Black Tea is the most processed of all teas
The leaves are plucked and laid in withering troughs with warm air blown through. Once withered, the leaves are transferred to large rolling machines that twist the leaves in to shape between two large brass plates. As the leaves are rolled, the veins within them break releasing their natural juices, and allowing oxidisation to occur. The tea then travels on rollers to the ovens for firing.
Black tea is generally stronger than less oxidised tea and contains more caffeine. Unlike other types of tea, black tea keeps its flavour for several years and is the most popular tea in the western world.