Black Tea Production

Britain’s favourite type of tea is still black tea, according to reports. However, it is speciality loose leaf tea in particular which is increasing in popularity. Take a look at what it takes to produce the finest black teas from around the world while still being cheaper than a cup of coffee, a glass of wine or even a bar of chocolate …

Black tea originates from China where it is also known as red tea. The most important element in growing tea is of course the Camellia Sinensis plant itself. There are various strains and varietals of the tea bush which in different climates and geographic environments give us the many variations of leaf that are grown – in size and shape and flavour.  Yet although all tea come from the same plant, it is the way that the leaves are then processed methods that determines which type (colour) of tea is produced.

Plucking Tea Leaves

Black Tea Processing Steps

Picking and Processing Black Tea

It is still mainly women who pluck the fresh green leaves thanks to their delicate hands. Tea pluckers collect the leaves in a basket or linen. The pluckers follow strict rules of only picking two leaves and a bud.

The leaves are then examined and weighed before being put through five different processes. It is essential that the tea is transferred to the factory as quickly as possible after being picked. This prevents it from oxidising too much. Factory windows are kept open and fans are used to ensure the tea remains cool while waiting to be processed.

Did you know it takes around 50KG of freshly plucked tea to make 12KG of final product?

Withering Black Tea

Withering is the first and most basic stage of black tea production and is one of the most crucial. This is where the water content is removed from the leaves until they have lost approximately 30% of their humidity.

Modern withering is mostly conducted in large wired troughs on which the leaves are laid and where they are carefully aired from below and above to with large ventilators to gradually reduce their innate moisture. Some warming may be introduced, if necessary, to reduce the withering time at busy times or where there is very high water content.  This may take 8-12 hours.

More traditional natural withering processes means that the leaves are spread out on laths which are covered with jute, wire or nylon nets. This process can take slightly longer and depending on the weather and humidity content of the leaves, can take between 14-18 hours.

Tea Rolling

When the correct moisture content has been achieved, the leaves are then rolled to promote oxidation.  There are two methods of tea rolling, the Orthodox Method and the CTC (Crush-Tear-Curl) method.

Orthodox Tea Manufacturing Process

Rolling will cut open the still green leaf and push out cell sap, promoting the enzymatic oxidization of polyphenols. The released cell fluid reacts with the oxygen in the air. This process takes 30 minutes each and is repeated 3 times. This is a basis of forming black tea’s aroma, colour and flavour. The sign of a twisted leaf often denotes good production as does a glassy finish to the leaf.

CTC Method (crush-tear-curl)

The leaves are rolled for 30 minutes, during which time the entire leaf is torn in specially constructed thorn drums. The stems and leaf ribs are separated as far as possible and only the torn “meat” of the leaves is processed further. Processing tea in CTC machines produces a much finer end product and gives much higher yields compared to the orthodox production method and is often used for fast growing teas and is mostly considere to be of a lesser quality than Orthodox. Due to the large internal demand in India, this method is used for 50% of their entire processing today (mainly Assam) and much of Kenya tea, where climatic conditions means tea grows most of the year and very fast.

Black Tea Fermentation

The oxidation and fermentation begins as soon as the two leaves and a bud are picked however it is sped up during the rolling process. Fermentation is the key process determining black tea’s quality.

The leaves are spread out on large boards in 10-15 cm thick layers in a special room.  This room has a temperature of 40°C for 2/3 hours. Additionally, water may be sprinkled on the leaves. This is when the leaves go from green to a copper-red to brown colour. It creates the unique aroma which is rediscovered when you infuse the leaves. The correct fermentation is very important for the final quality of the tea.


When optimum fermentation is reached, the leaves are put through tiered dryers on metal conveyor belts to halt the oxidation process. The tea is dried for approximately 20 minutes with hot air of 80-90°C which makes the cell fluid stick to the leaves. This changes the leaves colour from dark brown to black. The final humidity of the leaves is between 3-6%.


A mechanical sieving process sorts the finished tea into common grades. The grading terms don’t refer to sensory aspects of the tea – they don’t describe the body, texture or aroma of a tea – but they give information about the appearance of the leaf that may be helpful when you are buying tea.

Your average tea bag is likely to contain a blend of teas. Which can consist of over 25 different black teas. It’s likely to be the lowest grade such as OF compared to a Darjeeling First Flush which may be FTGFOP1.

Tea Grades Explained

OP: Orange Pekoe
FOP: Flowery Orange Pekoe
GFOP: Golden Flowery Orange Pekoe
TGFOP: Tippy Golden Flowery Orange Pekoe
TGFOP1: Tippy Golden Flowery Orange Pekoe One
FTGFOP: Finest Tippy Golden Flowery Orange Pekoe
FTGFOP1: Finest Tippy Golden Flowery Orange Pekoe One
SFTGFOP: Special Finest Tippy Golden Flowery Orange Pekoe
SFTGFOP1: Special Finest Tippy Golden Flowery Orange Pekoe One


For broken leaves, the letter “B” is added to the name as in BOP (Broken Orange Pekoe), FBOP, GBOP, TGBOP, etc.

For standard teabags, Fannings and Dust grades are used, for example: OF, OPF, FBOPF, FD, GD.

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