Tuesday, June 5, 2007

The ABC's of T

Tea 101

When I say tea, I don't mean just anything boiled in water that's drinkable. Tea is often confused with these herbal decoctions, a.k.a. herbal teas, herbal infusions, "teasanes," Wildberry Zinger, etc. Nope... I'm talking about that one divine plant, scientifically classified as Camellia sinensis. Camellia is the genus, and sinensis, the species, means "Chinese" in Latin. And not just any part of the plant can be used to make the #1 consumed beverage in the world (after water), only the leaves. Here are some other interesting facts about the plant:

  • Camellia sinensis is native to tropical regions of southeast asia, preferring heavy rainfall and acidic soil conditions.
  • The plant has a lifespan of more than 100 years!
Tea History (2737 B.C. - present)

Legend has it that Chinese emperor Shen Nung (which means "divine healer") was boiling his water to drink, and the breeze blew some leaves from a nearby bush right into his imperial cup. Being that he was a great teacher of agriculture and herbology, he decided to taste the color-infused water. Noticing the relaxing yet uplifting effects, and increased sense of well-being, he insisted that the others try it. And so tea was born.

In China, they originally called tea "cha." This is the most commonly used name across all of China. But when tea first reached Europe it came from the Fujian province of China, where the local Fukienese dialect calls it "tey." Countries such as India, Russia, and Turkey use the word "cha" since they were introduced to tea by traders traveling overland from China along the Silk Road.

Tea Biochemistry

The graphic to the right shows an approximate breakdown of what biochemicals compose the tea leaf. This was compiled from information in a very good article on the biochemistry of tea. The slices of this tea-pie that most tea-drinkers will pay attention to are the polyphenols (in lavender), which are potent anti-oxidants, and caffeine (in orange), a potent pick-me-up. Caffeine imparts a strong cup of tea with its ability to energize, increase alertness, and elevate your mood. Anti-oxidants have shown to be very beneficial for ones health, including the ability to reduce the risk of cancer! While it is good to analyze the individual constituents of tea and the properties they tout, it is important to remember that the act of focusing on one aspect of the plant can make us lose sight of its complexity in a greater context. These individual constituents of tea are what they are because of their interaction with a multitude of other factors during the plant's evolutionary history. This includes the complex network of chemical reactions that take place in the leaves as they absorb the sun's radiant light, breathe carbon dioxide and aspire oxygen, the complex nutrient exchange that takes place at the roots, and the ecosystem or network that the plant is ecologically embedded in, depending on and providing for a multitude of organisms--both of the micro and large type. A large organism of key importance here is man, since the plant has been subject to artificial selection, meaning humans have selected for the qualities in tea that are most desirable during thousands of years of practicing its cultivation. It is also important to gain insight as to how these ecological networks, their components and interactions have changed over time and continue to do so as evolution unfolds. This holistic perspective on tea is something that reaches beyond the scope of words, and can only be tapped into by experiencing tea itself, a one-on-one conversation between you and the plant's brewed essence--a dialog that many great sages and philosophers have no doubt had during epiphanous moments of inspiration. Lao Tzu drank tea as he wrote the Tao Te Ching in the 6th century BC, calling it the "elixir of immortality."

A Tea Prism

Just like light through a prism, we can obtain an entire spectrum of teas from the one plant--from white tea to black tea and everything in between. First about the varieties of Camellia sinensis. There are two main varieties, the Assamese variety (Camellia sinensis var. assamica) and the Chinese variety (Camellia sinensis var. sinensis). The Assamese variety is a tree that grows quite tall, about 6-20 meters, and has large leaves. The Chinese variety is a small bush that reaches about 3 meters in height, and has smaller leaves that are more resistant to cold temperatures. Since the tea exportation industry has had a long time to develop on a worldwide scale, both of these main varieties are found in all of the top tea producing nations. In the internationally known tea plantations of Darjeeling, Assamese varieties are grown at lower altitudes, and Chinese varieties at the cold, higher altitudes. As you might imagine, the two main varieties of tea branch off into hundreds of classified varieties. Interestingly however, there appears to be more genetic variation among the Chinese varieties than the Assamese varieties, perhaps because China was the first country to value tea as a beverage and have been cultivating it longer and into more diverse geographical regions.
Besides genetics, many factors determine the quality of the harvested tea leaf. Altitude influences the amount of chlorophyll or green pigmentation in the leaf. There are two primary pickings of the leaves, once harvested in early spring and again in early summer. The first flush is generally considered superior, although this is not true for some varieties and climate conditions. Some plants are even harvested during the cold and dry months of winter such as in the case of plantations of southern India.
While the actual plant which the tea leaves are picked from definitely has a lot to do with your resulting brew, there are many ways to process the leaves which can produce a whole gamut of flavors. This is how a tea leaf becomes either white, yellow, green, oolong, red, or black tea! The primary steps in processing include: picking, wilting, bruising, oxidizing, shaping, drying, and curing. Whether or not or to what degree the leaf undergoes each of these steps will ultimately determine the resulting type of tea.

  1. Wilting is a primary drying stage during which the leaf loses water weight and suffers very light oxidation.
  2. Bruising releases some of the leaf's juices to change the taste profile of the tea as well as promote faster oxidation.
  3. Oxidation, also known as fermentation (incorrectly, since no microorganisms are involved), is the most influential step in determining the tea's ultimate biochemical contents and thus flavor. The green leaves are left in a dark room and turn a darker color as they absorb oxygen, undergoing enzymatic reactions that break down the chlorophyll and in turn produce tannins. Green teas are not at all oxidized, oolongs are only partially oxidized, and black teas are fully oxidized.
  4. Shaping can include hand or machine-rolling the leaves--lengthwise into strips, into spirals or pellets, or tying them together into balls or other elaborate display-tea shapes.
  5. Drying is the last step for most teas, and can be accomplished by panning, air-drying, sun-drying, or baking.
  6. Curing is a secondary-fermentation and aging process used to produce "pu-erh" teas.
Here is a graphic that shows six types of teas and how they are differently processed:

White tea is the least processed type of tea. New growth leaves are used, and therefore don't have very much green pigmentation. It is baked to deactivate oxidative enzymes and thus halt oxidation. The leaves are then shaped and dried. Fine white tea is so unprocessed that it still has the small hairs on the leaves. White tea is a specialty of the Fujian province of China. White tea differs from green tea in their proportions of antioxidant compounds, and white tea has more caffeine, as well as more anti-viral and anti-bacterial properties than green tea.
Yellow tea is similar to white and green teas, but undergoes a slower drying phase to give it a unique flavor. It is not very popular and may be difficult to obtain.
Green tea is widely popular in China, Japan, Taiwan, and Morocco. It is becoming increasingly popular in the Western world, as it has relatively recently been discovered to have wide-ranging health benefits. The mature tea leaves are heated quickly after harvesting by either steaming (following Japanese tradition) or dry heating in pans (as the Chinese do) to halt oxidation. There are thousands of green tea varieties to be appreciated for their unique intricacies.
Oolong tea is labor intensive and often very delicately produced. The leaves are first wilted, then bruised on the edges to enhance oxidation. Next the leaves are 30-70% oxidized during 2-3 days before they are heated to halt the oxidation, and finally dried. Oolong literally means "black dragon" in Chinese.
Black tea is the most commonly drunk tea in the Western world, including the U.S. and Europe. It is a fully oxidized tea. Fully oxidized tea is known as red tea in China, although the Chinese processing techniques don't use the CTC method of bagged black teas. CTC stands for "Crushing, Tearing, and Curling" the tea leaves, a method discovered to allow bulk processing since it is done by machine. The leaves are passed through cylindrical rollers with lots of little teeth on them, precisely to crush, tear, and curl the leaves, yielding small leaf pieces that are quicker brewing and able to be more efficiently packed than loose leaf tea. While this method makes massive tea production more cost-effective and dominates the tea export market, it compromises the flavor that is obtained by traditional processing methods.

Brewing that perfect cup

From "high tea" to "kung fu" tea, there are many ways to make and enjoy the beverage after the leaves have been obtained. Bagged tea is convenient, quick, and easy, and more commonly found in the Western world. For a quick caffeine boost, with milk and sugar, and off to work, or so that everyone can choose how they like their cup of tea, since bags can go directly in the cup. Loose leaf tea is what has traditionally been used in China, and is slowly becoming more popular in the West as more people are discovering the wonders of tea and all of its subtleties. Due to the large leaf size, it is difficult to brew loose leaves in the cramped space of a bag, so many techniques are used to brew and then filter the leaves so they don't end up in your cup. Of the most interesting is "gong fu" or "kung fu" tea. Yes, the Chinese characters are the same as the butt-kicking "kung fu" that seems so different from a relaxing cup of tea. But the concept applies to both art forms--the martial type and the tea making type--and denotes "skill from practice." Every step in preparation is carefully and artfully executed with a series of utensils that are also artfully crafted. Temperature is a very important consideration here. The perfect temperature water is used not only to brew the tea, but to clean the cups before and between brewings, and to warm the teapot inside and out. The tea is multiply brewed, the second brewing often considered the best of all. It is also important to consider the flavor change based on brew time, brew round, and where the water sits in the pot, and for this reason the tea is poured into the cups in a circular fashion. The last drops of tea from the pot are so valued to even have a special name, and should be shared among each cup. Careful attention to the necessary overflowing and spilling of water is also key to an artful presentation. "Gong fu cha" is a beautiful, almost ritualistic ceremony for which there are even regional and national competitions in China.
Brewing that perfect cup definitely starts with a clean source of water, and important to consider is tea quantity, water temperature, and brewing times. Black, bagged tea is generally brewed with boiling water (230° Fahrenheit/100° Celsius) for 3-5 minutes. Loose leaf oolong and green teas are brewed with steaming-hot water (~180-190° Fahrenheit/82-88° Celsius) for 20 seconds-2 minutes, extending the time a bit with each brew. White teas are brewed at this less than boiling temperature for a longer period of about 3-5 minutes, since it doesn't get bitter. There is a lot of varying opinion on how to brew tea, and the best way to learn is by experimenting for yourself.

The best way to learn, and to truly enjoy your tea, is to forget everything you may have learned here, since tea can only be poured into an empty cup.

"Empty yourself of everything.
Let the mind become still.
The ten thousand things rise and fall while the Self watches their
They grow and flourish and then return to the source.
Returning to the source is stillness,
Which is the way of nature."
-Lao Tzu
Tao Te Ching

1 comment:

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