The tea factories found on most tea estates play a vital role in the final value of the manufactured tea. Regardless of how carefully the leaf has been grown and plucked, if the processes at the factory are not carried out properly the end result will be of a poor quality.
A tea factory is a multi-storeyed building, almost always sited on the tea estates to ensure that the time between plucking and processing tea is kept to a minimum. Once the tea leaves arrive at the factory they are spread across the upper floors of the building in troughs – a process known as withering. Withering removes all excess moisture in the leaf to make it pliable.
Once the tea leaves have been withered, they are rolled, twisted and broken up. This acts as a catalyst for the enzymes in the leaves to react; this chemical reaction occurs when the leaf comes in contact with air, which is necessary for the production of black tea. The leaves are rolled on circular tables, which are fitted with brass or wooden battens. The leaf is fed in from above through an open cylinder and as this cylinder rotates the amount of pressure applied to the leaf against the table surface is adjusted.
The leaf particles are collected after rolling and are spread out on a table where they start to ferment when exposed to warm air. The oxidisation time is dictated by the prevailing weather pattern. This brings about the changes necessary to make the tea liquor palatable. As this chemical process of oxidisation takes place the colour of the leaf changes from a green to a bright coppery colour.
The fermented leaf is then put into a firing chamber where the hot air prevents any further chemical reaction from taking place. The temperature at which the tea has been fired will determine the keeping qualities of the tea. Once the firing process is completed the leaves emerge hard and black, and are ready for grading.
Grading determines the value of the final product. The tea particles are separated into different shapes and sizes by sifting them through a progressively finer series of meshes. The various grades of tea denote only the size and appearance of the leaf and bear no relation to quality. The graded teas are finally weighed and packed into tea chests or paper sacks and dispatched to the tea brokering companies.