What are the different varieties of tea plants?
There are three main varieties of tea present in the world, all belonging to the Camellia sinensis species:
1. Camellia sinensis var. sinensis (Chinese tea or small-leaved tea):
- Native to China
- Smaller leaves, darker green, and more delicate
- Typically grown at high elevations (1,000-2,500 meters) in cooler climates
- Produces teas with lighter, more delicate flavors (e.g., green tea, white tea)
2. Camellia sinensis var. assamica (Assam tea or large-leaved tea):
- Native to the Assam region in India
- Larger leaves, lighter green, and more robust
- Grown in lower-lying areas (100-500 meters) with warmer and more humid climates
- Produces teas with stronger, more full-bodied flavors (e.g., black tea, Assam tea)
3. Camellia sinensis var. cambriensis (Cambodian tea or Java tea):
- Native to Southeast Asia (Cambodia, Vietnam, and Indonesia)
- Intermediate leaf size and flavor profile between sinensis and assamica
- Grown in tropical and subtropical regions
- Produces teas with a balanced flavor profile (e.g., oolong tea, some black teas)
These three varieties are the foundation for countless tea cultivars, hybrids, and blends, each with unique flavor profiles and production methods.
What is the oxidation process for popular types of teas?
Black Tea
The process of oxidizing black tea involves several steps:
1. Withering: Freshly plucked tea leaves are spread out in a controlled environment to allow excess moisture to evaporate (usually 12-24 hours). This makes the leaves soft and pliable.
2. Rolling: The withered leaves are rolled to release the enzymes that cause oxidation. This can be done by hand or using machines.
3. Oxidation (Fermentation): The rolled leaves are left to oxidize for a period of time (usually 2-4 hours), allowing the enzymes to break down the complex compounds in the tea leaves. This is where the characteristic flavor and color of black tea develop.
4. Turning: The leaves are turned or stirred to ensure even oxidation.
5. Firing (Killing): The oxidation process is halted by heating the leaves in hot ovens (usually 100°C - 120°C) or with hot air. This deactivates the enzymes and fixes the flavor and color.
6. Sorting and Packaging: The oxidized tea leaves are sorted by size and quality, then packaged for distribution.
Factors that influence black tea oxidation:
- Temperature
- Humidity
- Time
- Tea cultivar
- Rolling technique
Proper control of these factors ensures the desired level of oxidation, resulting in the characteristic flavor and aroma of black tea.
Green Tea
Green tea oxidation is a minimal process, as green tea is intended to retain its natural antioxidants and fresh flavor. Here's an overview of the process:
1. Withering: Freshly plucked tea leaves are spread out to allow excess moisture to evaporate (usually 2-12 hours).
2. Heat Treatment (Killing): The withered leaves are immediately heated to stop oxidation. This can be done through:
- Steaming (Japanese-style): Steam is applied to the leaves to halt oxidation.
- Pan-frying (Chinese-style): Leaves are heated in a hot pan to stop oxidation.
- Oven heating: Leaves are heated in a hot oven to stop oxidation.
3. Rolling: The heated leaves are rolled to shape them and remove excess moisture.
4. Drying: The rolled leaves are dried to remove any remaining moisture.
5. Sorting and Packaging: The dried tea leaves are sorted by size and quality, then packaged for distribution.
The goal of minimal oxidation in green tea production is to:
- Preserve antioxidants (catechins)
- Retain fresh, grassy flavor
- Maintain light color
By heating the leaves soon after withering, oxidation is halted, resulting in a tea that is characteristic of green tea.
Oolong tea oxidation is a partial process, falling between black and green tea production. The level of oxidation can vary, but here's a general overview:
1. Withering: Freshly plucked tea leaves are spread out to allow excess moisture to evaporate (usually 2-12 hours).
2. Shaking (Rattling): The withered leaves are shaken or rattled to bruise the edges and release enzymes, starting oxidation.
3. Oxidation: The leaves are left to oxidize for a period of time, which can range from 10% to 70% oxidation. This is where oolong tea's unique flavor and aroma develop.
4. Firing (Killing): The oxidation process is halted by heating the leaves in hot ovens or with hot air, deactivating the enzymes.
5. Rolling: The oxidized leaves are rolled to shape them and remove excess moisture.
6. Drying: The rolled leaves are dried to remove any remaining moisture.
7. Sorting and Packaging: The dried tea leaves are sorted by size and quality, then packaged for distribution.
Oolong Tea
Oolong tea oxidation levels can vary, resulting in:
- Light oolong (10-30% oxidation): Floral, green tea-like flavor
- Medium oolong (30-50% oxidation): Complex, fruity flavor
- Dark oolong (50-70% oxidation): Rich, nutty flavor
The partial oxidation process gives oolong tea its distinct flavor profile, balancing floral, fruity, and honey notes.
The oxidation process for fermentation of Pu-erh raw (Sheng) and ripe (Shu) tea is unique and involves microbial fermentation, which is different from the oxidation process in black, green, or oolong tea production. Here's an overview:
Raw Pu-erh (Sheng)
1. Withering: Freshly plucked tea leaves are spread out to allow excess moisture to evaporate.
2. Rolling: The withered leaves are rolled to release enzymes and start oxidation.
3. Oxidation: The leaves are left to oxidize for a short period (usually 10-20%).
4. Fermentation: The oxidized leaves are piled and covered, allowing natural microbial fermentation to occur over time (months or years).
5. Aging: The fermented tea is left to age, which can take years or decades, developing its characteristic flavor and aroma.
Ripe Pu-erh (Shu)
1. Withering: Freshly plucked tea leaves are spread out to allow excess moisture to evaporate.
2. Rolling: The withered leaves are rolled to release enzymes and start oxidation.
3. Oxidation: The leaves are left to oxidize for a short period (usually 10-20%).
4. Wet Piling: The oxidized leaves are piled and sprayed with water, creating a controlled microbial fermentation environment.
5. Fermentation: The tea undergoes rapid fermentation (usually 1-3 months), developing its characteristic flavor and aroma.
6. Drying: The fermented tea is dried to remove excess moisture.
The microbial fermentation process in Pu-erh tea production involves the action of fungi, bacteria, and other microorganisms, which break down the tea's complex compounds and create new flavor and aroma profiles.
White Tea
White tea, including Silver Needle, undergoes minimal oxidation, similar to green tea. The process is designed to preserve the tea's natural antioxidants and delicate flavor. Here's an overview of the oxidation process for White tea:
1. Withering: Freshly plucked tea buds are spread out to allow excess moisture to evaporate (usually 2-24 hours).
2. Air-drying: The withered buds are dried using natural air circulation or low-temperature machines to prevent oxidation.
3. Minimal Oxidation: The tea buds are allowed to oxidize for a very short period (less than 5%), which is often considered "non-oxidized".
4. Firing (optional): Some White teas may undergo a light firing or heat treatment to stop any residual oxidation.
5. Sorting and Packaging: The dried tea buds are sorted by size and quality, then packaged for distribution.
The minimal oxidation process helps preserve the tea's:
- Delicate flavor
- Light color
- High antioxidant content
Silver Needle, a type of White tea, is made from the young tea buds, which are harvested before they fully open. The minimal oxidation process ensures that the tea retains its characteristic:
- Silvery-white color
- Delicate, floral flavor
- Light, refreshing aroma
Note that some White teas may undergo a slight oxidation due to factors like weather conditions or processing variations, but the goal is always to minimize oxidation to preserve the tea's natural characteristics.