This document discusses the two main methods of manufacturing tea - Orthodox and Unorthodox (CTC). The Orthodox method preserves the integrity of whole tea leaves through rolling, resulting in complex flavors. The Unorthodox/CTC method shreds leaves for tea bags. It also describes the fermentation process of tea as an oxidation rather than microbial process, changing catechins into flavors. Key steps are withering, rolling, oxidation/fermentation, sorting and drying. Factors like temperature, humidity and aeration influence fermentation quality.

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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