The provided diagram illustrates the various stages involved in the manufacturing of black tea, highlighting two distinct methods: the traditional approach and the modern technique. Overall, the process begins with the harvesting of tea leaves and concludes with the final drying stage, with the primary difference between the two methods occurring in the middle phase of production.
Initially, the process commences with the picking of the bud and the two top leaves to ensure high quality. These leaves then undergo a withering stage, where air is passed through them on racks, resulting in the removal of 60% of their moisture. Following this, the production path splits. In the traditional method, the leaves are rolled flat, which releases enzymes. Conversely, the modern method involves cutting, tearing, and curling the leaves, a quicker process that creates smaller granular pieces suitable for tea bags.
Regardless of the method used, the leaves subsequently undergo oxidation or fermentation, where they are spread on tiles or cement. During this stage, the interaction between enzymes and air causes the leaves to turn a copper colour. Finally, both types of tea are subjected to firing or drying in ovens or hot air dryers, which releases the flavour and aroma, ultimately removing 97% of the total moisture.