Tea Plant - Camellia sinensis
Tea is made by steeping the leaves and buds of the Camellia Sinensis (L.) Kuntze plant, an evergreen plant which grows in tropical and subtropical climates.
The tea tree has been known to the Chinese since the immemorial, but in the West the first scientific description of it was written in 1712 by Dr. Kaempfer a physician with the Dutch East India Company, who called it Thea japonense. Some 40 years later, in his master work Species Plantarum, which lists all the plants then known to man, Carl von Linnaeus renamed it Thea sinensis. At a later date he distinguished between two different varieties: Camellia japonica and Camellia sasanquea. Note that, at the time, there were two accepted terms to define the plant: Thea and Camellia. It was not until 1959, after numerous debates among botanists, that the name Camellia was officially adopted by the International Code of Botanical Nomenclature. The term Camellia is an homage to a Moravian Jesuit called George Joseph Kamel (1661-1706), who studied botany in Asia at the end of the 17th century. The adjective sinensis was added by Linnaeus. The letter “L” also refers to the initial of Linnaeus, while “O. Kuntze” is the name of the botanist who, in 1881, combined them all to create the scientific name.
When we think about tea plant we think it is a shrub, however if it is not pruned it can grow as tall as around 10 – 15m. There are many age old trees in Yunnan province where tea originate from, some of them are over 3000 years old.
Ancient Chinese history reveals that the leaves of the wild tea plant were first used for medical purposes until the first established plantation in 4th century AD where the plant was “tamed” from tall tree into a shrub for ease of harvesting.
Indeed, by pruning the top buds, the plant grows outwards rather than upwards.
The leaf tea is simple, symmetrical, either oval or lance-shaped, with serrated edges and midrib.
The Tea plant:
Among the 200 species of Camellia theaceae registered today, only one – Camellia sinensis, is used to produce tea. This species includes 3 main varieties:
sinensis means “from china”- this is the most ancient variety which can grow up to 6m. Its small, dark leaves are light in body. It is a sturdy plant that has greater resistance to cold and drought than other varieties, so it is often grown at hight altitudes as well as in regions with difficult climatic conditions, such as parts of China, Japan, Iran and Turkey. Its productive life is long and in some conditions can last well over 100 years.
assamica – Discovered by Scottish Major Robert Bruce in the region of Assam, India, in the first half of the 19th century. This variety is grown extensively in India, Africa and Sri Lanka. Highly suited to a tropical climate, it is grown mainly on plains and regions that enjoy abundant rainfall.
Less aromatic than sinensis leaves, its large, thick leaves produce a liquor that is quite robust and very dark when oxidized. Assamica is the tallest of the C. sinensis varieties. In the wild, some trees can grow to a height of 30m. Under plantation conditions, however, the productive life lasts no longer than 30-50 years.
cambodiensis – Large and flexible, the leaves of cambodiensis can grow to a length of 20 cm. This variety is not as good as sinensis or assamica but thanks to its excellent capacity for natural hybridization with the other two varieties, it is occasionally used to create new cultivars.
The tea plant reproduces through:
Variety (seeds) – developed naturally – each plant is different from the next, and therefore every new plant will have a different genetic make up to that of the parent plant.
Clone (cuttings) - is a type of plant that has been propagated through cuttings. A cutting/clone has an identical DNA to that of the parent plant.
Cultivar/Hybrid – developed by man - A cultivar is a ‘cultivated variety’ and in theory could be either a clone, or a plants produced through seed, but it is a term used from a human-use standpoint, not a biological one.
Cloning plants that resist certain climatic conditions and pest attacks, or simply the most productive or those that produce high quality teas, guarantees consistent level of production.
The Cultivar: the term “cultivar” is used to define a plant species that was created through hybridization or mutation and selected for its specific characteristics. As these characteristics are not necessarily transferable by seeding, the cultivar must be reproduced through cuttings in order to retain the same genetic profile.
In addition to the choice of plant material, growing season and quality of the picking, the characteristics of a plantation – its soil, climate, altitude, latitude – are important factors that greatly influence the quality of a tea. Each region has specific agricultural properties, so the same tea tree will produce different-tasting teas depending on the conditions in which it is grown. The Plant will constantly adapt to its environment, producing substances that, notably, can create interesting flavours. The notion of a “terroir” helps define the specific characteristics of a particular region or expanse of land, by examining its soil, climate, altitude and latitude in combination with the expertise of the local growers.
Soil: The tea will adapt to the land, however, for optimum growth, it needs an acidic soil (pH 4,5 – 5,5) because acidity will help it absorb nutrients. Ideally, it should also have a soil that is rich in minerals (nitrogen, potassium, magnesium) and covered with a deep layer of humus. It likes well drained soil.
Climate: The tea tree grows best in a tropical or subtropical region. It needs plenty of rain (1500mm minimum). The ideal average temperature is around 18-20 C, with a minimum of 5 hours of sunshine a day and humidity of 70 - 90%. Tea is not resistant to frost with exception of some cultivars.
Altitude: Steep slopes of high mountain ranges in Asia produce tea of unrivaled quality. While the difficult climatic conditions found at these altitudes can stunt the growth of a tea tree, they are excellent for the development of aromas. Warm days give way to cold nights, and sun exposure is often reduce to a couple of hours a day because of the constant mist. Under these conditions the tea tree's growth is slowed, but the new shoots it produces carry a higher concentration of the aromatic oils that create richer flavours.
Latitude: Tea is perennial plant and in certain regions close to the equator, its leaves can be harvested all year round. But in regions located beyond 16 degrees north or south, where daily sunlight is less than 11 hours for a period longer than 5 weeks, the tea tree's growth will slow down and it will become dormant. This period of dormancy is highly favourable for the production of good-quality tea. When the plant awakens in the spring, the aromatic ingredients it secretes are more concentrated and often confer and exquisite taste to the tea from the first harvests of the year.
The plants that grow in tropical and subtropical regions marked by a mild climate, and the optimal proportion of humidity, rain and sun, produce the highest quality teas.
2) Low altitudes – high temperatures high humidity (Camellia sinensis assamica)
1) The Tea plant requires a well-drained acidic soil and rainy, cloudy, foggy and mildly sunny climate. The best teas are produced in the mountains, where the plantations enjoy the best conditions in which to grow, steep slopes drain the soil so the roots are not standing in water. Under the shaded sky the plant produces more amino acids hence the aroma of the tea. These teas are appreciated for their freshness and their lingering aromatic notes, suitable for multiple infusions. In these areas plucking is mostly done by skilled hand, which allows the plucker to choose the best shoots. Bush and leaves are less damaged than in mechanical plucking.
2) For plain-growing teas, it is important to shade the plants, creating the optimal undergrowth conditions for their growth. In nursery the tea is shaded by bamboo laths. After planting into field they are being shaded by nitrogen releasing trees. On plains tea can be harvested mechanically, which is used widely in Japan, however this method of harvesting does not allow fine plucking and leaves has to be sorted late in factory.
Cuttings are taking from mother bush and planted into nurseries which are shaded by bamboo laths. It takes 3-5 well cared years for the bush to be replanted into the field and produce shoots. After this period the tea bushes are regularly pruned so they grow no higher than 1m, thus making it easier to harvest the leaves. In addition to stimulating the growth of new shoots, pruning called “shaping” forces the plant to branch out and develop along a horizontal plane called “plucking table”. Through 30-50 years a tea tree will undergo regular pruning to help maintain a healthy yield.
The quality also depends on the harvest season. Spring is by far the best as the plant has awaken from a dormant period. At this time the buds are light green, smooth, full-bodied and with a good water content, and are rich in aromas and highly antioxidant and nutritional substances. The tiny hair on the buds are protection against attacks from insects.
In China, Darjeeling, Assam, Japan and Europe the tea bush is producing new leaf shoots only in warmer seasons.
In Nilgiri, Kenya, Sri Lanka and Indonesia as these are closer to equator the plant producing new leaf shoots whole year around.