Tea Classification & Manufacture
Tea plucking styles:
Imperial plucking – bud and leaf (usually harvested once a year in spring)
Fine plucking – bud and two leaves (also very high quality)
Medium plucking – bud and three leaves
Coarse plucking – Bud and four leaves (for wulong teas)
It takes 5Kg of fresh leaves, about 12 000 shoots to produce 1kg of tea. In India a tea picker will harvest on average 30 – 50kg of leaves per day.
Hand plucking is the best for tea as it allows the pickers pluck the best shoots and it doesn't damage the bush.
Machine harvest usually pluck too many leaves and damage the bush, afterwards the leaves have to be sorted into desirable grades in factory (Japan).
Before Robert Fortune discovered the “secret” of tea in the mid 19th century, Europeans believed that green teas and black teas came from different plants. We know today that it is the phenomenon of oxidation that modifies the natural state of the leaves, changing the colour and taste.
We have 6 different categories according to manufacturing style of tea:
1) White tea – very light spontaneous natural oxidation
2) Green tea – no oxidation
3) Yellow tea – light fermentation
4) Wulong tea (Oolong tea) – partial oxidation (10-80%)
5) Black tea (called red tea in China) – full oxidation
6) Dark tea (Pu erh) – post-manufacture fermentation and oxidation
Tea manufacturing terminology:
Withering – to reduce the water in the leaf, prepare the leaf for rolling (Sun wither increases sugars in leaves)
Panning or Steaming – to kill the enzymes that allow oxidation to take place, Known as “kill green”, “de-enzyming” or “de-naturing”
Rolling/Cutting – to break down the cells of the leaf, to develop the flavour of the tea and prepare leaves for oxidation.
Oxidation – to develop stronger taste and aroma compounds, to give strength and briskness, leaf colour changes from green to brown
Fermentation (Smothering) – to develop taste and aroma compounds, to give strength and briskness, leaf colour changes to yellowish hue.
Drying/Firing – stop oxidation and reduces water content of the leaf to 2-3%
Sorting/ Grading – to separate into particles of roughly the same size, de-stalking
Oxidation in tea: It is a chemical reaction between the juices in the tea leaves and oxygen in the air.
As the leaves oxidise they will turn from green to brown as an apple if you cut it and leave it for a while. The oxidation process can be prevented by applying heat.
Fermentation/ Smothering: takes place in tea when bacteria are activated by the presence of water (steam or dampness). It happens when no or very little oxygen is present. Like in a wine making. The tea leaves are covered or wrapped with damp cloth for a period of 4 – 10hrs.
Detailed manufacture for the six classes:
At start - all teas are being picked (manually or mechanical plucking) and immediately taken to factories.
At the end - all teas are being sorted (manually or mechanically – through sieves) and packed.
White Tea: Sun Withering (12-24hrs), Drying
Green Tea: Short Wither (sometimes), Panning or Steaming, Rolling, Drying
Yellow Tea: Withering, Panning, Gentle hand roll (sometimes), Smothering, 2nd panning, 2nd smothering, Drying
Wulong (Bluegreen)Tea: Sun Withering, Indoor Withering (Shaking rattling, bruising to provoke 20-90% Oxidation, Panning, Rolling into shape, Drying
Black Tea: Withering, Rolling, Full Oxidation, Drying
Pu Erh Tea: Withering, Panning, Rolling, 2nd panning, 2nd rolling, Drying in the sun (in this stage the tea leaves are called MAOCHA)
- Sheng Pu Erh (raw): Maocha steamed, compression into cakes (or other shapes), stored in humidity and temperature controlled conditions....Shengs are ageing for years.
- Shou Pu Erh (ripe): Maocha sprayed with water, Smothering, after few weeks – compression, air drying, Shou can age up to 10 years only.
Closer look of Tea Manufacture for different countries:
Only China produces all six classes of teas for over 5000 years and its quality is spectacular. The long tradition of processing is an art, which the Chinese mastered many centuries ago. Every region has its own specific process, which has given rise to new types of teas. Most of the Chinese processing methods are still the small-scale traditional methods, hand made, passed from generation to generation. These methods are the best for developing high quality teas with distinctive characteristics from specific terroir. Quality over quantity!
Taiwan is knows for its fabulous Wulongs and they producing one of the bests. A Wulong tea can be closer to a green tea or a black tea depending on its degree of oxidation. Green ones are oxidised to 10-50% (vegetal, floral bouquet) and black ones from 50-70%. (sweet, woody notes)
Japan is known for its steamed green teas and Matcha which is used in Chanoyu Tea ceremony. For the production of green teas, the Japanese “fire” the leaf using steam, also known as the “Uji method”, this process preserves extremely fresh aromas with notes of the sea and herbaceous plants. Because of the high labour costs, Japanese growers turns the tea leaves into Aracha a raw product which is then sold at auction to companies who complete the processing (steaming, rolling, drying), therefore most of Japanese teas are a mix of many plantations.
India is famous for 1st flushes Darjeelings and Black rough heavy Assam teas - good for Indian Masala Chai or enjoyed with lemon or milk in other lands.
Sri Lanka is well known for its light honey Ceylon teas, pleasant and easy to drink. Ceylon teas never go cloudy, therefore great for cold brews.
Vietnam producing couple of green teas which are silvery green and easy to drink. Most famous would be Thai Nguyen from Northern Mountain area of Vietnam or Lotus leaf teas.
Africa As Africa is near equator, planted with var. assamica it is producing tea more with body than aroma, therefore suitable to blends or teabags.