Major Steps in processing of Tea plant

1. TEA PROCESSING
Presented by
Fatima Batool
Roll # 04

2. Tea processing -leaves from the tea plant
Camellia sinensis are transformed into
the dried leaves for brewing tea
starts with freshly-plucked leaf and ends
with ‘finished’, or ‘made’ tea.

3. There are six classes of tea (green, yellow,
white, oolong, black, and Puerh)
Come from same plant
The different types are the result of
differences in the tea manufacturing
process, and not due to different types of
tea plants.

4. Manufacturing procedure
 Although each type of tea has different
taste, smell, and visual appearance, tea
processing for all tea types consists of a
very similar set of methods with only
minor variations.

5. Plucking
Tea leaves and flushes, which includes a
terminal bud and two young leaves, are
picked from Camellia sinensis bushes
Collected twice a year during early spring
and early summer or late spring.

6. Picking is done by hand when a higher quality
tea is needed, or where labour costs are not
prohibitive

7. Withering/ Wilting
The tea leaves begin to wilt soon after
picking.
Withering is used to remove excess water
from the leaves and allows a very slight
amount of oxidation.
The leaves can be either put under the
sun or left in a cool breezy room to pull
moisture out from the leaves.

10. Cont…
 The process is also important in promoting the
breakdown of leaf proteins into free amino
acids
 increases the availability of freed caffeine, both
of which change the taste of the tea.

11. Disruption
 the tea leaves are bruised or torn in order to
promote and quicken oxidation.
 The leaves may be lightly bruised on their
edges by shaking and tossing in a bamboo
tray or tumbling in baskets
 More extensive leaf disruption can be done
by machinery.

13. Oxidation
 For teas that require oxidation, the leaves are
left on their own in a climate-controlled room
where they turn progressively darker.
 This is accompanied by agitation in some cases.
 oxidation occurs during the manufacture of
white, oolong, and black teas.
 Green and yellow teas are prevented from
oxidizing by steaming, drying and/or frying
techniques

14.  During the manufacture of tea, both
spontaneous and controlled oxidation occurs
 Oxidation in tea manufacture officially begins
during the withering stage as spontaneous
oxidation
 then accelerates gradually during the
subsequent steps necessary to transform fresh
leaf into finished black tea

15.  Oxidation process is often incorrectly
termed as “fermentation”
 In traditional oxidation, sieved leaf is
spread out in a thin layer (2-3 inches or 5-8
cm) on the floor of factory , on tables or
perforated trays

16.  Several chemical reactions occur
 Enzymes polyphenol oxidase and peroxidase
act on polyphenols to produce theaflavins.
 These red orange compounds react with more
polyphenols to produce thearubigins-
responsible for changing leaf’s color from
green to golden, coppery or chocolate brown

17.  Several flavor compounds produced by reaction with
sugars and amino acids
 Green Tea - no oxidation
 Yellow Tea -no oxidation
 White Tea slight, spontaneous oxidation occurs (8-15%)
 Oolong Tea- partial oxidation
 Black Tea fully oxidized
 Puerh always fermented, not always oxidized

18. Fermentation
 Fermentation is important in manufacture of Puerh
and Black tea
 Fermentation is microbial activity involving one or
more bacteria
 The leaves must be exposed to bacteria ( or have
bacteria present inherently) in order for fermentation
to occur
 exposure to oxygen during tea manufacture is often
reduced or eliminated after the withering stage for
fermentation

19.  bacteria required to both initiate and
maintain fermentation are potentially present
during several aspects of its production:
 1. On the surfaces of the leaf of the old-
growth plants themselves
 2. In the controlled environment of the tea
production rooms in which the ‘Raw’ is
temporarily stored

20.  the mounds of leaves that encourage the artificial
fermentation are stacked thickly, densely, and with
minimal surface area exposed.

21.  pile is stirred in frequently, allowed to rest
and generate the heat desired to encourage
the multiplication of microbes and the
paced decomposition of the leaf.
 Thermal blankets are often used to cover
the surface and further encourage the
process

22. Fixation / Kill-green
 is done to stop the tea leaf oxidation at a
desired level.
 This process is accomplished by moderately
heating tea leaves, thus deactivating their
oxidative enzyme

23. Rolling / Shaping
 The damp tea leaves are then rolled to be
formed into wrinkled strips, by hand
 or using a rolling machine which causes the tea
to wrap around itself.
 This rolling action also causes some of the sap,
essential oils, and juices inside the leaves to
ooze out, which further enhances the taste of
the tea

25. Drying
 Drying is done to "finish" the tea for sale. This can
be done by panning, sunning, air drying, or baking.
 The drying of the produced tea is responsible for
many new flavour compounds particularly
important in green teas

26. Aging / Curing
some teas required additional aging,
secondary fermentation, or baking to
reach their drinking potential