Harvest / Processing

Producing Black Tea

 

The gren tea leaves are mainly plucked by women, thanks to their delicate hands, who are wearing a basket or linen over their shoulder in which they are collecting the leaves. The rule „two leaves and the bud“ is strictly followed. The plucked leaves are examined on the collection point and weighed before the actual processing starts which is divided into five separate processes:

 

1) Withering

Here, the thick and still immalleable leaf is rid of approximately 30% of its humidity. There are two methods:

a) The natural withering where the leaves are spread out on laths which are covered with jute, wire or nylon nets. The withering time takes, depeding on the weather and humidity content of the leaves, between 14-18 hours.

b) The modern withering in large troughs of a length of 25-30 metres which are covered with wire grids and are ventilated with large ventilators. These can also be used to warm the leaves, should it be necessary, to reduce the withering time to 8-12 hours.

2) Rolling     

 

Orthodox Method

With the help of press spindles or rollers where the still green leaves are cut open and the released cell fluid reacts with the oxygen in the air (= oxidation similar to that of a bitten into apple). This process takes 30 minutes each and is repeated 3 times. The damp and lumpy, now dark green leaves are scattered with the help of a shaking or sieving machine.

CTC - Method (= Crushing – Tearing – Curling)

Once rolled for 30 minutes, the entire leaves are torn in specially constructed thorn drums. The stems and leaf ribs are separated as far as possible and only the torn "meat" of the leaves is processed further. This simple processing gives much higher yields compared to the classical production method. Due to the large internal demand, this method is used in India in 50% of the entire processing today.

3) Fermentation

This oxidation and fermentation process already starts with the rolling. The leaves are spread out on large boards in 10-15 cm thick layers in a special room with a room temperature of 40°C for 2/3 hours and additionally sprenkled with water. Thereby, the leaf takes up its copper-red to brown colour and starts to unfold its unique aroma which can be found again, when the tea is infused. The correct fermentation is very important for the final quality of the tea.

4) Drying

On the high point of the fermentation, the leaves are transported through so-called tiered dryers on metal conveyor belts. The tea is dried for approximately 20 minutes with hot air of 80-90°C which makes the cell fluid stick to the leaves and gives it its dark brown to black colour. The final humidity of the leaves is betwenn 5-6%.

5) Sieving/Sorting

The finished tea is then sorted into common grades via mechanical jarring sieves. A good, high-yielding production has the following results / qualities:

d

 

Leaf (SFTGFOP1, FTGFOP1, TGFOP1, GFOP, FOP) = 6%

small leaf (FP, PEKOE) = 20%

large Broken (FBOP) = 15%

feine Broken (GFBOP, GBOP) = 20%

Fannings (BOPF, OF) + Dust (PD);

both grades are for tea bags only = 39%

Explanation of the abbreviations with the use of some examples:

S (=Super) F (=Finest) T (=Tippy) G (= Golden) F (= Flowery) O (=Orange) P (=Pekoe) F (=Flowery) P (=Pekoe)G (=Golden) F (=Flowery) B (=Broken) O (=Orange) P (=Pekoe).BO (=Orange) P (=Pekoe) F (=Fannings) (=Broken)

Further quality descriptions, like above, are formed out of these abbreviations. Black tea usually has a dark-brown until black leaf and can taste anything from fine-flowery to fully aromatic and strong.

The green tea production is differentiated into two methods, the Chinese and the Japanese method.

Production Green Tea => China

1) Plucking  

The gren tea leaves are mainly plucked by women, thanks to their delicate hands, who are wearing a basket or linen over their shoulder in which they are collecting the leaves. The rule „two leaves and the bud“ is strictly followed. The plucked leaves are examined on the collection point and weighed before they are transported to the tea factory. Here, the supplied amounts are weighed again and registered before the actual tea production is started.

2) Withering  

Good qualties are spread out on laths which are covered with jute, wire or nylon nets and placed out in the sun to wither. The withering time takes, depending on the weather and humidity content of the leaf, between 14-18 hours. Normal qualities are spread on large sieves for the withering process. Huge ventilators blow air from below through the leaf layers. 30% of the still thick, immalleable leaf's humidity is reduced during the withering process.

3) Heating

Now, the leaves are heated for 10 minutes with 280°C in wok-like, cast-iron pans. The leaves are pressed against the hot surface and turned. Sometimes, also larger, automatic drums are used in this process.
Due to the impact of the heat, the plant's own enzymes are converted. An oxidation can no longer take place and, hence, the green colour and the rather fresh or herb taste are preserved.

4) Rolling 

In a so-calle rolling machine, the tea leaves are put in betwee two rotating metal plates. This process takes approximately 15 minutes.  

5) Drying 

Subsequently, the leaves are put into special dryers. Here, there are two turning discs which are heated to 160°C.

Production Green Tea => Japan  

Nowadays, the process of green tea distribution in Japan is almost entirely automated. The process is somewhat more complicated than that of the Chinese. It comprises the following steps:

 1) Withering 

The withering reduces approximately 30% of the humidity content of the leaf within a time of 4-12 hours.

2) Steaming 

The leaves are now moved through a turning drum. Hot steam is added. After about 2 minutes, the leaves are extracted again. The amount of steam is the deciding factor in this step. Too much spoils the leaves and too little initiates the onset of the fermentation.

3) Drying 

In a wooden drum, the leaves are now swivelled around for approximately 30 minutes in 55°C warm air. Large forks are turning inside the drum in order to prevent the lumping of the leaves. During this process, the leaves lose about 50% of their rest humidity content.

4) Rolling  

Now, the leaves are rolled in a rolling machine for about 10 minutes with differing pressure.

5) Drying 

A further drying sequence follows. The leaves are brought into contact with hot air for approximately 30 minutes in order to dry them further.

6) Polishing 

In some factories, the leaves are now polished. This is done via pressing the leaves against a hot plate. This makes the leaves very flat and glowing. However, this step is not vital.

7) Drying 

The leaves are now dried a final time for about 20-30 minutes with a temperature of 60°C. The finished green tea contains a rest humidity of ca. 3-4%.