Day one (25th August 2017)  Introduction  Tea manufacturing a) Withering b) Rolling c) Fermentation d) Drying e) Sorting and Grading  Tea testing  Important characteristics of tea leaf & plant  Tea Seed Bari( Guti Bari)  Day two (26th August 2017)  Revisit of the manufacturing process  Tea machinery room  Mother bush visit  Nursery visit a) Sapling b) Seedling  Ball measuring method

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Acknowledgement
A tour has been conducted under the course no. FET 329 and course title. Industrial Training 1
with our honorable two teachers Professor Dr. Iftekhar Ahmad and Md Yasin Anwar in
Lackatoorah Tea estate of National Tea Company Ltd in sylhet, Bangladesh on 25th
and 26th
August, 2017. It was a two days long tour and was conducted with great compassionate and
participation from both students and teachers. We were acquainted with the tea processing system,
tea testing, important factors regarding the tea business and industries and challenges for good
quality tea manufacturing. We are grateful to our teachers and Lackatoorah Tea estate Assistant
manager for giving us the opportunity of a very informative and important practical knowledge
based tour in tea estate.

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Contents
 Day one (25th August 2017)
 Introduction
 Tea manufacturing
a) Withering
b) Rolling
c) Fermentation
d) Drying
e) Sorting and Grading
 Tea testing
 Important characteristics of tea leaf & plant
 Tea Seed Bari( Guti Bari)
 Day two (26th August 2017)
 Revisit of the manufacturing process
 Tea machinery room
 Mother bush visit
 Nursery visit
a) Sapling
b) Seedling
 Ball measuring method

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Introduction of Lackatoorah Tea Estate:-
Lackatoorah Tea estate as a part of National Tea Company Ltd. has been
formed in the year 1978 under the Companies Act, 1913, as a Public Limited Company. It is a
Joint venture of the Government and the General Public. Thus it occupies a unique position of
being the first in the field of joint ownership of Public and Private interest in Tea sector.
(Government and its financial organization holds 51% of shares and rest 49% by the General
Public) The National Tea Company Ltd. Started with 9(nine) “A”-class tea estates all of which
are situated in the Sylhet division. The tea estates are: Patrakhola, Kurmah, Champarai,
Madanmohanpur, Madabpur, Jagadishpur, Teliapara, Chundeecherra and Lackatoorah.
Tea Processing System:-
Withering
Withering refers to the wilting of fresh green tea leaves. The purpose of withering is to reduce the
moisture content in the leaves and to allow the flavor compounds to develop. While it can be done
outdoors, controlled withering usually takes places indoors. Freshly plucked leaves are laid out in
a series of troughs and subjected to hot air forced from underneath the troughs. During the course
of withering, the moisture content in the leaf goes down by about 30%, making the leaf look limp
and soft enough for rolling. Additionally, the volatile compounds in the leaf, including the level
of caffeine and the flavors, begin to intensify.
Withering trough:
WITHERING TROUGHS are generally installed in the first floor of the factory. Green leaf is
spread over a wire mesh which is fitted on plenum chamber. Height of the plenum chamber is 0.6-
.76 m (2-2.5 feet) and leaf is loaded over the mesh to.20-.23 m (8-9″) height or 8-9 kg/sq. m. (2.5-
3 kg/sq. ft.) of the withering trough. Size of the withering trough is 70-100′ long 1.8 m (6′) wider
or 22.9 m (75′) long and 1.8 m (6′) wide. Better withering can be achieved with smaller trough
22.9 X 1.8 m (75′ x 6′). In general the motor RPM is 750 and fan size is 40 inch number of rotor
is 6-8. The trough should be fitted with a suitable fan to deliver the required quantity of air as per
the size of the trough. To achieve proper withering the fan has to deliver 45 CFM air for every one
square foot of trough area. For artificial withering hot air from the drier room is bulked with outside
air and used. Fans are arranged in such a way that they can draw hot air from the drier and cool air
from the atmosphere.
Withering times:
The withering time greatly depends on weather condition, relative humidity and many other
factors. Generally it takes 8-12 hours. In winter withering starts within 1/1.5 days but sometimes
it takes 4-5 days for weathering when the relative humidity is too high.

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Rolling
Now the leaves are ready to be rolled using rolling machines. This process breaks the leaves into
pieces, thereby crushing the leaf cells. This releases the natural chemical compounds and natural
fluids that promote fermentation. The rolling process is repeated a few times more so as to break
the leaves into still smaller pieces in CTC (Crush Tear Curl) Machine system. The CTC Machine
system consists of a pair horizontally mounted opposite spin stainless steel roller. Though the
machine named as CTC (Crush Tear Curl) according to its functional operations , it can be called
as TCC (Tear Crush Curl) according to its sequential functional operations. Withered leaf comes
in contact with slow rotating roller at 70 rpm with a counter rotating roller at a 700 rpm and being
crushed. There are five cutting steps to attain more even size and pattern grades. Then tea shifted
into googy shifter. It is a long big drum and it can rotate horizontally. In side, this drum is smooth
and the dhool is placed in the side it with continuous rotation.

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Fermentation
Oxidation results in the browning of the leaves and intensification of their flavor compounds. From
the moment they are plucked, the cells within the tea leaves are exposed to oxygen and the volatile
compounds within them begin to undergo chemical reactions. It is at this stage that polyphenolic
oxidase, including theaflavin and thearubigin, begin to develop within the leaves. Theaflavin tends
to briskness and brightness to the tea while thearubigin offers depth, color and fullness to the liquor
that’s produced. In order to bring out specific intensities in flavors, tea makers control the amount
of oxidation the leaves undergo. Controlled-oxidation is typically carried out in a large room where
the temperature is maintained at 25-26 °C and humidity stands steady at 100%. Here, withered and
rolled leaves are spread out on long shelves and left to ferment for a fixed period of time, depending
on the type of tea being made. To halt or slow down oxidation, fermented leaves are moved to a
panning trough where they are heated and then dried. Due to oxidation, the leaves undergo a
complete transformation and exhibit an aroma and taste profile that’s completely different from
the profile of the leaves that do not undergo this process. Less oxidized teas tend to retain most of
their green color and vegetal characteristics due to a lower production of polyphenols. A semi-
oxidized leaf has a brown appearance and produces yellow-amber liquor. In a fully oxidized tea,
amino acids and lipids break down completely, turning the leaves blackish-brown. The flavors in
such a tea are more brisk and imposing. The fermentation process takes 1 hour 20 minutes to
complete.

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Drying
Drying enhances a tea’s flavors and ensures its long shelf-life. Also, drying brings down the tea’s
moisture content to maximum 3%. To dry the leaves, they are fired or roasted at a low temperature
for a controlled period of time, typically inside an industrial scale oven. If the leaves are dried too
quickly, the tea can turn abrasive and taste harsh. Vibrio Fluid Bed Dryer used in this factory.
Optimum ranges of inlet and outlet temperature are 135 °C -140 °C and 80 °C -85 °C

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Sorting and Grading
A number of hand sievings are also essential to produce some quality grades. In wind tunnels, fibre
and dust grades are separated according to the specific gravity of the particle. Tea breakers and
cutters are extensively used in modern sorting operations to reduce particle sizes for subsequent
classification.
In orthodox manufacture, the first classification of tea takes place at the time of sifting. BOP,
FBOP and OF grades are produced from the first and second fine teas. The coarse leaf that is first
broken or cut goes into the production of PF grade. In CTC and leg cut manufacture, sorting is
based wholly on the size of the leaf particles. Besides Flowery Orange Pekoe (FOP) , Dust quality
are also classified into 3 sub grades namely Dust ,Red Dust , Churamoni Dust. Large granules
from grader are returned to rotor vane for further processing.

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HOW TO TASTE TEA
When we're tasting tea we look for four key features: appearance, aroma, flavor and mouth feel.
We will learn about all of these on this tea tasting journey… Interestingly, their roots lie in the
Chinese tea ceremony. Understanding the full picture of what is happening around you is one of
their key teachings.
1. FIRST IMPRESSIONS COUNT
As a tea taster, the first thing you do is inspect the dry tea. Surprisingly, a large proportion of our
overall option is based on its look:
SHAPE - what are the bits of tea like? Small? Large?
COLOUR - is it all the same color? Is it jet black? If it's all different colors then it might be a
blend
TEXTURE - is it finely ground like dust? Is it crumbly? Sticky?
TEA BUDS - can you see any?
SIGNS OF A GOOD LOOSE TEA:
 In Black, White and Green tea: Gold or Bronze flecks - these are the young leaves called
tippy
 It should crunch between your fingers - this means it hasn't absorbed any moisture (or
flavor) from the air around it

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 Buds
2. MAKING THE PERFECT BREW
We've already started to talk about set standards - tea tasters talk about them a lot. They're
necessary to make sure that every tasting is consistent. So we'll always use the same.
Standard Approach by Tea Tasters - this is somebody who tastes tea the same way.
Weight of tea – Take 1 gm tea
Water – Take 100 mL water
Crockery - Every tea taster in the world will use the same crockery - but you can just find the
purest, whitest crockery you can get your hands on. This will help you to see the colors and
depths.
Brew time - that's five minutes. It's the right amount of time for the color, flavor and goodness to
come out. It’s best not to overly squeeze your tea bag because this could release deep rooted
tannins and they taste very bitter.
3. NOW WHAT DOES THE INFUSED TEA LOOK LIKE
In the world of tea, we call the infusion 'liquor'. When we're inspecting the liquor, we look for.....
Color - does it leap out at you? We are looking for a bright, jewel-like color.
Physical Appearance - we are looking for shiny, slightly oily and bright? It's fine to have alittle
fragments floating around the bottom of the cup.

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4. HOW DO WE TASTE? HERE'S THE SCIENCE BIT
When we think of taste, we think of our tongue. Some studies have suggested that up to 90% of
flavor is perceived through smell. Our tongues detect five essential tastes and these give us our
initial impression.
When we think of taste, we think of our tongue. But in fact up to 90% of flavor is perceived through
smell. Our tongues detect five essential tastes and these give us our initial impression
sweet, salty, acidic, bitter, umami (a word from Japanese, meaning 'pleasant savory taste'). The
initial perception of something can sometimes throw you off the taste, so that's why it's important
to first take in the aroma. Our taste buds form part of an intricate system that allows our brain to
decide on a taste. The taste buds along with gustatory receptors and the Olfactory gland allow our
brain to make a quick decision on whether or not we recognize and like the flavor of what we are
about to ingest.
5. AROMA - LET'S TAKE A LITTLE SNIFF
Because we mainly taste through our sense of smell, it's important to deeply consider the aroma.
There are two techniques for sniffing, these are:
Deep inhalations - this is when we hold the brew as close to your nose as possible and take a deep
breath.
Dog action - this is when we take rapid, shallow inhalations through the nose, rather like a panting
dog.
6. HOW TO TASTE AND SLURP
Here's the fun bit. It's when we actually get to taste the tea. So throwing all table manners out of
the window - here's what we do: Scoop up some of the liquor with spoon.
Take deep breath (first). Pucker up like we're about to give someone a kiss, then slurp the liquid
up into your mouth from the surface of the spoon. The louder the slurp, the better. You do this to
mix oxygen with the liquor as it helps to bring the flavors to life. Now we need to breathe out
through your nose (whilst keeping your mouth closed) - this is called retro-olfaction
perception. Then swallow the liquor. Pay special attention to any sensations created on the tongue
for example sweetness or savory. And remember that bitterness is present in the majority of teas
because of varying degrees of tannins.
7. WHAT'S THE FLAVOUR LIKE
When we're tasting not all aromas and flavors are detectable at the same time. There can be many
complex layers of taste for us we will just look for three different notes: head, body and tail. You
can use our flavor wheel for this part. Head notes (First impressions) are the ones that give you the
initial impression, and they come thick and fast.
Thinking about this first impression look at the inner ring of your taste wheel and describe what
you feel you taste, different people may find different tastes, after a few years of tasting in this
way you will find that you start to taste in a standard way, as we discussed before.

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8. HOW DOES IT FEEL
It's funny to talk about mouth feel, but it's important as it indicates strength. Again, we can use the
taste wheel for this but it's often better to use what feels right. Mouth feel is all about the sensations
you feel in your mouth when you taste tea. And of course, different teas trigger different sensations.
Some are smooth and round, some are drying. Often this is the connection between taste and smell
- it's what makes us want to taste the tea again.
Important characteristics of tea leaf & plant
Boat leaf – From the pruning scar third leaf is known as boat leaf. This leaf shape seems to be
boat like that’s why it is known as boat leaf.
Fish leaf – From the pruning scar second leaf is known as fish leaf.
Janam leaf – The small leaf present in the pruning scar is known as janam leaf.
Tea seed Bari
Tea seeds are produced in seed baries (orchards) planted especially for the purpose where the
parents (selected generative clones) of approved stocks are established either planting directly or
by grafting on any vigorous jat/clonal root stocks. Tea seeds are produced over the entire surface
of a seed tree. Therefore, the planting distance between seed trees should be such that at maturity,
the lower branches at the point of maximum spread of two neighboring trees do not overlap. In
general, spreading type of plants require about 5.5-6m space between them, while the erect type
and Chinery plants may be planted at a closer spacing of 3.5-4.5m and 3-3.5m. The planting of
seed bearers may be either square or triangular design. The number of plants varies from 330 to
1283/ha, depending on spacing and design of planting used. When the both parents are seed
bearers, they are planted alternately in each row. If only one of the parents is a seed bearer, then
the planting pattern is such that the male parent (pollen donor) is surrounded by a few seed bearers
(female). Seed baries can be raised on any soil suitable for tea cultivation. A well-drained, fertile
sandy loam to loam soil is most ideal.
Tea is a cross pollinated plant. Pollination is caused by pserphid, a small insect having a short
flying range. It is therefore, necessary to isolate seed baries from other teas to avoid undesirable
out crossing. A minimum distance of 10m should separate the seed baries from main tea fields
during
Planting, after planting care and manuring are similar as that of young teas. Mature trees should
be manured with NPK 2:1:2 mixture @ 100 kg N/ha/year in spring. Pruning is not recommended

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except to remove unwanted shoots to clear congestion which will facilitate aeration and light
penetration. For higher seed production, 30-40% sunlight should reach the ground in a diffused
manner. If there were large height difference between the clonal pairs (parents), balancing the
height by lopping would facilitate efficient pollination. Old seed baries can be rejuvenated by
heavy pruning (MP) as in tea under plucking. The major part of flower bud initiation (75%) takes
place during March-June and about 97% of the flower bud formation is completed by end-
September. Blossoming generally starts from early-October and ends by January with a peak
period in November-December. Most of the seeds are produced from this peak flowering after 10
months. The seeds ripen by next October. The November-May period is very crucial for fruit
development and moisture deficit in this period affects the seed yield adversely. The tea fruit is
allowed to dehisce on the tree and the dropped seeds are collected from the ground. As these seeds
lose viability rapidly, the normal practice is to collect them every day. Tea seeds vary in size from
10 to 22 mm dia.
Tea machinery room
On the second day, we went to the workshop of the factory. Here we saw different types of machine
tools and machines. Among this the lathe machine is one of the most important machine in the
workshop.
The lathe is a machine tool which holds the work piece between two rigid and strong supports
called centers or in a chuck or face plate which revolves. The cutting tool is rigidly held and
supported in a tool post which is fed against the revolving work. The normal cutting operations
are performed with the cutting tool fed either parallel or at right angles to the axis of the work. .It
is also called as mother of machine. There are different methods of application of lathe machine
although turning method is the most suitable for the workshop in the tea processing factory.
Turning is the removal of metal from the outer diameter of a rotating cylindrical work piece.
Turning is used to reduce the diameter of the work piece, usually to a specified dimension, and to
produce a smooth finish on the metal. Often the work piece will be turned so that adjacent sections
have different diameters.
The sending speed of the tool also affects to the processing speed and the roughness of surface.
When the sending speed is high, the processing speed becomes quick. When the sending speed is
low, the surface is finished beautiful. There are 'manual sending' which turns and operates a handle,
and 'automatic sending' which advances a byte automatically. A beginner must use the manual
sending. Because serious accidents may be caused, such as touching the rotating chuck around the
byte in automatic sending.

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It expresses with the number of rotations (rpm) of the chuck of a lathe. When the rotating speed is
high, processing speed becomes quick, and a processing surface is finely finished. However, since
a little operation mistakes may lead to the serious accident, it is better to set low rotating speed at
the first stage.
The work piece had been set on the cutting tool. There were five cutters in the lathe machine. The
first three cutters were in 65degree angle and the last two were in 70degree angle with the work
pieces. Each portion of the teeth of the work piece takes 5 minutes. Although the total time needed
for the work piece to be turned is around 6 to 8 hours. The cutting tool should be changed after 70
hours interval. It is essential to keep the sharpness of cutting tool.
Nursery visit
V.P. Nursery - The purpose of vegetative propagation is to strike the nodal leaf-cuttings from the
desired tea plant and put in a suitable rooting medium for raising individual plants having similar
genetic constitution of the parents. For a successful nursery management through vegetative
propagation, it is essential to maintain ready stock of mother tea bushes from which the nodal
cuttings are supplied to the V.P. nursery. The mother tea bushes are selected from the existing tea
plantation. Here in Lackatoora tea estate for cutting BT6 mother bush is used and slightly brown
part of the shoot is taken, green shoot is ignored. Also avoid the woody and the very succulent
parts of the branch.

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V.P. Nursery bed - Beds under low shade should be north south oriented. Shade is provided with
the help of bamboo lath frame over the propagation beds, supported by sidewalls. The bamboo
lath frame should be raised gradually with increase in height of the plants. It is necessary to prepare
the beds at least 6-8 weeks before planting cuttings.
Plantation of cuttings - Using a sharp blade, make one-node cuttings taking care not to damage
the bud. The cuttings should be put in water before putting them in bed. Plant the cuttings in the
soil ensuring that the leaf does not touch the soil avoiding touching the woods. Water the cuttings
thoroughly but gently. Cuttings should be placed north-south direction. If the leaf of the cuttings
is large then cut the leaf at the point in which it bends. This cut off the leaf is done to avoid the
attack of the microorganisms in the leaf, maintain the respiration rate. For callusing takes 7-10
days and root growth within 15-20 days. After the height of the cuttings become 22-24cm then
through hardening they are transferred to the main field.
Seed nursery:
Tea seeds are collected from either general seed bari or bi /poly clonal seed bari. To obtained viable
seeds, the collection of seeds that lay on the ground beneath the seed bearers is made daily or
alternate day. After collection, seeds are preliminary sorted out according to the sizes, viz. small,
medium or large, which may vary from Jat to Jat. Thereafter the seeds are passed through the sieve
having 9-11 mesh to categorize the seeds for germination test.

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Germination test:
All seeds that passed over the shifter are placed in a large receptacle full of water, about 15cm
deep above the level of seeds that sink for about 24-72 hours. The true sinkers and floaters are
separated. The true floaters are then spread on a large tarpaulin. The cracked or split seeds are
picked by hand and put immediately in the nursery bed. Seeds which are cheesy, starred or
damaged are discarded.
Seed Nursery bed:
The nursery site is selected near the plantation. The nursery beds are designed with proper drains,
paths and roads. Beds may be of any length but the width of them should not exceed 1.5m.
Generally, a bed 1.5mx30m in size. The seeds are put in triangular pattern, about 3cm beneath the
soil and covered with loose soil light mulch. Proper shading and watering is necessary for the
development and growth of seedlings. Beds may be constructed with or without shade.

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Ball measuring method (Determination of % good leaf)
Ball measuring method is the way of finding percentage of good leaf in a plucking round. In this
method first randomly selected plucked leaves are taken weight against 100 uniform balls. Then
from the leaves different category leaves namely banjhi leaf, prematured shoot, perfect shoot etc
are categorized and then again taken weight against the ball. The remaining balls on other side is
the percentage of good leaf among a plucking round.