Thanksgiving Part 2 — Succotash

A while back, before I retired from the Division of Nutritional Sciences at Cornell University, I helped write answer for a nutrition Q&A website that we called Nutriquest. Was looking over my files and found a four-part series I wrote for Thanksgiving. Here is the second part, lightly edited.  The next parts will be posted over the coming days.

In the US, the fourth Thursday of November is devoted to a very special holiday, Thanksgiving. The day is notable in that it is our national occasion to give thanks for the food that we have—and to help those who do not have enough food, here in the US and throughout the world.

Because food is such a central part of Thanksgiving, and because the Thanksgiving foods have such an interesting history, weaving together nutrition, agriculture and culture, we thought that we would take the opportunity this week to provide you with a series about the Thanksgiving foods, with a couple of recipes and cooking hints thrown in.

Succotash, a combination of corn and beans, is an extraordinarily nutritious dish that the Native Americans presented to the Pilgrims on that first feast of Thanksgiving.

What is succotash?

Succotash is the name given to a number of different dishes combining beans and corn (also known as maize in other English speaking countries). Present day recipes for succotash—and the frozen version I remember from my childhood—combine corn with lima beans. However, the dish the Native Americans introduced to the Pilgrims was certainly not prepared with lima beans—these beans were not available in the Northeast at that time—but was originally prepared with other large beans. You can find recipes on the web featuring black-eyed peas or black beans instead of lima beans—in fact from a nutritional point of view (as we will discuss below) most any fleshy bean will do.

Succotash made with red kidney beans. Image from Wikipedia.

Where does succotash come from?

The name for this mixture of corn and beans comes from the Wampanoag word msíckquatash meaning a boiled stew with corn. The Wampanoags are the Native American people the pilgrims encountered on Cape Cod.

The Native American versions of succotash were made with meat or fish in addition to the beans and corn. However, many of the important nutritional properties of succotash, discussed below, remain if you cook the dish without meat.

The beans that I grew up thinking of as part of succotash—lima beans—were certainly not the original beans used by the Native Americans in the Northeast. Lima beans are a more tropical bean, from Mexico (the small limas) and South America (the larger limas). They do not grow in the climate of New England. They need warm weather, a good amount of warm moisture (no cold water welling up from the ground), and a fairly long growing season—in other words, not the growing conditions prevalent in New England during the Little Ice Age when the pilgrims arrived in America.

We should note that the Native Americans of the Southwest developed strains of lima bean that were drought resistant to suit their climate. One of these is known as Hopi Orange, and is cultivated by the Hopis in the Southwest—see: https://coloradoplateauhorticulture.wordpress.com/2014/02/12/phaseolus-lunatus-how-the-hopi-brought-us-the-ancient-mesoamerican-lima-bean/

Why combine beans and corn in a meal?

Beans and corn in a meal together can give you better quality protein than can either of these foods alone.

What do you mean by better quality?

The proteins we eat are broken down into amino acids, which the body then uses to build its own protein. Our bodies are not able to manufacture most amino acids from scratch—as a result we must eat them pre-formed.

In order for our bodies to build new protein we need to eat the amino acids in the right proportion for making new proteins—as it turns out, this is the proportion found in foods of animal origin, such as meat or eggs, but not the proportion found in individual plant foods.

Then how do you get better quality proteins from plant foods?

By combining certain types of plant foods—and in particular, a grain and a legume, in other words, the corn and beans in succotash.

Grains and legumes are both fairly good sources of protein, because the part we eat is the part that is going to become the new plant. The new plant needs to rely on stores of protein in the seed until it has grown roots and can obtain its own nitrogen for creating amino acids.

Different plant foods have different proportions of amino acids—corn, rice and wheat lack the amino acid lysine, and may have low amounts of two other amino acids, threonine and tryptophan, but they have abundant quantities of methionine. Beans and peanuts have good amounts of lysine, threonine and tryptophan, but are short on methionine. By eating corn and beans together (or rice and beans, or tofu and rice...or a peanut butter sandwich!), you can have each plant food provide what the other is lacking. As a result, with these combinations you can obtain the proper proportion of amino acids, even if you don't eat much if any animal proteins. The process of combining two or more foods in order to get the right proportions of amino acids is called complementation.

Are there other important properties of succotash?

Corn and beans contain some important nutrients in addition to amino acids. These include generous amounts of folate and beta-carotenes. They also contain iron. But remember, the minerals in plant food are less well absorbed than the minerals in animal food, and decrease absorption of iron from animal foods, so don't count on the iron in corn and beans to help you get enough.

As you probably know, carbohydrates (and beans have plenty of them) cause blood sugar levels to go up after a meal. This is a normal process, but diabetics may have high blood sugar levels even before they eat anything, and may not be able to manage rises in blood sugar effectively after they eat. Beans are special in this respect: ounce for ounce of carbohydrate, beans do not raise blood sugar levels as much as other carbohydrate containing foods do. Further, it seems that if you eat beans with other carbohydrate-containing foods (for example corn), you won't get the rise in blood sugar levels you would see with the other foods alone. So beans may play a role in controlling blood sugar, and are an excellent food choice for diabetics. A note of caution, though, for our readers with diabetes—don't let eating beans take the place of monitoring your blood sugar levels, and don't count on beans alone to do what a well regulated well-balanced diet will do for your overall diabetic control.

So succotash is good for me—now how do I make succotash?

There are dozens of websites with recipes for succotash, which you can find using your favorite search engine. Ones we particularly enjoyed reading about are:

• Plimouth succotash from the Plimoth Plantation, a living museum of 17th century Plymouth, Massachusetts—the recipe feeds 150 people!
• and the succotash recipes provided by NativeTech.org—Native American Technology and Art—a treasure trove of recipes handed down by Native Americans.

As I peruse all these recipes, certain common features stand out:

• The proportions of corn to beans are equal—for example, two cups of corn to two cups of beans. This proportion is important for maintaining both flavor balance, and for the complementation of amino acids to work correctly.
• Many of the recipes call for (skim) milk ; in some recipes milk is added to the extent that the succotash may be transformed into a chowder—also a good choice.
• Virtually all the recipes have either leek or onion in them—the addition of one or the other will add exciting flavor to the dish, courtesy of activating TRPA1.
• A number of recipes include diced red peppers—as you can imagine this adds a note of color which looks very festive next to the brown and yellow of the beans and corn.
• We were interested to note that some recipes included walnuts, chestnuts, or another nut (a tasty choice would be hazelnuts)—if you like nuts, they will add to the healthfulness of the dish.
• Many recipes go heavy on the salt—remember that you can always add lemon juice to the dish instead of salt; in fact this particular dish is really "picked up" by the judicious addition of lemon juice; we suggest that each person should be allowed to put in the amount of lemon they wish because people differ tremendously in how much lemon flavor is "just right" for them.
• And a basic note—as we mentioned above, succotash is really a Summer dish, rather than a Fall dish, because in much of the country the fresh sweet corn season and the fresh lima bean season have passed by now. However, to enjoy the best taste possible, see if you can at least find fresh corn, and use dried beans rather than frozen ones. But even if you are stuck to using frozen vegetables, remember that you can add other fresh flavorful ingredients to your heart's content—and most of all,

Enjoy!

...More tomorrow!

Thanksgiving Part 1 — Cranberries

A while back, before I retired from the Division of Nutritional Sciences at Cornell University, I helped write answer for a nutrition Q&A website that we called Nutriquest. Was looking over my files and found a four-part series I wrote for Thanksgiving. Here is the first part, lightly edited.  The next parts will be posted over the coming days.

In the US, the fourth Thursday of November is devoted to a very special holiday, Thanksgiving. The day is notable in that it is our national occasion to give thanks for the food that we have—and to help those who do not have enough food, here in the US and throughout the world.

Because food is such a central part of Thanksgiving, and because the Thanksgiving foods have such an interesting history, weaving together nutrition, agriculture and culture, we thought that we would take the opportunity this week to provide you with a series about the Thanksgiving foods, with a couple of recipes and cooking hints thrown in.


A NUTRIQUEST THANKSGIVING - PART 1

A cartful of Thanksgiving foods—turkey, cranberries, sweet potatoes, yams, corn and lima beans for succotash, apples and pumpkin for pie, as well as lettuce for salad, and carrots and potatoes and onions to put around the turkey—no wonder these boys are rushing home!
We will start our series with cranberries, and present to you a couple of recipes for cranberry sauce— a link to Mama Stamberg's at National Public Radio, and one of our own, for people who prefer their sauce to be low-fat and a deeper red...

Where do cranberries come from?

Cranberries are native to the New England coast, and are one of three berries that are native to North America (the other two are blueberries and Concord grapes). Cranberries grow on vines that, if well cared for, live indefinitely.

Cranberry vines are very particular about their growing conditions, so the areas in North America where they are grown are limited to New England, New Jersey, the Northwest (Oregon, Washington State, British Columbia), Wisconsin and Quebec. The Northeast, Northwest, Wisconsin and Quebec all share the characteristic that the land was covered in glaciers in the last Ice Age, about 10,000 years ago. The retreat of the glaciers provided the ideal land for the formation of cranberry bogs -- layers of gravel, sand and clay, with abundant peat. The gravel, sand and clay provide just the right amount of drainage for these plants that prefer abundant fresh water, and the peat provides the acidic soil that keeps them healthy.

Here's a map of part of Plymouth County Massachusetts that I gleaned from the USDA Natural Resources Conservation Service. Cranberry bogs are indicated by the red outlines. As you can see the areas are near gravel pits and swamps.

What are cranberries good for?

Vitamin C

Long before vitamin C was discovered, and long before the English Pilgrims came to America, Native Americans knew that cranberries could prevent scurvy. In addition to eating cranberries fresh, they combined crushed cranberries, meat and fat into strips which they dried to form pemmican. Pemmican served as a food for winters and for long voyages, when fruits were unavailable.

Scurvy—the disease caused by vitamin C deficiency—was potentially a serious problem through the long cold winters in the Northeast. These winters were particularly long and cold during the "Little Ice Age" that lasted from the 13th to the early 19th centuries. Cold weather and large amounts of snow meant that fresh fruits, the primary source of vitamin C, were not available. Native Americans developed a number of different remedies for preventing scurvy, including the use of tree material, such as sassafras and American spruce, as well as cranberries. [Side note: spruce tip jelly is particularly delicious! and see footnote below about the native American use of spruce*]

Descriptions of scurvy by English and French voyagers, coupled with the descriptions of the native American remedies, led James Lind (1716-1794) to develop the experiments that showed that scurvy was not due to an infection, as had been thought in Europe, but due to a dietary deficiency. only aft er after Lind's death did the British Navy finally followed Lind's recommendation to add lemon juice to the sailors' rations.**

While scurvy may not be common in the US today, thanks to the year-round availability of fresh fruit, cranberries are a particularly good source of vitamin C.

Cranberry juice and urinary tract infections

Daily consumption of cranberry juice appears to be effective in diminishing the chances of developing, or suffering a recurrence of, urinary tract infections. It has long been thought that cranberry juice prevents urinary tract infection by acidifying the urine.

In fact, cranberry juice does not acidify urine in a consistent way—vitamin C by itself is better at that. Rather, cranberry juice works through another mechanism. The first step in the development of an infection requires that that bacteria stick to each other and to tissue surfaces, so that they don't get flushed out with the urine. Cranberry juice prevents this sticking, and thereby prevents the bacteria from getting a foothold in the urinary tract --and thus prevents urinary tract infections

Cranberry juice and cancer

There is intensive research underway to determine whether cranberry juice plays a role in preventing and treating cancer. There are theoretical reasons why it should do so, and some animal data that support this possibility.***

Cranberry juice, vitamin B12, proton pump inhibitors, and older people

Vitamin B12 requires an acid environment to be released from food. People who are using a proton pump inhibitor (two commercial names: Prilosec and Nexium) for heartburn or an acid stomach, or for stomach ulcers, or who are elderly, have very little acid in their stomachs and not enough to enable vitamin B12 to be released. Cranberry juice, because of its acid content, can take the place of stomach acid, and improve vitamin B12 release and absorption. So if you are over 65 or are on omeprazole, it might be a good idea to drink a glass of cranberry juice every day, along with your animal protein or yeast, the source of vitamin B12 in the diet.

So cranberry juice and cranberries are good for me—now how do I make cranberry sauce?

First, my recipe, developed for people who like their cranberry sauce sweet and spicy:

• Wash and then plunge about four cups of cranberries into clear boiling water, just long enough so that they burst, and the skins will come off easily;
• Strain the berries through a strainer (preferably stainless steel so the flavor of the metal doesn't leach into the sauce), and capture the thickened juice;
• Meanwhile, take a medium red onion (or half a large one) and cook it in vegetable oil until the onion is translucent (you can omit this cooking step if you like your onions to taste strong—cooking breaks down allicin, the pungent compound that activates TRPA1, the cold receptor—red onions are sweeter and milder than others, and I happen to like the flavor without the pungency);
• Put the berry puree and drained onions in a food processor, and add the following:

1. a heaping tablespoon or two (or three) of dark brown sugar (how much depends on how sweeeeeet you want your sauce to be);
2. a pinch of fresh ground pepper;
3. a 1/4 teaspoon of cinnamon powder, to taste;
4. a pinch of clove powder;
5. you may also also want to add a peeled segmented orange, but remember to remove all the white strings, which are bitter;
6. and then the secret ingredients—a teaspoon of powdered dark chocolate or chocolate liqueur, and a tablespoon of coffee liqueur or cream sherry, or preferably both to total of about one tablespoon (for those of you who don't drink alcohol, you can substitute two teaspoons of very strong coffee); and a teaspoon of dark balsamic vinegar.
7. At this point I run the food processor to be sure all the ingredients are mixed.

• Finally, the juice of half or so of a lemon—this takes the place of salt.

I should confess here that I don't really measure when I cook—so when I put together this cranberry sauce I taste it after I add each of the spices and the secret ingredients to see if I have the balance right, and I usually end up adding a little more of one or the other. I add the lemon at the end little by little because it brightens the flavors (it activates TRPA1, the cold receptor)—with tastes in between to be sure not to overdo it. If I overshoot, I just add back one of the ingredients that activates the warm/hot receptors, such as brown sugar or a pinch of cinnamon.

• Run the food processor again until the ingredients are thoroughly mixed, then put in a glass bowl, and chill immediately. May be kept for one to three days in the refrigerator.
• Enjoy!

And here's Susan Stamberg's Mama's version of Craig Claiborne's cranberry relish from National Public Radio.

*Note that Jacques Cartier and his companions, in their first winter in what is now Canada (1536), suffered from scurvy, and survived thanks to the remedy prepared for them by local first American women from a tree that was probably a spruce. Samuel de Champlain's men were not so lucky: see Thomas A.Crist, Marcella H.Sorg. Adult scurvy in New France: Samuel de Champlain's “Mal de la terre” at Saint Croix Island, 1604–1605. International Journal of Paleopathology. Volume 5, June 2014, Pages 95-105.
** Peter M. Dunn. James Lind (1716-94) of Edinburgh and the treatment of scurvy.  Archives of Disease in Childhood - Fetal and Neonatal Edition. 1997;76:F64-F65. http://fn.bmj.com/content/76/1/F64

*** Jennifer Clarke, and Laura A. Kresty. Cranberries and Cancer: An Update of Preclinical Studies Evaluating the Cancer Inhibitory Potential of Cranberry and Cranberry Derived Constituents. Antioxidants 2016, 5(3), 27; doi:10.3390/antiox5030027.

Why does eating something sweet and then something sour produce an even more sour experience?

One of the most interesting phenomena you may have observed when eating a sweet dessert then taking a sip of wine, especially a dry wine with a high alcohol content, is that the wine tastes even drier and more sour and tannic than when sipped by itself. Why is this the case?

To understand what is happening we need to go back to a variant of the diagram in my book, "Three Basic Teas & How to Enjoy Them," and add an interesting property of "sweet" that you may have experienced with coffee and some teas.

First the diagram, of the taste cells in a taste bud:

As you can see, there are five different cells in this diagram. The first one, one the left is a Type I cell, and is sensitive to salt, especially to salt at low concentrations. The next three cells are Type II cells. Each Type II cell is sensitive to one taste modality, so in this diagram we have one cell each for bitter, sweet, and umami. Finally, on the right you find a Type III cell, which, as shown here, is sensitive to sour.

In addition to being sensitive to sour, Type III cells are also sensitive to heat, salt, and the burn of alcohol, because they have TRPV1 receptors on their surface.

With respect to salt and bitter (I haven't included an arrow for this interaction, for simplicity's sake): while we do not know exactly how Type I cells communicate their messages, their activation  turns off the Type II cells responsible for bitter sensations. That's why a tiny bit of salt will make tea, wine, and tequila less bitter.

Next to the connections shown in the diagram:

As indicated by the lines, Type II cells can communicate directly to the nervous system and brain. However the primary route of communication is through activation of Type III cells. Bitter, sweet, and umami messages can go through to the brain by either route so long as Type III cells are not activated by something sour or by something that activates TRPV1, such as high salt or alcohol.

However, if you eat something sour or something that activates TRPV1, Type III cells will inhibit messages coming through from the Type II cells, so perception of bitter, sweet, and umami is diminished.

Now to the interesting properties of "sweet:"

You may have had the experience of swallowing a mouthful of tea with lemon and then getting a lingering sweet aftertaste. When a sour compound is washed out and Type III cells are no longer inhibiting the Type II sweet cells, the brain interprets this condition as "sweet." The same thing can happen with coffee and artichokes: they contain compounds that inhibit Type II sweet cells, so that when washed out, you get a sweet aftertaste.

The opposite appears to happen when you wash a sweet compound away with something sour. When sweet goes away, something that is sour will seem more sour because nowType III cells are inhibiting Type II cells. Any sweet message is diminished and the brain interprets this condition as "very sour." This effect can be amplified by alcohol, especially by wine with its low pH and high titratable acid, because TRPV1 on Type III cells will be activated as well. 

In other words, sweet and sour exist in a balance, where the more sour something is the less sweet it will seem, and vice versa.

As a side note, I happen to be homozygous for a mutation in TRPV1 that increases this receptor's activation potential.* As a result, for me any wine with an alcohol by volume (ABV) greater than about 12% burns like crazy. Yet I can tolerate Harvey's Bristol Cream Sherry at 17.6% ABV. Why? Because that sherry is very sweet. The sweetness message is so great that the burn message can't get through. 

Apparently I am not the only person who has this experience: Tim Hanni MW and I have data that shows that people who avoid "big reds," dry wines with a high alcohol content such as California Cabernet Sauvignons, are happy with sweet cocktails that often have an even higher alcohol content than Harvey's Bristol Cream.**

Tim summarizes this pairing experience in the following diagram:

You can find this diagram and a whole lot more in his book "Why You Like the Wines You Like: Changing the Way the World Thinks about Wine." Go to http://www.timhanni.com/publications/.

Oh, and about teas for dessert: if you eat a sweet dessert, black teas will seem more astringent, because highly complexed polyphenols and a host of other compounds in the tea also activate TRPV1—activation of TRPV1 is required for astringency.***

Here's a very good summary reference for the way taste bud cells work: 
Bernd Nilius and Giovanni Appendino. Spices: The Savory and Beneficial Science of Pungency. Rev Physiol Biochem Pharmacol, doi: 10.1007/112_2013_11, Springer International Publishing, Switzerland, 2013. If you can't get the full reference on line, you can get relevant parts of it through googlebooks.

* Alissa L. Allen, John E. McGeary, and John E. Hayes. Polymorphisms in TRPV1 and TAS2Rs associate with sensations from sampled ethanol. Alcohol Clin Exp Res. 2014 October ; 38(10): 2550–2560. doi:10.1111/acer.12527.

** Tim and I have a summary of our report on the topic that you can find at https://www.jancisrobinson.com/files/pdfs/HanniUtermohlenSweetTolerant3.pdf. Thanks Jancis!

*** Nicole Schöbel et al. Astringency Is a Trigeminal Sensation That Involves the Activation of G Protein–Coupled Signaling by Phenolic Compounds. Chem. Senses 39: 471–487, 2014 doi:10.1093/chemse/bju014.

 

 

 

Sara, Georgia, and Jee present green teas and mochi cakes

Another adventure in tea pairing by our intrepid trio, Sara, Georgia, and Jee!

These three tea bloggers have been enjoying tea-food pairings in exquisite venues all around New York City. Here are the links to the tea pairing I'll discuss this time, with its focus on pairing green teas with mochi cakes:

Georgia: http://www.notesontea.com/2017/08/tea-pairing-101-green-tea.html
Sara: http://www.tea-happiness.com/2017/08/tea-pairing-101-green-tea-and-mochi.html
Jee: https://www.ohhowcivilized.com/tea-pairing-101-green-tea/

The green teas were a Japanese Sencha, a Chinese Long Jing, and a Korean Woojeon. 

Left to right, Sencha, Long Jing, and Woojeon. Note the colors from pale green to green-brown with increasing roast.
Image from Jee's blog. 

The kill-green process (that is, the process for denaturing the oxidase enzymes with heat and thus stopping oxidation) for sencha is steaming. The resulting tea has almost exclusively "green" compounds, and a strong vegetal flavor that Georgia and Sara said tasted like asparagus, while Jee said it was like spinach. As a result the chemicals in sencha activate the cool/cold receptors almost exclusively.

By contrast, the Long Jing is quickly pan-fired and the Woojeon is pan-fired for a slightly longer time. The result is the development of compounds that we taste as roasty and nutty, all against a background of green vegetal-ness. Compounds in these teas activate the cool/cold receptors as well, but also activate the "hot" receptor TRPV1, which is why we get a roasty/nutty quality from them. Depending on the balance of these chemicals in the cup and mouth and on the pairings, one or the other flavor type will dominate.

The mochi cakes. Image from Georgia's blog.

The mochi cake selection included a strawberry with rose that had a fresh strawberry in its center. This cake may have been delicious on its own but was no good with any of the teas. This result is not surprising: the main flavor compound in strawberries, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (Furaneol®), activates the warm receptor TRPV3. Activation of this receptor clashes with activation of the cool/cold receptors, so they cancel each other out and the result is, as Sara put it, "intense sweetness" that overwhelmed any other flavor.

The next mochi cake selection was "Black warabi (bracken) mochi: adzuki bean paste / black warabi (bracken) skin / cinnamon kinako (roasted soybean powder)." It was a runner-up with the Woojeon, according to Jee. The results of this pairing, too, makes sense. The bracken has a somewhat vegetal taste, and cinnamon has compounds that activate both the cold (TRPA1) and the hot (TRPV1) receptors, so it should go well with a tea that has these qualities.

The third mochi cake selection was the winner with all the teas, fresh fig and pistachio mochi: fresh fig / pistachio paste / mochi skin [infused] with black mission fig balsamico. 

Judging from the purple skin color in the photo, as well as the description, the fig chosen for this mochi cake was a Mission fig, considered the most flavorful of the California fig varieties. While the chemical composition of fig fruits has not been exhaustively studied, there are certain compounds that appear to be common to all fig fruits. Among these are (E)-2-hexenal, the compound that grass makes and releases when it is cut. Tea leaves make this compound when they are plucked—it's one of the compounds that give green tea its "green-ness." 

Two other compounds that jumped to my attention in reading the list of fig volatiles were menthol and limonene, which as you can guess from their names are in mint and lemon. They are sensed as cool and refreshing because they activate the cool (TRPM8) and cold (TRPA1) receptors. 

And then the fig was described as "sweet." Well, figs and tea both have methyl salicylate. This is the compound that gives wintergreen its odor, and tastes very sweet. While there is more of this compound in black tea (it is produced during oxidation of the leaves) there is a little in green tea, especially in the more oxidized pan-fired ones. 

One curiosity: I have been fascinated by the characterization of some green teas, including the sencha here, as tasting like asparagus. As I noted in my book "Three Basic Teas & How to Enjoy Them," I have yet to have a green tea that reminds me of asparagus, but clearly I may be alone (or in small company). That said, there is one compound in fig fruit that is common with asparagus, namely (E)-2-nonen-1-ol. It's in cucumber and melons, too, and has a "green" waxy odor. However, figs appear not to have any of the sulfur compounds found in asparagus and in green tea. Yet I can imagine that the asparagus-ness of the figs might complement the asparagus-ness of the sencha.

Pistachios have a number of compounds that activate the cool/cold receptors, at least one of which of which is shared with figs, namely limonene. However pistachios share a different set of compounds with green tea, in particular phenyl acetaldehyde.**

This fascinating chemical combines its "green" aroma with a chocolate/cocoa earthy one. It's a product of a Maillard reaction that occurs with mild heat, so would be more abundant the more roasted the tea (and the roasted pistachio, too). As Sara noted about the Woojeon tea: 

"When I sniffed the dry leaves my nose was instantly met with fresh meadow grass and something a bit surprising-chocolate!"

That would be the phenyl acetaldehyde! Interestingly the flavor of this tea veered away from the usual green grassy quality of the sencha towards the more roasty side. Activation of TRPV1 by the roast products dampens perception of the flavor of grassy chemicals that activate the cool/cold receptors 

What I think the balsamic vinegar in this mochi cake did was to cut the sweetness of the fig and mochi. Acetic acid in balsamico activates the sour responsive cells in our taste buds, which in turn decrease signals from sweet responsive cells and thus our perception of sweetness. 

It was another fascinating excursion into tea and food pairing by our ever-so-observant guides Georgia, Sara, and Jee. And don't forget, as Georgia concludes:

"Experimentation is important in tea and food pairing!" 

All of you out there, keep experimenting and sharing your results, and let's see whether we can figure out why pairings do (or don't!) work.  


* Andreia P. Oliveira, Luís R. Silva, Paula Guedes de Pinho, Angel Gil-Izquierdo, Patrícia Valentão, Branca M. Silva, José A. Pereira, Paula B. Andrade, Volatile profiling of Ficus carica varieties by HS-SPME and GC–IT-MS, In Food Chemistry, Volume 123, Issue 2, 2010, Pages 548-557, ISSN 0308-8146, https://doi.org/10.1016/j.foodchem.2010.04.064.
(http://www.sciencedirect.com/science/article/pii/S0308814610005212) 

** Hojjati, M., Calín-Sánchez, Á., Razavi, S. H. and Carbonell-Barrachina, Á. A. (2013), Effect of roasting on colour and volatile composition of pistachios (Pistacia vera L.). Int J Food Sci Technol, 48: 437–443. doi:10.1111/j.1365-2621.2012.03206.x. I should note here that another group appears not to have found phenyl acetaldehyde in pistachios: Ling, B., Yang, X., Li, R. and Wang, S. (2016), Physicochemical properties, volatile compounds, and oxidative stability of cold pressed kernel oils from raw and roasted pistachio (Pistacia vera L. Var Kerman). Eur. J. Lipid Sci. Technol., 118: 1368–1379. doi:10.1002/ejlt.201500336. The differences may be due to both treatment methods and cultivars.

Thoughts about Teforia's demise

As of today, Teforia no longer is in business or selling its products.* Teforia produced the highly celebrated tea making system ("Teforia Selective Infusion Profile System") that took the guesswork out of tea brewing, making it "easy," and produced a "perfect" cup of tea every time. According to World Tea News: 

"At World Tea Expo, Teforia was awarded 2016 Best Tea Industry Innovation Award and was named the 2017 Best (Electric) Tea Brewing Device. The innovative brewer, initially priced at more than $1,000, adjusted steep time, agitation, and temperature for premeasured [loose] tea in capsules sold online as Sips. These premium teas, from established growers such as Yamamotoyama in Japan, were delivered by subscription as fully recyclable and 90 percent compostable. The classic brewer could be programmed by smartphone to brew any tea."**

The Teforia Selective Infusion Profile System. Image from teforia.com  

The article in World Tea News cited four lessons to consider from this failure:

• Raising large VC rounds is no guarantee of future business success.
• Good product design is always a big driver for consumer adoption, but the underlying business fundamentals need to be sound for the venture to succeed.
• High-priced hardware appeals to early adopters and is critical in recouping development costs, but the number of early adopters, while influential, is always small. Pricing devices that people can afford, while balancing margins on the business side is essential to achieve scale.
• A closed ecosystem such as Teforia, Keurig and Nespresso can work to generate sustaining cash flow, but that’s assuming the consumables they are offering are unique and right-priced. Investors have pulled back from several similar beverage proposals.

What fascinates me is that they mention that the Teforia system is analogous to the Keurig and the Nespresso systems. Both of these systems make their coffee from premade, predosed containers to give you something simple, quick, with no thinking involved. In other words, coffee-on-the-go for people who don't have the time or perhaps even the desire to savor. There is nothing exquisite about these brews, but they serve their purpose.***

The price tag of Teforia was pretty stiff for the convenience of drinking tea as you might coffee: simple, quick, with no thinking involved—you can do as well with a tea sachet or a bottled tea, if you just want a cup of tea to go. 

The goals of the Teforia system, though, were to automate and make fool-proof the brewing of high-end teas, so the flavor would be perfect every time. Which it was.

Yet those of you who appreciate high-end teas will quickly say that the joys of sipping an exquisite tea lie in looking for and selecting the tea, in the aesthetics of pots, cups, and utensils, and especially in the ritual of the brewing process itself, not to mention in the surprise of tasting the results—no two brews are exactly alike, nor should they be.

So I believe that we should add to the four lessons laid out in World Tea News a fifth lesson, namely that preparing a cup of delicious tea is as much an art as a science, and requires a human hand and mind at every step of the way. Taking the human touch out of the process may yield a great flavor but not a great joy. 

* Here's a video of the Teforia system in action: https://www.youtube.com/watch?v=ixqM77riEOo
** http://worldteanews.com/news/teforia-closes-down
*** I'm working on a coffee book to go with my "Three Basic Teas & How to Enjoy Them," so have been diving deep into understanding coffee. By virtue of coffee's chemistry, the Keurig and Nespresso systems simply cannot give you a delicious coffee that you could savor the way you would savor tea.

Pairing teas at TexSom

Friend of Pairteas Jason McDonald sent me several emails a while back about a tea-pairing tasting he, Jeni Dodd, and Kyle Stewart carried out at TexSom, the big Texas sommelier event.* I followed up with emails to both Jeni and Kyle to learn more about the teas and the experience.

Here's what Jason said about the ingredients for the pairings:

"We used an aged Gruyère and an aged white cheddar. We used a tea from my farm [The Great Mississippi Tea Company - http://www.greatmsteacompany.com] that is best categorized as a dark oolong or a lightly oxidized black tea. We also used a dark tea from Nepal that Jeni supplied."

Jason McDonald with the cheese!

The general consensus was that Jason's oolong paired better with the cheddar than with the Gruyère. as I noted to Jason:

"The cheddar has a number of compounds in common with oolongs...don't remember whether you were still there when we smelled indole at WTE [World Tea Expo]. It has an animalic smell that is characteristic of oolongs, and contributes to oolong's complexity. In addition, both cheddar and oolongs have a number of compounds that have an almond quality [including benzaldehyde], and dimethyl sulfide, which has a marine smell. All of these compounds activate the warm receptors. The result is that the tea and the cheese will enhance each other." 

I should add that the fattiness of the cheese would turn off the hot receptors (TRPV1), so the flavors of the compounds that activate the warm receptors would be enhanced. 

Meanwhile, Jeni Dodd gave me more detail about her Nepalese tea, which she had cold-brewed overnight. She wrote:

"As for the Nepalese tea I used.  It is a black oolong from the Ilam (more specifically Maipokhara) region in the Eastern part of Nepal.  There are two main tea growing regions Ilam and Dhankhuta.  The oxidation of this particular tea is about 55-65%."

This tea is called Wild Sunset tea. As Jeni noted, here's why:

"My friend, whom I consider one of the best tea makers in Nepal, discovered a tea garden that had been growing wild for almost 30 years.  This garden was at the epicenter of the 2015 7.8 devastating earthquake.
My friend decided to leave the successful tea garden he had been at in order to cultivate this garden in order to bring economic stability back to this devastated region.  I requested to him to keep some of the wild growth since you cannot replicate 30 years of wild growth easily.  This tea from the first harvest of the wild growth after 30 years.  It is processed as a dark tea and right now has about 1 year of age on it."

Here's how Jeni describes the tea:

"It is smooth and full-bodied.  I find hints of cherry, but a cooked cherry, a sweeter cherry.  But the sweetness is balanced by a maltiness.  There is little to no astringency and the finish lingers.  The finishing notes are a bit smoky, a bit tobaccoey.  When you inhale, you find the cooling sensation that has been informed by the Eucalpytus trees growing in the area.  But there isn't a minty flavor.  There is a brightness to the tea, I think it must be that cooling effect.  But it is so nicely balanced and grounded by the maltiness."

To me this description is rich in hints about the chemical composition of the tea! 

First about the cooling sensation that Jeni says comes from eucalyptus trees going nearby: the chemical that gives eucalyptus its aroma is 1,8-cineol, which does bind to both the cool (TRPM8) and the cold (TRPA1) receptors. That's why it gives eucalyptus that cooling sensation when inhaled. 1,8-cineol has an herbal quality, but not very much a minty one. This compound will give a brightness to the tea, but, as I noted in my most recent post, cool sensations don't last long and can be overtaken by sensations provided by activation of the warm and hot receptors. Activation of these receptors lasts in the mouth, hence the long smoky tobacco-ey finish.

As for the sweetness, that probably comes from benzaldehyde and methyl salicylate. Depending on context, benzaldehyde can seem almond-like or cherry-like. It's my impression that the flavor shifts more to cherry in the presence of compounds that activate the "warm" (TRPV3) and "hot" (TRPV1) receptors.

So what about maltiness? and the smoky tobacco-ey finish? I am going to ask Jeni about the wood or coal that was used for baking or roasting the tea and for how long. Depending on the method, you will get the formation of compounds such as 2-ethyl furan, which has a classic malty flavor. That's a compound in Indian teas that gives them a rich maltiness. It, and a host of smoky and tobacco-ey compounds, all activate "hot" receptors.

It turns out that the Nepalese tea went well with the aged Gruyère. Its lower fat content meant that it didn't interfere with the ability to taste the subtleties of the tea derived from activation of TRPV1. As Kyle said:

"Cold-brewing leaves behind the catechins (astringency) and accentuates the top notes (fruity, floral) of this amazing oolong.  Without the astringency, the cold brewed oolong did not pair as well with the high-fat cheeses. The British used milk to soften the astringency of English Breakfast tea." 

Furthermore, as Kyle noted:

"The black raisin and green apple notes of the tea blended beautifully with the earthy, nutty and bosc pear notes of the Gruyère."

One of the compounds that gives Gruyère its nutty flavor is 2,6-dimethyl pyrazine. This compound is known to be in black tea, and is formed when the tea leaves are heated up during processing. My guess is that—given the color of the tea and Jeni's mention of smokiness—this tea was sufficiently baked/roasted to create this compound along with the malt flavored compounds.

Jason has the last word for this post:

"The teas made the cheese more intense in both cases. It seemed that it was a good pairing side by side because one of the cheeses went flat and the other became bold with both teas. It was also interesting that they were opposite of each other. So, it was a happy coincidence."

* According to Kyle "TexSom (Texas Sommelier) is an annual wine education conference held at The Four Seasons Resort in Dallas.  The Cultured Cup, which also sells coffee, has been a sponsor of this conference since its inception 12 years ago." 

Oolongs and fall fruits

Sara Shacket and her friends have been doing a series on tea pairings that is absolutely fascinating! The latest is about pairing oolongs with fruit, which you can find here:

http://www.tea-happiness.com/2017/10/tea-pairing-101-oolong-and-fruit.html

That page has links to the tasting notes by Georgia (http://www.notesontea.com/2017/10/tea-pairing-101-oolong-tea.html) and Jee (https://www.ohhowcivilized.com), who shared in the experience, and had similar takes on the results. Be sure to read all three blogs about the pairings, because each reveals a different aspect of the experience.

The teas were a Taiwanese Bao Zhong, which is lightly oxidized (typically around 10%), a classic Chinese Tie Guan Yin, and an equally classic Xiao Hong Pao (Little Red Robe), which was the most oxidized of the three.

What oxidation does is to shift the tea's flavor profile from vegetal and "cool" to more chocolatey, sweet, and "warm."

The three fruits were pear, plum, and persimmon, chosen because they are all fall fruits. It so happens that these three fruits also fall on a spectrum from "cool" to "warm." 

Teas from left to right, Bao Zhong, Tie Guan Yin, and Xiao Hong Pao.
Image from  http://www.tea-happiness.com/2017/10/tea-pairing-101-oolong-and-fruit.html

Here are the overall results, compiled from the three bloggers: 

The pear went reasonably well with the Bao Zhong, as you would expect because both tend to activate the "cool" receptors, though the Bao Zhong, described as only somewhat vegetal, would be less effective with pear than, say, a green tea. 

The Tie Guan Yin was happiest with the persimmon. The persimmon was described as very sweet—it was one of the persimmon cultivars, Fuyu, that is not naturally astringent.* Sara  described the sweetness as "cloying." A major volatile flavor compound in persimmon is benzaldehyde, which has a characteristic sweet almond/cherry quality with nutty/woody nuances, and to my nose can indeed be very cloying. Bennzaldehyde activates the warm to hot receptors. Turns out that the more roasted an oolong is the less benzaldehyde it contains—so it is not surprising that Tie Guan Yin would go better with the persimmon than the more highly roasted Xiao Hong Pao.**

Plums went best with Xiao Hong Pao. Plum cultivars vary tremendously in their composition, but one constant is the presence of lactones such as gamma-decalactone and gamma-dodecalactone.*** These lactones have a waxy fruity quality and tend to activate the warm/hot receptors.**** Interestingly, plums also have several compounds such as linalool and hexanol that activate the cool receptors. Sara, though not the others, noted that the plums went well with the lightly oxidized Bao Zhong: in contrast with the pear, "The plum turned out to be a better choice. Its sweetness worked well with the floral and savory notes, but didn't overpower the palate. The tart plum skin transformed the tea flavor, creating an interesting depth." My guess is that the depth came from the back and forth across the cool to warm receptors that each activated.

Which brings me to what I thought was the most fascinating observation with these pairings, about the pear and the Xiao Hong Pao, as described by Sara: 

"We had a strange experience with the pear- it seemed to erase the flavor of the tea, but then a moment later the tea lingered on the palate. Jee decided that the pear was similar to a palate cleanser, which was an interesting thought!"

It was indeed an interesting thought! What palate cleansers, such as the cool sorbet of classical French banquets, do is to reset the balance of the trigeminal system. Here's how this works:

The response of trigeminal receptors at the "hotter" end of the spectrum is slow-on slow-off, while the response of those at the "cooler" end is quick-on quick-off. Think about eating a chili-laced food. At first you may not think it's too spicy, but then the heat sneaks up on you—that's the slow-on. You reach for some ice water, which quickly cools down the burn—that's the quick-on. But wait a few seconds and the cool receptors turn off and the heat returns! Signals from the "hot" receptors were just suppressed, but because they are slow-off, they were still active when the "cool" receptors had stopped sending signals to your brain. Remember that the sequence here is important.

This is exactly what was happening with the pear and the Xiao Hong Pao. This highly oxidized tea is full of chemicals that activate receptors at the hotter end of the trigeminal spectrum, while the pear activates receptors at the cooler end. Sip the tea, and the hotter end is activated. Bite into the pear, and the tea disappears. Wait a little, the pear flavor vanishes and the tea effect (which has been there all along) returns.

I've not mentioned here that all three bloggers found that honeycomb went well with all the teas, and managed to cover up what I would call the disagreements among the tea and fruit flavors. That will be a discussion for another blogpost.

And to find out more about the trigeminal system and what it means for tea and tea pairing, find my book "Three Basic Teas & How to Enjoy Them" at Amazon!

* Lyon, B. G., Senter, S.D. and Payne, J.A. (1992), Quality Characteristics of Oriental Persimmons (Diospyros kaki L. cv. Fuyu) Grown in the Southeastern United States. Journal of Food Science, 57: 693–695. doi:10.1111/j.1365-2621.1992.tb08074.x

** For the chemical profiles of panned and unpanned oolongs, go to: Sheibani E, Duncan SE, Kuhn DD, Dietrich AM, Newkirk JJ, O’Keefe SF. Changes in flavor volatile composition of oolong tea after panning during tea processing. Food Science & Nutrition. 2016;4(3):456-468. doi:10.1002/fsn3.307. You can find the article online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4867765/.

*** Y. H. Hui, Feng Chen, Leo M. L. Nollet. Handbook of Fruit and Vegetable Flavors. John Wiley and Sons, 2010. Also, go to http://www.flavours.asia/uploads/7/9/8/9/7989988/flavor_of_plums.pdf

**** Incidentally osmanthus, which goes so well with Tie Guan Yin, also has these lactones.