Oolong-hai and lychees

Came across this fascinating photo by Chinh Le Duc when searching for tea images on Unsplash.com. The title words read: "Drink, glass, cocktail, beverage and alcohol."  

Photo by China Le Duc, Unsplash.com

Alcohol? When my keyword search was "tea?" What is going on here? 

Come to find out that there is an iced alcoholic beverage called oolong-hai consisting of oolong tea combined with shōchū, a Japanese drink fermented and distilled from any one of a number of starches, including rice, barley, buckwheat, and interestingly, sweet potatoes. Apparently the choice of starch conveys a distinctive flavor to its shōchū. 

Here's what Sara Shacket of the blog Tea Happiness* has to say about the oolong-hai she savored:

"The drink was incredibly refreshing on a hot NYC summer evening. I tasted the slightly bitter earthiness of the Oolong, along with a subtle hint of something smoky that reminded me of whiskey. Shochu has a subtle flavor, and so my drink didn't have the overwhelming alcoholic taste that I usually expect from a cocktail. This makes the drink quite dangerous for me. I hardly even noticed that I was consuming any alcohol! It had a similar refreshing feel to the mugicha I recently tried.  I also love that it wasn't sweet. In fact, the server warned me that it wasn't a 'sweet cocktail'."

At another (commercial) website,** found a good photo of oolong-hai, along with a recipe:

Oolong-hai from https://umamimart.com/blogs/main/japanify-oolong-hai

Comparing this photo with the one by Chinh Le Duc, it looks very much the same: same color and cloudiness. 

Which led me to the next question, namely would lychees go well in this drink?

Looked up the chemistry of lychees in a paper by colleagues of mine from Cornell, Peter Ong and Terry Acree.*** Turns out that lychees share a number of flavor-significant compounds with oolongs. Some of these, such as linalool, are found in all teas, but the one that stood out for oolongs specifically is furaneol, aka strawberry ketone, which activates the warm receptor, TRPV3. Another important flavor compound in lychees, and perhaps in some oolongs, is vanillin, which also activates TRPV3.  But most striking is the presence in oolongs of cis-rose oxide, which has a characteristic lychee aroma.**** Put together, oolong and lychee will each expand the flavor of the other.

In case you are wondering, I haven't experienced the drink myself. I lack functional aldehyde dehydrogenase, so become quite sick with very little alcohol, and despite my love for oolongs, I really don't like lychees—and now I know why. Lychees have δ-decalactone, which has a strong flavor of coconut. Can't stand the flavor of coconut, and lychees come across as too coconutty to me. So I am not about to try this drink, no matter how hot it gets this summer. 

But you might enjoy it very much!

* http://www.tea-happiness.com/2011/08/oolong-shochu-yes-please.html
** https://umamimart.com/blogs/main/japanify-oolong-hai
*** Ong, P.K.C., and Acree, T.E.. Similarities in the Aroma Chemistry of Gewürztraminer Variety Wines and Lychee (Litchi chinesis Sonn.) Fruit. J. Agric. Food Chem., 1999, 47 (2), pp 665–670
DOI: 10.1021/jf980452j.
**** Sheibani, E., Duncan, S. E., Kuhn, D. D., Dietrich, A. M. and O'Keefe, S. F. (2016), SDE and SPME Analysis of Flavor Compounds in Jin Xuan Oolong Tea. Journal of Food Science, 81: C348–C358. doi:10.1111/1750-3841.13203

Fresh versus dried fruits

The other day a friend of Pairteas asked me why certain fruits—blueberries, kiwis, and apricots in particular—go better with oolongs when dried than when fresh.

The first point to make is that the chemicals in oolongs for the most part activate the warm to hot receptors. Consequently foods that activate the cool/cold receptors, such as blueberries and apricots, will cause the flavors of most oolongs to disappear.

The second point is that drying, whether of fruit or tea leaves, changes their chemistry. When they are fresh, fruits and tea leaves are still alive, so they respond to drying by making defense chemicals in response to the stress. 

For example, fresh ginger has two chemicals, zingerone and gingerol, that are slightly different in flavor. Zingerone activates the cold receptor (TRPA1) and gingerol activates the hot receptor (TRPV1). As ginger dries, these chemicals disappear or, to be more exact, are transformed into shogaols that collectively activate TRPA1. For those of you who were at our WTE about green tea way back in 2015, you might remember how a tiny bit of dried ginger dampened the bitterness of the tea and brought out its herbaceous qualities.

Apricots have compounds that hit the cold receptors, so can kill the flavor of an oolong.  As apricots dry phenyl ethyl alcohols and linalool oxides oxides appear—they hit the warm/hot receptors and make oolong happy.

As for blueberries, don't know what happens in them specifically. Fresh blueberries hit the cool/cold receptors, as does blueberry jam—the berries don't have a chance to make an abundance of stress chemicals before they are cooked and their enzymes denatured. My guess is that drying makes them create a panoply of chemicals similar to those in apricots.

And as for kiwis—will have to do some experiments once I get settled in my new home...

...and please do experiments yourselves to see what happens. Would love to hear from you!

Asparagus, coffee, and tea

Had a fascinating experience the other morning. Bought a lightly roasted coffee called Stargazer from our local specialty coffee roaster, Gimme!. Flavor description from the package: "dark chocolate, bourbon cherry, caramel, stone fruit sparkle."

Stargazer coffee beans—notice the light color and lack of oil, indicative of a light roast.

I got the chocolate and maybe the caramel, certainly the sweet, but was overwhelmed by the coffee's vegetal taste — clearly asparagus. It even had that sweetish asparagus after-taste, all of which led me on a hunt for understanding how these flavors came to be in the coffee...and in green and oolong tea, too.

As I said in my book, "Three Basic Teas & How to Enjoy Them:"*

"The strongest odorants, and perhaps the most numerous, in asparagus are sulfur-containing and nitrogen-containing compounds—these can be detected by the human nose at the level of parts per billion. They will dominate any aroma mixture you can imagine. 

Of these 20 or so typical compounds in asparagus, the most abundant is dimethyl sulfide. This compound can be present in green and oolong tea, where it contributes a “marine/seashore/oceanic” quality. But if you associate that smell with cooked asparagus, then you would say it’s an asparagus smell. You could also associate that smell with the odor of urine after eating asparagus—the people who have the gene for breaking down asparagusic acid excrete dimethyl sulfide among other compounds."

Dimethyl sulfide doesn't give the asparagus aftertaste, however. Another sulfur compound that could be a candidate: methionyl acetate. It's in both coffee and asparagus, and beer, too. But it doesn't give a sweet aftertaste as far as I can tell.**

Perhaps the sweet aspect comes from an entirely different set of compounds, the pyridines, which abound in coffee, especially with light roasting. Pyridines can be sweet, even too sweet, though many also have a grassy quality. Turns out that 2-ethyl pyridine gives a sweet yet green grassy quality to asparagus—in fact, some people consider it to be "the" asparagus scent. (Worth noting that it is in black tea as well.)

The conclusion I reached from this hunt (and so many others) is that foods from plant materials such as tea, coffee, and asparagus, share a host of basic chemicals—the resulting flavors may well simply depend on which chemical stands out in the mix. 

* You can get a copy of "Three Basic Teas & How to Enjoy Them" either from the printers:  https://www.createspace.com/6961595, and get a 10% discount using the code V97A7SQ3; or from Amazon—sorry, couldn't get a discount with them.

** Ulrich, D., et al. Contribution of volatile compounds to the flavor of cooked asparagus. Eur Food Res Technol (2001) 213: 200. doi:10.1007/s002170100349.

More World Tea Expo 2017!

One of the many observations from my workshop "Pairing with Tea: the Science of Flavors and How to Enjoy Them:"

We enjoyed an exquisite English Breakfast Tea from The Tea Source.

Here's a picture of English Breakfast Tea from The Tea Source.

But drink the English Breakfast tea after a bite of a Walkers shortbread, and the tea disappears!

Here's the delicious shortbread that we used  — great by itself, but with black tea you need to add something!

Add some raspberry jam to the shortbread and bite again and sip the tea, and the tea magically comes back!

What is happening?  

The black teas in the blend activate TRPV3 and TRPV1, the warm and hot receptors, to give you a full comforting black tea flavor — remember, these receptors and the trigeminal nerves to which these receptors are attached act like a volume dial, upping the flavor experience.

The butter in the shortbread?  Turns off TRPV1, so you can't taste the tea.

But when you add some raspberry jam, raspberry ketone — a major chemical in raspberries, and in black tea, too — turns TRPV1 back on, and TRPV3 as well, so now you get the warm delicious tea flavor back again!

Strawberry and blueberry jams don't do this...

What does this mean for all of you who serve tea? 

Whenever someone asks for a black tea with a buttery pastry, make sure that the pastry contains some raspberry!

Day 1 of World Tea Expo 2017 — Talk, more talk, and a Dragon Dance!

Day 1 of World Tea Expo 2017 has been such a blast! Started the morning with my session on cold brew versus hot brew—what's in the cup and why you like it. There were two bottom lines to my talk: 1) in general people will tend to prefer teas that have a higher ratio of sweet amino acids to bitter catechins and polyphenols, and cold brewing when done right will yield a tea with the most tasty proportions, and 2) you should experiment with the teas you like, and see what happens with cold brewing—vary the ratio of leaves to water, the brewing time, and the temperatures, and see what your taste buds tell you...and, I should add, see what your friends and customers tell you.

As I mentioned at my talk, if you email me (virginia@pairteas.com) I will be happy send you a copy of my presentation -- just let me know whether you would like a Keystone or a Powerpoint version.

After the talk my ever so diligent helpers for tomorrow's session on pairing with tea discussed with me the plan for the tastings—will tell you all about that tomorrow.

Meanwhile here's a picture from the Dragon Dance that open ed the Exhibit Hall — such a charming and skilled performance by the young people of Kung Fu of Las Vegas—see http://www.lvshaolin.com/lion_dance/.

Iced Tea Deconstructed - Part 2 - Ceylon Black Tea with Rose Water & Cardamom

This series of blog posts is based on the eBook published by Lu Ann Pannunzio and her colleagues (Nazanin from Tea Thoughts & Bonnie from Thirsty for Tea) that can be ours if you if you sign up for Lu Ann's blog newsletter— go to http://theteacupoflife.com and sign up!

The next iced tea in the list, based on rose water, cardamom, and black Ceylon tea, in the Persian way that Nazanin Yousefnejad of Tea Thoughts treasures.

Why does this particular combination make for an exquisite iced tea?

First, black teas in general, and Ceylon black tea in particular, contain a host of chemicals that they share with roses, so the rose water brings out the flavors of the tea. You need make a special effort to bring these flavors out in an iced tea because many of them activate the warm/hot receptors, which is turned off by cold. I am thinking particularly of beta-damascenone, which gives the rich warm smell to damask roses. Of course there are cool smells in both roses and black tea as well — am thinking of linalool, geraniol and nerol, all of which activate TRPM8, the cool receptor. However these are not as abundant in black tea as they are in green tea. Instead, the processing of black tea yields linalool oxides, which are warm/hot, so any help the warm/hot receptors can get with rose water to boost the black tea flavor is huge for your enjoyment.

Which brings me to cardamom. My guess is that green cardamom is the ingredient intended. If you look at the composition of cardamom essential oil from green cardamom, it offers a curious mix of chemicals, some of which activate the cool/cold receptors (e.g. limonene), and some that actually turn off TRPA1, the cold receptor that leads to pain (e.g. borneol).* The latter chemicals can actually give your iced tea a "warmer" feel, and decrease the pain that the ice could cause.

When you taste plain cardamom, you will notice that its flavor seems to change, shifting from cool to warm as these different receptors kick in — remember that cool receptors are quick-on-quick-off, while warm and hot ones are slow-on-slow-off. It's this sequence that makes the flavor of cardamom so fascinating and hard to characterize! 

So go get your copy of the eBook and enjoy these marvelous flavor nuances for yourself!

** Masayuki Takaishi, Kunitoshi Uchida, Fumitaka Fujita, Makoto Tominaga. Inhibitory effects of monoterpenes on human TRPA1 and the structural basis of their activity. J Physiol Sci (2014) 64:47–57 DOI 10.1007/s12576-013-0289-0.

Iced Tea Deconstructed - Part 1 - Matcha Mojito Mocktail

Lu Ann Pannunzio (with her colleagues (Nazanin from Tea Thoughts & Bonnie Eng from Thirsty for Tea) has something special for you if you sign up for her blog's newsletter: an iced tea recipe book — 6 Refreshing and Fun Iced Teas — with one recipe for each of five teas and a tisane! 

Go to http://theteacupoflife.com and sign up! 

Meanwhile here is the first of a series of why these wonderful iced tea combinations work: 

The Triple M! Matcha Mojito Mocktail, from 6 Refreshing and Fun Iced Teas.

The first iced tea in the booklet is a matcha mojito cocktail, developed by Lu Ann. It contains matcha, mint leaves, lime juice and...maple syrup? How could those flavors possibly go with maple syrup?

You do need sweetness to cut the bitterness of the matcha, but maple syrup? After all, the first three ingredients, and particularly the mint, all hit the cool/cold receptors—so refreshing! But maple syrup is brown, and should hit the warm/hot receptors, right?

I couldn't find any data concerning the receptors for sotolon and maple furanone, the main flavor chemicals in pure maple syrup, so I did the experiment.

I paired maple syrup with a sencha and an English breakfast tea (experimentation is limited in my current temporary housing situation).

To my surprise, the maple syrup killed the flavor of the breakfast tea, while the sencha lost its bitterness and gained a wonderfully green and flowery flavor.

So there you are: all signs point cool/cold receptors for the chemicals in pure maple syrup.

Any other supporting evidence? Perhaps two things:

First, pure maple syrup gives you that catch in the throat that good quality olive oil gives you. With olive oil that catch is caused by oleocanthol activating TRPA1, the cold receptor.

Second, sotolon is characteristic of fenugreek. And what can you use if you don't have any fenugreek hanging around?* Maple syrup (no surprise there)...and mustard seed. That may be the clue: mustard, or, to be more exact, the isothiocyanates in mustard activate TRPA1!

So the next time you enjoy pancakes with maple syrup, match them with a green tea...and don't forget that activation of TRPA1 can make you feel wide awake!

And don't forget to sign up for Lu Ann's newsletter — it isn't just another thing to clog your email box. It's filled with freshness and light on all things tea:  http://theteacupoflife.com.

* https://www.spiceography.com/fenugreek-substitute/