Sencha (Camellia sinensis)



Updated 4 January 2024

Other botanical names

  • Thea sinensis

Common names

  • Common tea

Common origins

  • India, cultivated in Asia, East Africa, South America

Botanical classification

  • Kingdom: Plantae 
  • Division: Magnoliophyta 
  • Class: Magnoliopsida 
  • Order: Theales
  • Family: Theaceae 
  • Genus: Camellia

Components

  • Condensed catechic tannins (higher in green tea) and hydrolysable gallic tannins: epigallocatechin gallate (EGCG).
  • Flavonoids
  • Theaflavins (especially in black tea) (the younger the leaves, the richer in phenolic derivatives)
  • Purine bases (alkaloids): caffeine (more important in black tea), theine
  • Xanthine bases: theophylline, theobromine
  • Phenolic acids
  • Essential oils
  • Vitamins: B1, B2, C, E
  • Minerals and trace elements: potassium, magnesium, fluorine, etc. 
  • Amino acids

Parts used

  • Young leaves, unfermented (green tea) or fermented (black tea)

Organoleptic properties

  • Odour: herbaceous, sometimes seaweedy 
  • Taste: bitter, astringent, notes vary greatly depending on the tea

Properties

Internal use

  • Tonic, CNS stimulant
  • Hypertension
  • Vasodilator
  • Activates blood circulation
  • Inhibits platelet aggregation
  • Improves memory and concentration
  • Astringent
  • Anti-diarrhoeal
  • Diuretic

Special properties of green tea

  • Powerful antioxidant
  • Angioprotective
  • Anti-inflammatory
  • Immuno-stimulant
  • Lipolytic
  • Accelerates metabolism and tissue oxygenation
  • Antibacterial

External use 

  • Anti-pruritic
  • Anti-inflammatory
  • Antimicrobial

Indications

Internal use

Specific indications for green tea

External use

Precautions / Contraindications

  • No known toxicity.
  • Heavy drinkers of black tea (several litres a day) may experience symptoms such as palpitations, agitation, tremors, dizziness, digestive problems (nausea, vomiting, dyspepsia), nightmares and weight loss.
  • Not recommended for people with high blood pressure.
  • Drinking tea partially inhibits the absorption of iron, especially from plant sources.
    • It is also recommended to drink Sencha tea outside of meals to preserve the iron in the body.
  • To help you fall asleep at night, it is best to drink sencha tea during the day before 5pm.
  • It is not recommended for pregnant or breastfeeding women or children.

How to use / Current dose

Internal use (preferably green tea)

  • As an infusion
  • In leaf powder capsules: especially for slimming cures.

External use

  • As a mouthwash or gargle (infusion): for sore throats and mouth infections. 
  • As a compress (infusion): for tired eyes.

To learn more about teas

Traditionally, teas are classified by colour, which varies according to their degree of fermentation (a partial enzymatic oxidation obtained by withering and kneading, which acts on the phenols). This fermentation, together with the variety and the time of harvest, changes the composition, appearance, smell and taste of the tea. There are 6 types of tea (sometimes fewer, depending on the source):

  • White teas: unfermented (the least processed, just withered and dried)
  • Green teas: unfermented
  • Blue-green teas (wulong): partially fermented
  • Yellow teas: partially fermented
  • Red teas: fermented (known in the West as black tea; "red tea" is rooibos, which is not tea but comes from another plant (Aspalathus linearis) that grows in South Africa.
  • Black teas: post-fermented

Quality teas are always made by plucking the buds and no more than the first three leaves from high-altitude bushes.


Additional information

Habitat and botanical description

It is a shrub that can grow up to 15m tall in the wild, but no taller than 1.5m in cultivation. Its dark green, elongated, evergreen leaves are soft and downy when young, becoming tough and hairless as they age. The white flowers, with 5 or more petals (3 cm) and numerous yellow stamens, are fragrant. They are similar to those of the camellia, another plant of the same family. The fruits are trigonal capsules containing one or two seeds. Its roots have the peculiarity of burrowing deep into the ground, up to 6 metres below the surface.
It grows in hot, sunny, humid climates with regular rainfall. It can be found at altitudes of up to 3,500 m.

Harvest time

In general, the buds and first leaves are harvested from shrubs that are at least 3 to 5 years old. The concentration of phenolic compounds is highest in summer.

Mythology / History / Anecdotes and traditional virtues

There is evidence that tea has been used in Asia for many thousands of years, perhaps even longer. Legend has it that the first Chinese emperor, Quin (220 BC), was drinking a cup of hot water in his garden in the evening when tea leaves were added and he found the drink fragrant and soothing. Long before it was used as an infusion from the 14th century, it was first prepared as a cake of crushed leaves, then boiled with other foods or as a medicinal potion, then in the form of compressed leaves ('bricks') boiled and decocted. It was imported to Europe in the early 17th century, but was initially reserved for intellectuals.
In Asia, tea-making is an art form in its own right, alongside painting, poetry and other arts. Today, tea is the second most consumed beverage in the world after water.