Black Tea is fermented tea. Although the varieties of black tea and methods of processing differ considerably between the producing regions, all involve four basic steps after harvesting the leaves; withering, rolling, fermenting and firing.
Withering – the leaves are spread out on trays so the air can circulate around them, thus removing the moisture. The leaves become limp ready for rolling and the leaves have a fruity aroma.
Rolling – this breaks the leaves lightly and releases the enzymes within them that are essential to the final colour and flavour. This can be done by hand or mechanically.
Fermenting – the rolled lumps of tea are broken up and spread out, then left to cool in a humid atmosphere for up to 4 hours. This causes the leaves to change from green to coppery-red; this also changes the flavour as the enzymes and oxygen transforms catechins into thearubigens and theaflavins.
Firing – this stops the fermenting process and dries the leaves, changing them from rusty-brown to black. It is during this process that the recognisable tea smell is acquired. Firing is traditionally carried out in large pans on open fires or in hot air tunnels.
After firing, the dried tea is a jumbled pile of leaves stalks and tea dust. This is then sorted by mechanical or manual sifters using graduated mesh and is separated by size. This ensures both a good appearance to the tea and even brewing. Black tea is graded according to the size of the leaf, not quality.
There are two main grades of black tea, leaf or broken. Subdivisions of leaf grade include Orange Pekoe, Pekoe and Souchong. There are three different types of Chinese Black Tea, Souchong Black Tea, Congou Black Tea and Broken Black Tea. Broken Black Tea is commonly found in instant tea and most tea bags.
“Tea gives one vigour of body, contentment of mind, and determination of purpose, when taken over a long period of time.”
Lu Yu – The Sage of Tea 8th century