Chinese Green Tea

1. Origin of Green Tea

Time of Origin
There are various theories about the specific time of origin of green tea. Some believe that it can be traced back to more than 3,000 years ago in the Ba region (now northern Sichuan and southern Shaanxi). According to “Hua Yang Guo Zhi – Ba Zhi,” people in the Western Zhou period (1046-771 BC) had begun to cultivate tea in their gardens. Others suggest that green tea originated in the Tang Dynasty due to the gradual improvement of its production techniques and the popularity of steaming methods. There is also a legend that the origin of green tea is related to Shen Nong, who discovered the medicinal value of tea after accidentally consuming poisonous plants and detoxifying himself with tea.

Place of Origin
Green tea is native to China, and the earliest known production area is believed to be the Ba region. Additionally, Mount Meng in Sichuan is also considered one of the birthplaces of tea cultivation and manufacturing. Over time, the cultivation of green tea expanded to various parts of China, as well as to Japan, Thailand, North Korea, and South Korea.

Historical Development

Ancient Times
During the Spring and Autumn period and the Warring States period, people began to consume green tea as a beverage for sacrificing to ancestors and entertaining guests. In the Qin and Han dynasties, the production method of green tea gradually matured, and it became a delicious and medicinally valuable drink. During the Jin, Southern and Northern Dynasties, tea cakes made from loose tea leaves and rice paste were developed for easier storage and transportation.

Tang and Song Dynasties
In the Tang Dynasty, the technique of steaming green tea and pressing it into cakes was further refined, and steaming became popular. During the Song Dynasty, steamed loose green tea emerged, and tea began to be presented as a tribute. In the Ming and Qing dynasties, the practice of roasting loose green tea arose. The process of high-temperature killing of enzymes, rolling, re-roasting, and baking until dry is very similar to modern methods of roasting green tea.

Modern Times
Since modern times, the production and trade of green tea have experienced stages of prosperity, decline, and recovery. Nowadays, green tea has become one of the most produced types of tea in China, with a rich variety of species and famous brands, and significant economic value.

2. Characteristics and Production Process of Green Tea
   Green tea is a type of tea that undergoes no fermentation, and its production process mainly includes picking, enzyme inactivation (or “killing green”), rolling, and drying. During the enzyme inactivation step, high temperatures are used to deactivate enzymes in the tea leaves, preserving their green color. This distinguishes green tea from other types of tea such as black tea and oolong tea. Green tea is characterized by its clear broth and green leaves. The dry tea leaves have a lush green color, and when brewed, the tea liquor is clear and bright. The leaves at the bottom of the cup are bright green, the aroma is fresh and high, and the taste is pure, refreshing, and astringent.

Production Process of Green Tea

2.1 Picking
Picking is a crucial first step in the processing of green tea and a determinant of the tea’s basic quality. Factors such as picking time, leaf age, quantity picked, and picking method all affect the quality of the tea. Early spring is the primary period for picking green tea, typically between late February and mid-March. During this time, the tea leaves are tender and contain various beneficial substances, particularly high levels of tea polyphenols in the young leaves. The picked tea leaves should be tender, delicate, and plump, with neatly arranged, fresh, and intertwined stems and leaves.

2.2 Enzyme Inactivation (“Killing Green”)
Enzyme inactivation is a key step in green tea production. It aims to deactivate enzymes in the tea leaves using high temperatures, preserving their green color and emitting a unique fragrance. There are three main methods of enzyme inactivation:

● High-temperature inactivation: Fresh tea leaves are heated in high-temperature steam, typically above 200℃, for about 1 minute. This method preserves the bright green color of the tea leaves and evaporates their moisture. For example, the temperature for “killing green” in West Lake Longjing tea can reach 230℃.

● Low-temperature inactivation: Fresh tea leaves are heated at temperatures below 63℃ for about 1 to 2 minutes. This method retains the fresh green color and nutrients of the tea leaves.

● Oxidation-reduction inactivation: Fresh tea leaves are heated and treated in nitrogen oxide for about 10 minutes. This inactivation method preserves the natural fresh green color of the tea leaves.

2.3 Rolling
Rolling is an important step in green tea production. It aims to shape the tea leaves through external forces, disrupt the cell structure, squeeze out tea juice, adhere it to the leaf surface, enhance tea aroma, and lay the foundation for roasting into strips. There are two main rolling methods: manual rolling and mechanical rolling.

● Manual rolling: Commonly used in the production of high-end green teas, it involves various rolling techniques such as shaking, pulling, squeezing, and swinging, as exemplified in the “Ten Techniques” of West Lake Longjing.

● Mechanical rolling: Used in the industrial production of green tea, it employs mechanical force for rolling, resulting in higher efficiency.

2.4 Drying
Drying is the final step in green tea production, aimed at further removing moisture from the tea leaves, enhancing aroma, and stabilizing quality. There are two main drying methods:

● Hot air drying: Performed at higher temperatures, typically around 80-90℃, for a shorter duration.

● Oven drying: Conducted at lower temperatures, generally around 50-60℃, for a longer time to maintain the original taste and color of the tea.

2.5 Classification and Packaging
After drying, green tea undergoes screening and classification based on size, shape, and impurities. It is then packaged according to different grades to ensure quality. Packaging materials for green tea typically include aluminum cans, fresh-keeping bags, and vacuum bags to maintain the tea’s aroma and taste.

2.6 Unique Craftsmanship
Apart from the basic production process, different types of green tea have their unique craftsmanship. For instance:

● West Lake Longjing: A set of distinctive “Ten Techniques” frying process has been developed during the frying stage.

● Mount Meng Tea: Known for its “red pot enzyme inactivation, high to low temperature, three frying and three rolling” process, resulting in a unique combination of color, aroma, taste, and shape.

● Tunxi Green Tea: The production process is complex, involving 37 steps and hundreds of variations, requiring 14 days to complete.

3. Types and Famous Brands of Green Tea

● Classification Methods: Classification based on origin, shape, production process, etc.

● Famous Varieties:

○ Longjing (West Lake Longjing): Produced around West Lake in Hangzhou, characterized by a flat and smooth shape, lush green color, elegant aroma, clear and bright liquor, and a mellow and refreshing taste.

○ Biluochun: A specialty from the Taihu Lake region in Jiangsu, known for its curly shape resembling a snail, silvery green color with hidden emerald hues, rich and lasting aroma, clear and green liquor, and a fresh and sweet aftertaste.

○ Zhuyeqing: Originating from Sichuan, it resembles bamboo leaves in shape, with a lush green color, fresh aroma, yellow-green and bright liquor, and a refreshing taste.

○ Anji Baicha: Although its name contains “Baicha” (white tea), it is actually a green tea from Anji, Zhejiang. It is characterized by a tender green color, fresh aroma, clear and slightly yellow liquor, and a refreshing taste.

4. How to Appreciate Green Tea

4.1 Observing the Appearance

● Stripes: Observe whether the tea stripes are tight, fine, heavy, and solid, with exposed tips. Different varieties of green tea have distinct shapes. For example, Longjing is preferred for being flat and straight with no bending at the tip and a delicate body, while Maofeng is favored for being slender with slightly curved tips.

● Color: Green tea should have a tender green and fresh color. Yellow, dull, or withered colors indicate poorer quality. Color should be observed in terms of dry tea color, liquor color, and leaf bottom color.

● Purity: The tea should be free of impurities such as tea stalks and dust. High purity indicates better quality.

4.2 Smelling the Aroma

● Type: Green tea has a diverse range of aromas, such as bean, olive, orchid, and chestnut. High-quality green tea should have a strong and lasting aroma that is pleasant and refreshing.

● Purity: The aroma should be pure without any off-odors. Smoky or burnt odors indicate poor quality.

● Timing: The aroma can be smelled before brewing (dry tea aroma), during brewing (cup aroma, lid aroma), and after brewing (tea bottom aroma).

4.3 Tasting the tea

● Concentration: The concentration of the tea should be moderate, neither too strong nor too weak.

● Freshness: Good green tea should taste fresh, mellow, full-bodied, and sweet with a lingering aftertaste. If it tastes bitter, astringent, or has a coarse, grassy, or unusual flavor, then the quality is poor.

● Tasting method: Do not take too much tea into your mouth. Rotate the tea in your mouth occasionally to fully experience its flavor.

4.4 Observing the tea color and tea leaves

● Tea color: The best color for green tea is bright and tender green, followed by greenish bright and then yellowish green. The tea should be clear without any turbidity, floating objects, or sediments.

● Tea leaves: The tea leaves (tea residue) after steeping should have a high proportion of tender buds, soft texture, bright and tender green color, and uniform shape. Poor quality tea leaves are hard, thin, mixed, uneven in size, and have a disharmonious color.

4.5 Understanding the origin and picking time

● Origin: Green teas from different origins have different quality characteristics. For example, Zhejiang green tea has a strong bean fragrance and a smooth taste, while Sichuan green tea has a strong tea flavor with an earthy taste, and Yunnan green tea has large strips with a strong woody aroma.

● Picking time: Pre-Qingming tea (picked before the Qingming Festival) is famous for its fresh and delicious taste, which is smooth without bitterness or astringency. Post-Qingming tea has a higher cost performance but slightly inferior taste, while summer tea may have insufficient aroma due to excessive rain and may have a grassy taste.

5. Method for brewing green tea

● Preparation tools: Select suitable tea sets (such as porcelain or glass lidded bowls, fair cups, and tasting cups), water quality (preferably soft water), and water temperature (generally 80-85°C).

● Amount of tea: Adjust according to personal taste and the size of the tea set, generally 3-5 grams of tea per 100 milliliters of water.

● Brewing steps:

○ Warming the cups: Preheat the tea set with hot water to enhance the aroma of the tea.

○ Adding tea: Gently place the tea into the tea set.

○ Pouring water: Slowly pour hot water along the edge of the tea set, avoiding direct impact on the tea leaves, to ensure even heating.

○ Waiting: Adjust the steeping time according to the tea type and personal taste, generally 30 seconds to 1 minute for the first steep, and can be appropriately extended for subsequent steeps.

○ Pouring the tea: Pour the tea into the fair cup and then distribute it into the tasting cups to ensure an even distribution of tea in each cup.

○ Tasting: Follow the steps in the tasting art to carefully savor the color, aroma, taste, and shape of the green tea.

○ Rebrewing: Green tea can generally be rebrewed 2-3 times, and the steeping time can be appropriately extended each time.

6. Green tea and health

Green tea is rich in nutrients such as tea polyphenols, catechins, chlorophyll, caffeine, amino acids, and vitamins. These components have special effects on anti-aging, cancer prevention, cancer resistance, sterilization, and inflammation reduction. Modern scientific research also shows that green tea has various health benefits such as lowering blood lipids, weight loss, antioxidation, and lowering blood pressure.

It is recommended to consume it in moderation every day, especially after meals or during work breaks. Pregnant women and patients with special diseases should consult a doctor.