TEA PROCESSING PROCESS FLOW

DIGRAMS RAJAT KATIYAR

General tea manufacturing steps

GREEN TEA PROCESSING PROCESS FLOW DIGRAMS

General processing steps in green tea

Cultivation & harvestingSteaming & fixingPre-dryingRolling & shapingFinal drying(roasting etc.) Grading, Sorting & Storage

PROCESS FLOW DIGRAMS FOR DIFFERENT METHODS OF

GREEN TEA PROCESSING

Tea Research Institute of Sri Lanka, Talawakele, Sri Lanka:

1.• Plucking • It is the process of harvesting of tea leaves.

2.

• Panning• This operation is accomplished in the 'Chekiang Green Tea Model 180' de-

enzyming machine. Furnace temperatures ranging from 250 to 550°C, exhaust temperatures from 45 to 65°C, feed rates from 5 to 15 kg min'1as well as single and double passes.

3.

• Cooling • Panned leaf was cooled immediately in a stream of cold air.

This was done by manually spreading the panned leaf in front of a 40 cm (16") X-pel air fan mounted on a 0.6m (2 ft) stand.

Tea Research Institute of Sri Lanka, Talawakele, Sri Lanka …continued

4.• Roll breaking • Roll-breaking was carried out on- a standard 1.3m (4.5 ft)

rotary roll-breaker fitted with a No. 4 Gl mesh.

5.• Drying • In drying the moisture of the tea leaves is brought down up-

to 3-5% by using Walker's pressure driers 'Standard' model MK 1.

6.

• Shifting & sorting • The sifting machines used were Myddleton stalk extractor,

Michie sifter, Japanese tea cutter and suction winnower. The perforations of the two bubble trays of the Myddleton stalk extractor was top tray 0.47 cm (3/16") and bottom 0.6 cm (1/4").

Processing of “Sencha” green tea:

1.

• Steaming & cooling• When the fermentation stops, the steamed leaves

take on a fresh green color. The leaves now contain about 75 % water.

2.

• Rolling• Rolling is carried out several times in Primary drying

tea roller, Tea roller, Secondary drying tea roller, Final drying tea roller.

3.

• Drying• This machine consists of an air heating

furnace, a drying chamber, and net conveyors. The aim of this step is to uniformly reduce the water content in the leaves from about 13 % to 6 % while maintaining the quality and fragrance.

Processing of “Sencha” green tea:

4.

• Final roasting • After storage, the aracha is loaded into a microwave oven

for roasting. When the water has evaporated from the leaves, their temperature starts to rise. When this temperature reaches a temperature in the vicinity of 150° to 170° C., the process is complete, or very nearly complete.

NOTE

• ARACHA• It is the same tea that is processed by same above

procedure upto step 3.

NOTE

• Aracha tea is also known as “crude tea”.

Standard in making process of crude tea(Sencha)

S.no.

Machine Revolution RPM

Air temp. Time required

Less weight

Water content

1 Tea steaming machine 35-50 Steam 30-60 sec.

0% 75%

2 Primary drying tea roller

36-38 90-110 30-45 min.

55-60% 50%

3 Tea roller 22-28 Non heating 15 min. 0% 50%

4 Secondary drying tea roller

26-28 50-60 30-40 min.

58-70% 30%

5 Final drying tea roller 50-60 (cpm) 80-90(pan temp.)

30-40 min.

73-75% 13%

6 Tea dryer ______ 70-90 25-30min.

77% 6%

Green tea processing in Varie Tea, Tea Garden, Assam

1.• Plucking • Harvesting of green tea leaves

2.• Storage • Storing of tea leaves in a controlled atmosphere

3.• Withering • It is done under controlled atmosphere.

4.• Cutting • Providing the tea leaves of a particular shape.

5.• Drying • To bring down moisture content in the tea leaves up to 3-4%.

Another method for processing green tea

1.• Plucking of green tea leaves• Harvesting process of green tea leaves.

2.

• Fermentation stopping• Either by steam or hot water. To achieve this with a drying drum, the

temperature inside the drying drum should be kept at about 250 - 300°C. Or, if you are using boiling water to steam the tea, then the metal basket containing the fresh leaves should be dipped in the boiling water for 20-60 seconds.

3.• Rolling • It is done in rolling machine and tea leaves are rolled to provide

shape to the tea leaves.

4.• High temperature drying• The rolled tea is placed in the drying drum with a hot fire kept at a temperature of

about 95 - 100°C.

Another method for processing green tea………..continued

5.

• Low temperature drying • Once the tea has reached about 40 - 45% water content, reduce the

heat of the fire. Continue turning the drum slowly but not too slowly. Try to hold the tea at a temperature of 70 - 75°C.Continue drying the tea at this temperature until the tea reaches a water content of only 4 -5%. As a rough estimate, this will take about 30 minutes.

6.

• Classification • To separate the higher-grade tea from the lower-grade tea. • One of the criteria used to judge tea quality is the grade (in

other words, the physical size and form of the pieces of tea).• To ensure that all the tea in a specific grade has a similar size.

7.

• Final roasting • "Roast" the tea at a relatively high temperature for a few

minutes, turning the drum slowly. But, do not allow the tea to scorch.

• This final roasting gives the tea a good flavour.

Green Tea Processing TechniqueIng. Agr. Patricia A. Parra ,Buenos Aires,Argentina July 2014

1.• Plucking • Young and tender material is collected for a high quality Green Tea. The raw material

should be tender, even and fresh.

2.• Fixation• first step in Green Tea primary processing, critical to obtain high

quality. It aims to destroy the enzyme activity of fresh tea leaves with high temperature

3.• Rolling• The tea leave quantity, time and pressure, are major technical factors

during rolling.

4.•Drying•Necessary to achieve a high quality Green Tea. Shape is defined and fragrance finishes its development. This process needs several stages, such as: 2nd drying, 3rd drying and final drying.

Processing Technology of Green Tea1. • Plucking or harvesting of green tea leaves2. • Withering 3. • Pan frying or steaming (up to 2 minutes)4. • Initial rolling (10 minute)

5. • Final drying (30 minutes)6. • Final rolling (15 minutes)7.

8. •Green tea

• Shaping

MANUFACTURING PROCESS OF GREEN TEA LEAVES WITH FRYER

1.• Plucking • Harvesting of green tea leaves.

2.• Roasting • Roasting was done by fryer (250 ̊̊̊ᴄ & 25 minutes).

3.• 1st Rolling • Using rolling machine rolling was done.

4.• 1st Drying• Drying was done by fryer(180 ̊̊̊ᴄ & 15 minutes).

5.• 2nd Rolling • After 1st drying 2nd rolling was done for providing final shape & size to the tea

leaves.

6.• 2nd Drying• Final drying was done by fryer(100°C, 40 minutes).

MANUFACTURING PROCESS OF GREEN TEA LEAVES WITH FRYER & FIR

1.• Plucking • Harvesting of the green tea leaves.

2.• Roasting • Roasting was carried out with Fryer & FIR(250°C, 15 min & 300°C, 5 min)

3.• Rolling • Using rolling machine rolling was done.

4.• Drying by fryer• Drying was carried out by using fryer(180°C, 15 min).

5.• Rolling • After drying by fryer 2nd rolling was done for providing final shape & size to the tea

leaves.

6.• Drying by fryer • Drying was carried out by using a fryer(100°C, 40 min).

7.• Drying by FIR• Drying was carried out by using a FIR(300°C, 15min).