1. Pre-class Introduction

This course focuses on the basic knowledge of China's six major tea categories. The core content is the tea classification system established by tea industry experts in 1979. It will systematically analyze the characteristics, representative varieties and process key points of green tea, white tea, yellow tea, oolong tea, black tea and dark tea, helping learners establish an overall understanding of Chinese tea categories.

2. Chinese Tea Classification System

In 1979, based on processing technology and fermentation degree, tea industry experts standardized nearly 1,000 kinds of tea in China into six major categories, namely: Green Tea, White Tea, Yellow Tea, Oolong Tea, Black Tea, Dark Tea. This classification system remains the mainstream industry standard to this day.

3. Detailed Explanation of the Six Major Tea Categories

(1) Green Tea

Representative Varieties: Longjing (Hangzhou, Zhejiang), Biluochun (Suzhou, Jiangsu), Taiping Houkui (Anhui), Liu'an Guapian (Anhui), Zhuyeqing (Sichuan)

Core Characteristics: Unfermented (fermentation degree 0%). It retains the natural green color of tea leaves through high-temperature processes. The tea soup is clear and bright, with a fresh and sweet taste.

(2) White Tea

Main Production Areas: Fuding, Zhenghe, Songxi, Jianyang (Fujian Province)

Classification Standards:

Baihao Yinzhen: Picked from single buds, the highest grade

Bai Mudan: One bud with two leaves, with a quiet aroma

Shoumei: One bud with multiple leaves, relatively thick leaves; high-quality Shoumei with high bud content is called "Gongmei"

Core Characteristics: Slightly fermented (fermentation degree 5-10%). The process is simple, relying only on natural withering and dehydration by sunlight or wind to retain the original form of tea leaves to the greatest extent.

(3) Yellow Tea

Industry Status: The rarest and most niche category among the six major tea categories, known as the "tea category that is about to disappear"

Representative Varieties: Mengding Huangya (Sichuan), Junshan Yinzhen (Hunan), Wenzhou Huangtang (Zhejiang), Weishan Maojian (Hunan), Daqingye (Guangdong)

Core Characteristics: Lightly fermented (fermentation degree 10-20%). Its appearance is similar to green tea but with a yellowish tint. The tea soup is bright yellow, with a sweet and mellow taste like sugarcane and water chestnut soup.

(4) Oolong Tea

Historical Status: The latest emerging variety among the six major tea categories, with the most complex process

Four Major Production Areas and Representatives:

Northern Fujian Oolong: Centered on Wuyi Rock Tea (Dahongpao as the representative)

Southern Fujian Oolong: Tieguanyin (in granular form) as the representative

Guangdong Oolong: Fenghuang Dancong, with a prominent and unique aroma

Taiwan Oolong: Dongding Oolong produced in the Central Mountain Range

Core Characteristics: Semi-fermented (fermentation degree 30-60%). Its aroma is the richest among the six major tea categories, including floral, fruity, roasted and other types.

(5) Black Tea

International Status: The most consumed tea category in the world

Morphological Differences:

International Mainstream: Broken tea (mainly in India, Sri Lanka, European markets)

Chinese Characteristics: Whole-leaf tea (retaining the complete form of tea leaves, such as Yunnan Dianhong)

Core Characteristics: Fully fermented (fermentation degree 80-95%). The tea soup is bright red with a golden rim (the more obvious the golden rim, the better the quality). High-quality black tea has an orange-like fruity aroma.

(6) Dark Tea

Representative Varieties: Yunnan Pu'er Tea (ripe Pu'er), Ya'an Zangcha (Sichuan), Anhua Dark Tea (Hunan), Laoqingzhuan (Hubei)

Core Characteristics: Post-fermented (fermentation degree 100% + microbial participation), commonly in the form of pressed tea cakes. The tea soup is bright reddish-brown, with a rich and mellow taste. High-quality dark tea has a milky and aged aroma.

4. Core Principles of Tea Classification

(1) Classification Basis: Fermentation Degree

The six major tea categories form a complete gradient according to the fermentation degree, changing progressively from "unfermented" to "post-fermented":

Green Tea: Unfermented (0%)

White Tea: Slightly fermented (5-10%)

Yellow Tea: Lightly fermented (10-20%)

Oolong Tea: Semi-fermented (30-60%)

Black Tea: Fully fermented (80-95%)

Dark Tea: Post-fermented (100% + microbial participation)

(2) Key Processes of the Six Major Tea Categories

Green Tea: The core is "fixing" (stopping enzyme activity at high temperature), divided into stir-fixing (Longjing), steam-fixing (Japanese Sencha), bake-fixing (Huangshan Maofeng), and sun-fixing (some Yunnan green teas). It retains the fresh green state of tea leaves through high temperature.

White Tea: The core is "withering" (natural dehydration), without stir-frying or rolling. The process is completed when the water content drops to 8-10%, retaining the original flavor to the greatest extent.

Yellow Tea: The core is "yellowing" (moist heat oxidation). After fixing, when the tea leaves are 70-80% dry, they are sealed and piled up for slow oxidation through moist heat to form the "yellow leaves and yellow soup" characteristic. The difficulty lies in the precise control of the yellowing time—too short will result in astringency, too long will lead to over-fermentation.

Oolong Tea: The core is "bruising" (mechanical damage-induced fermentation). By shaking the tea leaves to make the leaf edges collide and break, the polyphenols at the broken parts undergo enzymatic oxidation, forming the "green leaves with red edges" characteristic. The fermentation degree is controllable (20-70%).

Black Tea: The core is "rolling and fermentation" (full enzymatic oxidation). There is no fixing step, allowing polyphenols to be fully oxidized to form theaflavins and thearubigins, just like a "car without braking" with complete fermentation.

Dark Tea: The core is "piling" (microbial post-fermentation). After fixing, the rough tea is sprinkled with water and piled up, covered with linen to maintain a temperature of 60-65℃ and humidity, and transformed by microorganisms such as Aspergillus niger. Different from other tea categories with "pre-fixing fermentation", it belongs to "post-fixing fermentation".

5. Sensory Characteristics Comparison of the Six Major Tea Categories

(1) Tea Soup Characteristics

Green Tea: Clear and bright, showing a tender green color (e.g., Longjing)

White Tea: Similar to green tea but with downy turbidity. Baihao Yinzhen and Bai Mudan have obvious downy characteristics, with a "down aroma" (similar to the smell of raw rice)

Yellow Tea: Bright yellow and transparent, with a sweet and mellow taste

Oolong Tea: Great variety differences—Dahongpao is bright orange-red, Tieguanyin is bright golden yellow

Black Tea: Bright red with a golden rim (Dianhong is typical)

Dark Tea (Ripe Pu'er): Bright reddish-brown, rich but not bitter

(2) Taste Characteristics

Green Tea: Fresh and sweet, Longjing has a fresh bean aroma

White Tea: Quiet floral aroma + sweet and moist taste, with down aroma in the aftertaste

Yellow Tea: Sweet and mellow like sugarcane and water chestnut soup or corn water

Oolong Tea: The most intense aroma—rock tea has a roasted aroma, Tieguanyin has a prominent floral aroma

Black Tea: Rich and mellow, Dianhong has a citrus-like fruity aroma

Dark Tea: Ripe Pu'er is rich and mellow with an aged aroma; high-quality tea has a milky and smooth taste