Tea plants (Camellia sinensis) produce astringent tasting polyphenols called tannins, and tea brew generally contains somewhere around 0.01% tannin. There are thousands of different tannins and at least two thousand of them are know to have a flavon structure and thus called flavonoids. One type of these flavonoids, and the most prevalent in tea, is a group of flavonoids called catechins. Catechins have a bitter / astringent taste, and are believed to be the primary reason tea has been found to have many health benefits (such as reduction in ischemic heart disease, cancer resistance, lowering blood cholesterol, and help controlling allergy). Much of the catechin in tea leaves convert into theaflavin, and thearubugen if the leaves are oxidized (turned into black tea as opposed as kept as green tea). This conversion is responsible for the color change in the teas.
Don't be to quick to switch to green tea for the the health benefits though. Theaflavin and thearubugen are pretty much just strings of catechins and are being found to have the same activities as lone catechin molecules. Tea brew also contains about 0.002% caffeine, which also has a bitter taste.
Pu-erh, aka. Pu-er or P’uerh (po-lay or bo-lay in Cantonese) is a special tea that got its name from the town of Pu-erh in the southern part of the Yunnan province of China. The Yunnan province of China is on the Tibet border, and Pu-erh was the largest market for tea trade. The production of Pu-erh is unique and has been a state secret until relatively recently. Pu-erh is plucked from large-leafed tea trees propagated from trees as old as 1800 years, and of the primitive Da Yeh variety. The trees can be plucked almost year round and grow at high altitude. Though the exact procedure for processing the tea is still sketchy for outsiders, as I understand it, the leaves are then lightly pan-fired then dried in the sun (where they semi-oxidize), then lightly steamed, and pressed into forms. The tea is sometimes loose, but is normally pressed into bricks, circular cakes, or hand-formed tuo cha (birds-nest shaped). The tea is then aged in humid caves within the region which cause the leaves to slowly re-oxidize and develop a thin layer of mold (Pu-erh is the only tea that is purposefully aged).
The brewed tea is full-bodied, musty, earthy, often with a deep maltyness, and a long finish. Good Pu-erhs are smooth and sweet, while poor grades are often harsh and bitter. The aging process makes the tea richer and smoother while causing the tea to slowly oxidize darker and darker. Many Pu-erhs range in age from 5-35 years, but it is not uncommon to find a 60 year old. I often recommend it for coffee drinkers who are interested in expanding to tea because it is so full-bodied. The tea even looks like coffee as it is dark brown / black but with a red tinge. There is also green Pu-erh which has a slightly different processing method.
The first consumption of Pu-erh tea dates back to the Shang and Zhou dynasties (1066BCE – 221BCE). The tea was originally consumed and prized for its health benefits and medicinal value, and the bricks were used for currency. In addition to all the health benefits of most teas, Pu-erh has been shown to increase the HDL / total cholesterol ratio (a good thing). Pu-erh is also a digestive aid (very nice after a big meal), and is popular in Europe as a diet aid. Preparation methods for Pu-erh vary. Tibetans are know to boil it overnight to brew, while some Chinese brew it for ten to twenty successive steepings of about 3 minutes each (purple clay (Yixing) teaware recommended). I recommend steeping with water right off the boil for between five and ten minutes. The steeping time varies to taste and one should experiment with different times because 1) the tea can taste quite different brewed for different lengths, and 2) Then you’ll have to try it several times and Pu-erh is know to take some getting used to. We have a very nice Pu-erh at the shop formed into mini tou-cha if you are interested in trying this unique and mysterious tea.
Oolong tea is a term used for tea that is semi-oxidized. Green, oolong, and black tea all come from the same plant, Camellia sinensis (the tea plant), the difference between them is their level of oxidation. Green tea is unoxidized, oolong tea is semi-oxidized, and black tea is fully oxidized. Oxidation occurs naturally when cells of the tea leaves are ruptured, thus releasing enzymes that happen to catalyze oxidation of the tea leaves. The cells are most often ruptured by shaking, raking, or rolling the leaves. Oxidation of the tea leaves is stopped by destroying the enzymes. The enzymes are most often destroyed by denaturing them by steaming or pan-firing at high temperature. So if one wants a green tea, one would pick the tea leaves and steam or fire them to prevent any oxidation. If one desired black tea, one would pick the leaves, rupture cells in the leaves to induce oxidation (most often by rolling), let the leaves oxidize for several hours, then fire them to dry the leaves and halt oxidation (often done in large woks or ovens). So if one wants a oolong tea, one would pick the leaves, rupture just a certain percentage of the cells in the leaves to induce slow and controlled oxidation (often by repeated cycles of gently shaking in bamboo baskets and then allowing them to slowly oxidize and dry in the shade), achieve the desired level of oxidation ( can vary from 20% for a greener oolong to 60% for a classic Formosa (Taiwanese) oolong), then quickly fire them to dry the leaves and halt oxidation (often pan-fired). Preparing oolong teas is obviously more time consuming and difficult.
Because oolong tea is semi-oxidized, it has taste characteristics of green and black teas, but it also has flavors of its own. I would encourage anyone who appreciates tea to try a few oolongs. We offer several at the shop and we'd be happy to help you select from among them.
The following are some basic tea tasting terms.
Astringency: A live, pungent sensation on the tongue and gums. Astringency is not to be confused with bitterness, which is undesirable. Astringency gives tea its refreshing quality.
Body: The tactile impression of thickness, or viscosity in the mouth. Teas may feel light-, medium-, or full-bodied. Bouquet: A complex flowery or perfumy aroma. Brisk: A lively flavor found in high quality tea, as opposed to flat.
Character: The aroma and flavor that can be associated with country, region, district, or even garden of origin.
Citrusy: A lemon, grapefruit, or orange rind flavor.
Complex: A flavor or aroma with many dimensions, as opposed to simple.
Fruity: A sweet, fruity flavor, such as peaches, apricots, grapes or currants.
Malty: A sweet, malted barley flavor.
Pungent: Astringent with a good combination of briskness and strength.
Self-Drinking: Term applied to tea that has good quality and flavor balance, and does not need blending.
Smoky: Ranging from subtle aromas of wood smoke or ash, to a very strong scent of smoke.
Toasty: A pleasant baked or biscuity aroma.
Vegetal: A general characteristic of green teas, ranging from grassy to herbaceous to seaweed.