About Tea: Introducing Camellia Sinensis
Tea has a recorded history that spans nearly 5,000 years. Legend has it that tea was discovered in 2737 BC when some tea leaves blew into Chinese Emperor Shen-Nung’s pot of boiling water.
All tea comes from the plant camellia sinensis. Camellia sinensis is a tropical and subtropical evergreen plant native to China. Tea is best grown between the Tropics of Cancer and Capricorn, in mountainous areas 3,000 to 7,000 feet above sea level. Leading tea-producing countries include China, India, Japan, Kenya, Sri Lanka, Taiwan and Vietnam.
There are two primary types of camellia sinensis used in the preparation of the tea:
- Camellia Sinesis var Sinensis (China Jaat), which has smaller leaves (5-12cm) and is propagated widely around China, Taiwan and Japan.
- Camellia Sinensis Assamica (Assam Jaat) which has larger leaves (15-20cm). The Assamica variety is known for its large leaves and its hardiness, and is grown widely in India, Sri Lanka and Kenya for the production of black tea.
Much like wine and coffee, the environment in which the tea is grown has a significant effect on the quality and flavour of the tea.
Tea Plants can either be propagated from seeds or using grafts or cuttings. Tea propagation from seeds is not as common in large-scale production owing to the risk of the tea bush not conforming to the desired characteristics.
When plants are propagated via grafting, the new plants will be identical clones of the original plant from which the cutting is taken. This means preferred characteristics (taste, aroma, leaf size, level of disease, pest and weather resistance) will be passed on to the new tea bush and can be replicated to scale. These grafted plants are called cultivars. The word cultivar is a combination of the words "cultivated" and "variety".
The tea bush would continuously grow but goes into dormancy owing to cooler seasonal weather changes. e.g. Sri Lanka, located 8 degrees north of the equator, produces tea year round due to its warm climate and high rainfall, producing a new flush approximately every 80 days.
The first tea harvest is obtained 4 to 5 years after planting. The tea bush itself may to grow over 10 meters, but to allow for ease of harvest, tea bushes are typically trimmed down to chest 1 to 1.2 meters, with the exception of wild and ancient tree teas which are harvested using ladders. If nurtured, trimmed shrubs typically produce tea for 60 to 70 years, whereas wild trees left to grow freely in their natural habitat can continue to produce tea for more than 1700 years.
Much like wine and coffee, the environment in which the tea is grown has a significant effect on quality and flavour. The elevation, climate (rain fall, average temperature and temperature variation, winds), soil fertility & pH (ideally 4.5 to 5.8) and drainage all affect plant health and the density of cells in the leaves.
Tea typically grows within 20 degrees of the equator in tropical climates, although camellia sinensis is cultivated in over 49 countries between longitudes 42 degrees north and 33 degrees south. Tea plants grow best in regions where the temperature is around 65–77 degrees Fahrenheit, with humidity levels between 75% and 85% and an annual distributed rainfall amount between 72 and 100 inches.
Higher elevations typically provide larger variations in temperature with adequate sun and rainfall, and produce teas of higher character. This is particularly the case where dry winds reduce moisture and condense the flavours found in the leaves and plant health is sustained with adequate organic fertilisers made without the use of synthetic chemicals (typically though composting or vermiculture). This “living” soil, rich with microorganisms, is optimum for sustaining plant health.
Whilst there is significant variation with respect to the appearance, aroma, flavour and strength by the terroir of the tea, the skill and motivations of both the farmer and manufacturer producing the tea also have significant bearing on final quality and flavour, as this is likely to impact decisions concerning the cultivation method, plant material (varietal or cultivar), type of plucking and production equipment used, and approach to tea manufacturing practices (e.g. steaming vs panning to halt oxidisation, plucking standards, orthodox versus CTC processing, machine versus hand plucking, applying heat during withering, and continuous oxidisation methods).
Specialty tea honours the diverse range of qualities, growing regions, climates, production and preparation methods, and utilises best practice methods produce the highest quality and finest flavour.
Specialty tea is a term given to leafy grade tea produced with the intention of enhancing and fully expressing the flavour characteristics present in the tea. Specialty tea honours the diverse range of qualities, growing regions, climates, production and preparation methods, and utilises best practice methods to produce the highest quality and finest flavour. Specialty tea production tends to take a more artisan approach with smaller yields and higher costs than mass-produced commodity teas.
Commodity tea, which represents the largest portion of tea produced, is purchased as a homogeneous product, where the objective of production is to maximise yields and consistency for an acceptable standard of quality, whilst reducing costs. Commodity tends to place a higher emphasis on strength and consistency, with limited tolerance for seasonal variation and spikes in character resulting from peak flavour periods.
The primary type of tea sold and the way it is prepared in each country also varies. China is considered a green tea consuming country, preparing hot tea primarily in the gongfu style with a gaiwan, India is considered a black tea consuming country preparing hot tea primarily with a tea pot and adding milk and sugar. The USA consumes a variety of teas with the highest consumption being iced tea, where black and herbal teas are mostly prepared using tea bags.
Types of Tea
Tea can be broadly categorised into two groups: oxidised and non-oxidised. Oxidisation will be discussed in more detail later; essentially it refers to a series of chemical reactions that result in the browning of tea leaves and the production of flavour and aroma compounds in finished teas. Depending on the type of tea being made, oxidisation is prevented altogether or deliberately initiated, controlled then stopped.
White tea undergoes minimal rolling and processing and is not typically withered.
White tea is from the camellia sinensis plant but is typically from the early part of a new season's harvest (or flush), typically comprising of new, immature tips and leaves. White tea undergoes minimal rolling and processing and is not typically withered. Its name derives from the fine white hairs on the unopened buds of the tea plant, which give the plant a whitish appearance. The resulting tea liquor created during infusion is also typically light or whitish in colour.
Green tea is made from unfermented leaves of the camellia sinensis plant. Unlike oolong teas and black teas, green tea does not go through the oxidisation process. Heat is applied to the leaves to neutralise the oxidative enzymes before oxidisation is able to take effect. The resulting liquor of infused green tea is typically light and pale in colour, often with a green hue.
Oolong tea can be roasted to varying degrees to bring about alternate flavour characteristics (floral an aromatic to lightly toasty, to dark golden roast).
Yellow tea is made in a similar way to green tea, but after steam treatment, the leaf is smothered and left to oxidise at a slow rate, producing leaves that are slightly yellow in colour and which offer a more mellow taste than green tea. Some scientists speculate that yellow tea might be healthier than green tea: In 2013, 4 Chinese scientists published a scientific report showing the smothering process of yellow tea which produced a number of digestive enzymes that have beneficial effects on the stomach and spleen. It also showed that yellow tea has stronger antioxidant activity and anti-inflammatory properties than green tea.
Oolong is a semi-oxidised tea, with oxidisation falling somewhere in between green (not oxidised) and black tea (fully oxidised) typically in the range of 8% to 85% depending on the style of tea being made. Most oolong teas use tea plant cultivars specifically chosen to produce oolong. During production, the leaves are typically kept as whole leaves that can either be compressed into balls or rolled into whole leaf strips. Oolong tea can be roasted to varying degrees to bring about alternate flavour characteristics (floral and aromatic to lightly toasty, to dark golden roast). Less oxidised oolongs offer a more fresh green tea taste, whilst heavily oxidised oolongs present a more malty tea flavour.
Black tea is also referred to as red tea in China owing to the colour of the liquid. In contrast, the English term black tea refers to the colour of the oxidised leaves. Black tea is considered to be fully oxidised, although there is still a range of oxidisation possible in manufacturing black tea. To produce black tea, the tea is rolled and left to rest (typically for a period of 2 to 2.5 hours) in a warm damp environment to promote oxidisation. Heat is applied to the tea once the desired level of oxidisation has been accomplished.
Shou Puerh undergoes a secondary fermentation process which takes only months to complete, and produces a tea similar to that of the naturally aged Sheng Puerh, but with less complexity.
Puerh is a type of fermented tea originating from Yunnan province in China, where it has been grown and consumed by the many ethnic tribes in the region for at least 1,750 years. During the Tang Dynasty (618–906 AD), tea producers formed the tea into compressed cakes which allowed the tea to be transported without breakage when being shipped to trading destinations. Over time Puerh tea was pressed into various different shapes including discs (bing), bricks (zhuan), birds’ nests (tuo), square (fang), mushroom (jin), melon (jingua), or can be left loose (san).
Puerh comes in two varieties, the traditional raw (sheng) tea, or cooked (shou) tea. Sheng Puerh requires ageing to fully mature and turn into a rich brown/black colour. This process can take 10+ years and helps develop complex characteristics as it ages. Shou Puerh undergoes a secondary fermentation process which takes months to complete, and produces a tea similar to that of the naturally aged Sheng Puerh, but with less complexity.
Only beverages containing camellia sinensis are considered tea. Herbal infusions that do not contain camellia sinensis are not teas. Oolong tea, black tea, chai tea (if containing black tea) are considered teas, Peppermint, chamomile and lemongrass are considered herbal infusions or tisane (pronounced ti-zahn) as distinct from tea. The word tisane is derived from the Greek word "ptisane".