tea - camellia sinensis - aggie horticulture

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TEA TEA -- Camellia Camellia sinensissinensisFamily - TheaceaeGenus - CamelliaSpecies - sinensis

Tropical Horticulture - Texas A&M University

Related PlantsRelated Plants

• Ornamental Camellias


Groups of TeaGroups of Tea

• China type - C. sinensis var. sinensis– Northern slope of the Himalayan Mts– Elevated altitudes, semi-humid forest– Bush with small erect leaves with many

serrations– Flowers are borne singly– Greater tolerance to drought and low temp.– Main tea produced in China and Japan


Groups of TeaGroups of Tea

• Assam type - C. sinensis var. assamica– Southern slopes of the Himalayan Mts– Found in humid dense forest– Tree– Leaves are larger with less serrations, less

erect, and tend to droop at tips– Leaves lighter green color– Flower in clusters of 2-4


Origin and Domestication of TeaOrigin and Domestication of Tea

ChinaAssam

18331930s

Trade with Europe

1600s


Tea DomesticationTea Domestication

• China type domesticated in south China– 4000 years ago?– Spread throughout China and Japan

• Trading with Europe beginning in early 1600s– Earliest maritime explorations by the Portuguese

and Dutch– England enters trade with East India Co in mid to

late 1600s

• East India Trade Co monopoly on tea trade ends in 1833

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Tea DomesticationTea Domestication• Tea growing in India investigated

– Seed of China type were planted various locations– Grew best in Assam, NE India - so developed

plantations– Tea-like plants grew wild throughout forest in this

area - these were the Assam type tea– Initial plantings were mixtures of China and Assam

tea plants• Outcrossing plants• Seed propagation• Hybrid tea populations were developed


Tea DomesticationTea Domestication• Assam region initial area of domestication of

Assam tea– Late 1800s

• South India• Sri Lanka (esp. after rust destroyed the coffee industry)• Java and Indonesia

– 1930s• Equatorial highlands of Central and East Africa

• Current Assam tea is a hybrid type derived from the initial mixed plantings in NE India


Origin and Domestication of TeaOrigin and Domestication of Tea

ChinaAssam

18331930s


Tea ProductionTea Production

27

21

9

15

0

5

10

15

20

25

30

Percent of total

production

India China Sri Lanka Africa

Major Producing Regions

By weight 50% total production of coffee

Increasing


Tea ProductionTea Production

2168

1395

0 570

500

1000

1500

2000

2500

Prod

uctio

n (1

000

t)

Asia Europe Africa NorthAmerica

SouthAmerica

Major Producing Regions

Much of production consumed locally


Tea Tea ImportationsImportations

311

227187

104

160

50100150200250300350

Impo

rtat

ions

(100

0 t)

Asia Europe Africa NorthAmerica

SouthAmerica

Major Importers

Much of production consumed locally

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The Tea PlantThe Tea PlantPerennial evergreen bush/tree

Harvest young leaves


The Tea PlantThe Tea Plant• Understorey trees• Adaptation

– Temperature• 18-30°C• Leaf growth stops

– Below 13°C– Above 35°C– Shoot replacement cycle related to temp.

• Equatorial region– Grown in highlands (1000-3000 m)– At low latitude/altitude need shade for best growth (Assam type)

– Rainfall– Soil type


The Tea PlantThe Tea Plant

• Understorey trees• Adaptation

– Rainfall• 1150 mm if evenly distributed

– Soil type• Acid soils (pH 4.0 to 5.6)• Good drainage• Good water holding capacity


Tea Plant PropagationTea Plant Propagation

• Seed– Short period of viability– Germinate in sun and plant into pots once begin to emerge– 2-3 years before field planting size– Traditional approach to propagation– Seedlings are not uniform

• Clonally– Single node cuttings– Ready for field in 1 year– Rooted cuttings are uniform


Tea PlantingTea Planting• Density of planting

– 10,000 to 15,000/ha

• Use of shade– Initially all tea in Assam with shade– Now many areas without shade

• Higher yields without shade• Greater response to fertilizer without shade

– Some exceptions• High heat areas (lowlands of north

India/Bangladesh)• Low input system, in highlands of Kenya,

shaded system is equal or better than unshaded


Tea Training and PruningTea Training and Pruning• Training

– Head back to 20 cm at planting– Next year to 40 cm– Final year at 60 cm to form a level

“plucking table”

• Pruning– Need to cut back periodically– Plucking table will slowly rise– Periodically need to rejuvenate

• Prune below branches• Bring to bear again

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Tea HarvestingTea Harvesting• Harvest - Most done by hand

– Tips• Bud only gives best product

– Fine plucking - most common• Bud plus 2 leaves

– Coarse plucking• Bud plus 3 leaves

• Important to begin processing quickly


Tea HarvestingTea Harvesting


Types of TeaTypes of Tea

• Green Tea– Not “fermented”– Only China type tea – Mainly China and Japan

• Oolong Tea– Semi “fermented”– Produced in Taiwan

• Black Tea (highest production)

– “Fermented”


Tea ProcessingTea Processing


Black Tea ProcessingBlack Tea Processing

•• WitheringWithering–– Thin layers of leaves in traysThin layers of leaves in trays–– Leaves allowed to dry to lose turgidityLeaves allowed to dry to lose turgidity–– 1818--24 hours24 hours–– 50% weight loss50% weight loss


•• RollingRolling–– Twists and breaks up leafTwists and breaks up leaf–– Expresses leaf sapExpresses leaf sap

•• Good contact with Good contact with flavanols flavanols and and polyphenol oxidasepolyphenol oxidase

–– Done 3Done 3--5 times5 times•• 1st roll = 1st roll = dhoolsdhools, most tender parts of the leaves, most tender parts of the leaves•• 2nd and 3rd rolls = 2nd and 3rd rolls = mahls mahls and finesand fines•• Sticks left over = big bulkSticks left over = big bulk

–– Need to keep temp between 27 Need to keep temp between 27 -- 32 C32 C•• Mechanical heatMechanical heat•• Heat generated by oxidationHeat generated by oxidation

Black Tea ProcessingBlack Tea Processing

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Black Tea ProcessingBlack Tea Processing•• Fermentation = oxidationFermentation = oxidation

–– Begins with rollers, Begins with rollers, dhool dhool stagesstages–– Flavor and aroma developsFlavor and aroma develops–– Leaves turn darkLeaves turn dark

•• Flavanols Flavanols >> colored >> colored theaflavinstheaflavins, , thearubiginsthearubigins

–– Limit of 4Limit of 4--5 hours5 hours


Black Tea ProcessingBlack Tea Processing•• Drying = stops oxidationDrying = stops oxidation

–– Time of fermentation Time of fermentation •• SubjectiveSubjective•• Important in qualityImportant in quality

–– In at 82 In at 82 -- 94 C and finish at 53 C94 C and finish at 53 C–– Moisture levelMoisture level

•• 54% to 3% moisture54% to 3% moisture


Black Tea ProcessingBlack Tea Processing•• Grading and SortingGrading and Sorting

–– Broken Orange Pekoe (high % buds)Broken Orange Pekoe (high % buds)–– Broken PekoeBroken Pekoe–– Orange Pekoe (twisted tender stalk)Orange Pekoe (twisted tender stalk)–– Pekoe Pekoe -- compact and densecompact and dense–– Souchong Souchong -- compact and densecompact and dense–– Broken Orange Pekoe FanningBroken Orange Pekoe Fanning


Green Tea ProcessingGreen Tea Processing•• Prevent “fermentation”Prevent “fermentation”

–– Initial heating to destroy Initial heating to destroy polyphenol oxidasepolyphenol oxidase–– Rolled at 90Rolled at 90--100 C for 45100 C for 45--50 min 50 min -- 50% moisture50% moisture–– Rolled without heat for 15 minRolled without heat for 15 min–– Dried at 50Dried at 50--60 C (3060 C (30--40 min) 40 min) -- 30% moisture30% moisture–– Rolled on heated pan (80Rolled on heated pan (80--90 C), 40 min.90 C), 40 min.–– Dried at 80 C Dried at 80 C -- <6% moisture<6% moisture–– Sieve to remove stems and debrisSieve to remove stems and debris–– Final dryingFinal drying


Quality ControlQuality ControlUse same weight of tea per cup

Allowed to steep in hot water same time

Grade indicated by cup placement


Quality ControlQuality ControlJudge quality of tea samples

Ensure consistent flavor of blends

Tea judged better gets higher price

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Top Tea Top Tea VarietalsVarietals

• Darjeeling– First flush, light almondy, flowery scent, puckery mouthfeel– Second flush, darker, more body, hints of muscat

• Formosa Oolong– Champagne of teas, grown at lower altitudes– Aroma of peach blossoms, wisp of smokiness, almost no

mouth pucker (astringency)


Top Tea Top Tea VarietalsVarietals

• Yunnan– Full body, rich, wispy smokiness, hint of pepperiness

• Earl Grey– Flavored tea– Black tea with bergamot (citrus of Sicilian origin)

• Ceylon– Clean, bright flavor


Health Benefits of Tea


Health Benefits of TeaHealth Benefits of Tea

• Reduce risk of Coronary Heart Disease– Epidemiological studies– Lowers blood levels of LDL cholesterol

• Flavonoids are antioxidants– 95% polyphenols in tea are flavanoids– Higher anti oxidant activity than Vitamin A, C or E

- but with less bioavailability– Combat free radicals >> reduce risk of cancer

• Much of benefits not experimentally confirmed

Any questions on tea?Any questions on tea?

tea - camellia sinensis - aggie horticulture

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