Tea was allegedly discovered in China around 2700 BC by emperor Shen Nung, who was reputed to be interested in hygiene and medicine, and observed that people who drank boiled water enjoyed better health. Whilst sitting in his garden suffering from the excesses of over-eating, the emperor would drink from a pot of hot water on a charcoal fire in an attempt to ease his discomfort. On one occasion some leaves from an adjoining tree fell into the imperial receptacle unnoticed and he consumed the drink. Astonishment at the taste and delight when the pains disappeared resulted in the birth of tea.

It took over 3000 years for tea to become a popular drink throughout the Chinese empire, during the Tang Dynasty 600-900 AD the government recognized it's popularity by placing a tax on it.

Until the second half of the 19th century, tea for drinking was made by a process currently used for green tea. In this process the green leaf is steamed and rolled, and then dried in a furnace. It was this tea that was introduced into Europe in the 17th century, together with the habit of adding sugar to remove the excessive bitterness of the tea.

The Dutch were the first to drink tea in Europe, shipping it in 1610, with the introduction to Britain around 1650. Arriving a few years after coffee had reached England it was through the coffee houses that the new drink spread to the people. However, it was not until the early part of the 18th century that it became a common beverage for the upper and middle classes. This first tea used in England originated from China and it wasn't until the 19th century that tea growing spread to Formosa and indigenous tea was discovered in Assam. In 1839 the first Indian tea was sold in London. The first tea in Africa was planted in the Cape in 1687 but did not progress until the latter part of the 19th century. The 20th century has seen the spread of tea in Africa, notably in Kenya. With the development of India, Ceylon and Java tea industries, the style of manufacture changed from green to black tea.

The UK remains the largest importer of tea followed by Pakistan, Russia and the USA (1996).

Tea manufacture is the process of converting young fresh green tea shoots into dry black or green tea. Tea production involves a number of processes summarized and detailed below:

Plucking: the new growth is picked, usually by hand. Withering: the leaf is allowed to dry slowly and becomes more pliable.

Rolling: the softened leaf is rolled, resulting in a large and wiry end product....or

Crushing: the leaf is crushed, shredded and rolled, resulting in a granular end product.

 

Fermentation: the green leaf oxidizes, changing in both colour and flavour.

 

Firing: the tea is dried at high temperature to stop fermentation and reduce moisture.

 

Cleaning: the coarse stalk and large leaf is removed from the dried tea. Sorting: the leaf is passed through a series of meshes to produce standard grades.

 

Packing: the graded tea is bulked in silos and packed into paper sacks.

 

Plucking

Tea bushes 'flush' continuously during the season, with new shoots produced at the level top of the bush, or plucking table. Only the stems at the correct stage are plucked, and each bush is plucked every six or seven days. The fineness of plucking determines the amount of woody material in the made tea. The stems of the tea are visible as coarse 'stalk', which is hard, woody and squareish in section; the longer the stem that is picked, the coarser the stalk.

The veins of the leaves produce 'fibre', which is thinner and more whiskery in appearance. The younger leaves have less and softer fibre, whereas the older leaves have more and harder fibre. The finer the plucking, i.e. the higher the proportion of young leaves, the lower the proportion of stalk and fibre in the final made tea.

The expression "two leaves and a bud" is universally used in the tea trade to describe the shoot and two youngest leaves on a particular stem that is to be plucked. The longer the stem that is plucked, the higher the proportion of older, coarser leaf, and the lower the quality of the tea.

The plucking standard of two leaves and a bud has traditionally been seen as an ideal compromise between the conflicting requirements of quality and yield, but many producers now pluck three and a bud, and sometimes four or more. The word "tip" is traditionally used to describe the shoot, both in the green leaf and the made tea. In certain types of black tea this golden tip is clearly visible and highly sought after; the use of the word 'tippy' is universal in describing this type of tea.

Withering

When the fresh leaves are plucked they are firm and glossy, and quite easily damaged. Before the next stage of manufacture, moisture must be removed from the leaves, and this usually is achieved by blowing air through troughs containing the fresh leaf. This process may take up to 14 hours, and the result is a soft pliable leaf.

Rolling (Orthodox tea)

The withered leaf is rolled under light pressure to create a twisted, wiry appearance in the final product. Specialty teas such as Darjeeling are made in this way.

Crushing (CTC tea)

The withered leaf is shredded and then crushed between sets of grooved rollers to produce a small granular final product. This type of manufacture is used for most of the tea used in UK blends, and is ideally suited to teabags.

Fermentation

The rupturing of the leaf cells by rolling or crushing brings together the leaf polyphenols and polyphenol oxidize enzyme. The oxidation of the polyphenols give rise to the distinctive black tea flavours, and is known as fermentation. During this stage the leaf colour changes from bright green to coppery brown. The fermentation period is usually between 60 and 90 minutes, and control of this process is vital. Under-fermented tea tastes green and harsh, and over-fermented tea tastes flat and stewed.

Firing

The fermented tea is dried at high temperature to stop the oxidation process and reduce the final moisture content to below 3%. Under-firing leaves the tea with too high a moisture content, and over-firing causes a distinct burnt taste; slightly high-fired tea is seen as desirable in certain markets.

Cleaning and sorting

The dried tea is a mixture of black leaf fragments of various sizes, fibre and stalk. Tea has traditionally been sold to consumers in loose form (and still is in most consuming countries), and is therefore processed to remove the stalk and fibre and sort the tea into various homogeneous grades, such as 'Pekoe Fannings' or 'Pekoe Dust' (bulk tea is marketed using recognized standard grades such as 'PF' and 'PD'). Tea of indifferent quality and containing a high quantity of stalk and fibre can be cleaned at this stage to produce a final graded product of identical appearance to that produced from higher quality leaf. The process of cleaning and sorting is quite harsh, passing the tea through a number of metal meshes, and causes deterioration in the taste of the tea. It is a well known fact that unsorted tea fresh from the drier ('drier mouth' tea) has a much better flavour than the same tea after sorting. It is therefore quite possible that tea with a small amount of soft fibre and even a little stalk will have superior taste characteristics to a very black tea.

The stalk and fibre resulting from the cleaning process is usually bulked and sold separately as secondary grades at low prices. These are bought by packers and blended with primary grades to reduce cost; such blending is usually the cause of stalky blends, rather than a general use of poor quality tea.

Packing

The cleaned and sorted tea is packed into paper sacks or wooden chests for onward transport. The process of tea manufacture means that tea will be several months old before reaching the consumer and during this period the fresh characteristics will have deteriorated. It is now possible to buy vacuum packed tea from a few selected estates in India and Kenya. In this process the tea is packed within hours of manufacture to maintain its freshness and is usually described as "Extra Fresh".

A multitude of factors determine the quality of tea, like geographical location, altitude, climate, seasonality, planting stock, soil quality, methods of manufacture and quality of management. One of the main categories of classification is by origin. The main production origins plus a short description are listed below: