Methods of manufacturing and fermentation of tea

1. Methods of Manufacturing and
Fermentation of Tea
A presentation by -
Mahmudul Hasan
Registration no : 2011337061
Shahjalal University of Science & Technology
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2. Manufacturing Methods of Tea
There are mainly two methods
1. Orthodox Method
2. Unorthodox Method
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3. Orthodox Manufacturing of Tea
• Traditional method of tea manufacturing
• Preserves the integrity and flavor of the leaf
• Whole tea leaves are rolled into various sizes and styles
• It is an artisan method
• Takes longer to produce but produces an attractive full leaf tea with
complex flavor and aroma
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4. Orthodox Manufacture
• Orthodox Machine consists of a vertical metal cylinder hopper having opening
at both ends
• The weight is placed on the upper end of the cylinder to compress the leaf
• The cylinders are then rotate centrifugally over the surface to the table for 20-
30 min to be rolled bruised and broken up into fragments
• Pressure and rotation should be adjusted
Figure 1:Orthodox manufacturing
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5. Unorthodox Manufacturing of Tea
• Also known as CTC ( Crush, Tear and Curl ) manufacturing of Tea
• Yields small, intentionally shredded pieces of tea
• Originally designed for Commercial Tea Bags
• This is mainly a machine-driven production method
• Can only produce a one dimensional flavored tea (lacks the ability to
produce a wide range of teas and tea flavors )
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6. Withering
Rolling
Fermentation
Sorting and
Grading
Drying
Withering
CTC
Fermentation
Sorting and
Grading
Drying
Orthodox Manufacture Unorthodox Manufacture
Figure 2: Flowchart of orthodox and unorthodox manufacture
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7. Figure 3:Unorthodox manufacture
Figure 4: Unorthodox Tea4/24/2019 7

8. What is Fermentation ?
 It is actually an oxidation process in a controlled atmosphere
 In chemically, fermentation is the conversion of colorless catechins to a
complex mixture of yellow-orange to red-brown substances
 Polyphenol broken into theaflavin and thearubigin
 Theaflavin – Briskness & Brightness
 Thearubigin – color & strength
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9.  General fermentation generally involves microbes
 Tea fermentation is basically an oxidation process, does not involve microbes
A flow diagram depicting the steps of oxidation involving the fermentation
tea is given below:
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10. Biochemical Changes During Fermentation
• Mainly two types of changes occur
i. Enzymatic
• Formation of theaflavin and thearubigin
• Breakdown of chlorophyll
• Changes in carotenoids , organic acid and neucleotides
ii. Non enzymatic
• Interactions of oxidized polyphenols and sugar with amino acids
• Tanning of enzymes and other proteins
• Reduction of number of microorganisms
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11. Classification of Tea based on Fermentation
 Fermented tea: e.g. Black tea
 Semi-fermented tea: e.g. Oolong tea
 Unfermented tea: e.g. Green tea
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12. Methods of Fermentation
• Conventional:
i. Floor fermentation (better air contact)
ii. Sheet metal rack and glazed tiles (ensures cleanliness)
• Modern Methods:
i. Trolley fermentation (economical)
ii. Drum fermentation (gives tea better appearance)
iii. Continuous Fermenting Machine (CFM)
(eradicates microorganisms)
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13. Hygiene Control
• Cleaning of Fermenting room daily
• Roller should be frequently cleaned
• Fermenting room should be more ventilated
• Humidified air flow should be maintained
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14. Fermenting Techniques
 Tea manufacture is essentially an oxidation process
 For better fermentation , the air should be fresh, cool and saturated with
moisture
 The temperature of fermenting drum should be maintained between 25 to
27 degree centigrade with 95 percent relative humidity
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15. Factors Influencing Oxidation
Duration : 60-90 minutes (South India)
Temperature : 27 ℃
Humidity : around 95%
Aeration : optimum
Thickness of Spreading : Floor Fermentation
Cleanliness : Hot water sterilization
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16. References
• http://www.tocklai.net/activities/tea-manufacture/factory-hygiene/
• https://en.wikipedia.org/wiki/Crush,_tear,_curl
• http://www.upasitearesearch.org/orthodox/
• http://www.upasitearesearch.org/ctc/
• https://www.teatulia.com/tea-101/tea-processing.htm
• Tea Science by D.L. Sana
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17. Thank you
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