughout the US, including one at my old academic home, Cornell University, entitled "Tea High and Low: Elixir, Exploitation and Ecology Conference" (October 26 - 27, 2018) where I had the pleasure of meeting him again.

According to sinologist and linguist Victor Mair, as outlined in Appendix C of his book with Erling Ho, “The True History of Tea,” the words used for tea in the world’s languages have followed the paths taken by the leaf itself.
The genetics of the Camellia sinensis plant show that it was first cultivated in areas neighboring the Yun-Gui plateau, while it was used as a wild plant both there and in the corner joining Southwest China, Tibet, India, Bhutan, and Myanmar/Burma.
The languages spoken in the Yun-Gui area belonged to the Austro-Asiatic group, the oldest language group South Asia. These languages appear to have spread south from there along the course of the Lancang/Mekong River, where we find both wild and cultivated Camellia sinensis today. 





Map of the Lancang/Mekong River basin. Grey shows the areas from which the Austr-Asiatic languages spread. The large red dot indicates the general area of the Yun-Gui plateau. The smaller red dot indicates Xishuang-banna on the banks of the Lankang/Mekong River, a center for  puer production—fermented teas were among the first teas exported. The green dot indicates the Southwest China/Tibet/India/Bhutan/Burma-Myanmar corner, where Tibeto-Burman languages are spoken. The dark red arrow points to the Nu/Salween River, and the green arrows to the Irawaddy River. 
Map by Shannon1, provided by Wikipedia under the GNU Free Docu-mentation License Version 1.2. Dots and arrow added.

In the Austro-Asiatic language group the word for a leaf was originally “*la.” (The asterisk indicates a reconstruction.) People speaking Mon-Khmer languages, a language group descended from Austro-Asiatic, settled among the botanic riches along the Irawaddy, Lancang/Mekong and Nu/Salween rivers. “La” became the specific term for Camellia sinsnsis when consumption of the leaf as a fermented salad or chew became an integral part of their culture, and variations on the theme of tea infusions were practiced, probably about 5000 years ago, or possibly earlier. 
Sinetic-language speakers (= people who spoke some form of what was eventually become one or another variant of Chinese) came into contact with the Mon-Khmer people and their tea culture some 3000 years ago, and began the deliberate cultivation of Camellia sinensis in what is now Sichuan. 
The “First Emperor” Qin Shi Huang (also called Shi Huangdi) conquered the people living and growing Camellia sinensis in Sichuan, and, by 221 BCE, brought the practice of drinking tea into Chinese culture. 
Eventually, cultivation spread, to neighboring Fujian in particular where the plant may have hybridized with local wild plants to give the many different leaf forms now seen in Fujian.
In the sinetic Southern Min language of Fujian and Taiwan, “*la” was transformed via “dra”—apparently an old sinetic form—into “te.”
Outside the Southern Min-speaking areas “*la” evolved into “cha,” 
Tea was brought to Korea and Japan via the northern route, so the word in those languages is “cha.” 
The Portuguese were the first to bring tea to Europe and called it “cha,” the pronunciation in Guangdong—they held Macao in that province until 1999. However this pronunciation did not gain traction in the rest of Europe, because the quantities of leaf imported were so small. 
It took the Dutch to bring large quantities of tea to Western Europe in the 17th century. They traded in Amoy (now called Xiamen), in Fujian, as well as in Formosa (now Taiwan) and brought the “te” pronunciation with them to Western Europe.  
“Chai” sounds like a transformation of “cha.” According to Victor Mair, it is indeed a transformation of “cha,” one first created in Persian to become “chay.” People on the land routes through Central and Western Asia to the Middle East and Eastern Europe used Persian as a common language of trade at the time when tea drinking spread to these areas.  
Thus “chai” was brought to India from Central Asia by the Moghuls in the 16th century, then picked up in Hindi-Urdu, and finally it came into English.