Black tea constitutes by far the largest proportion of the total world tea production. It undergoes a full fermentation (oxidation) which turns the leaves black and gives the tea its rich taste.
After picking, the leaves are spread out on open grids around which ventilation fans allow air to circulate and ‘wither’ the leaves (12-18 hours) until they become soft enough to roll. Rolling, generally between two large heavy metal plates, breaks open the membranes containing cell fluids which are exposed to oxygen in the air. Now fermentation begins, along with the development of the essential oils which determines the flavour and scent of the tea.
The rolled leaves are transferred to a humidified fermentation room where they are carried across a ventilated conveyer, through which oxygen is introduced and thus speeding up the fermentation - oxidation and tanning of the cell fluids. This process takes 2-3 hours of careful observation during which the leaves change their colour and the scent established. The quality of the finished tea is decided at this stage.
The drying process is carried out by the leaves passing through tiered dryers heated by wood or oil. The cell fluids bind to the leaves at a temperature of 90°C (20 minutes) dropping to 40°C and 6% humidity level. The dried-on cell fluids are only released again when infused with hot water.
Finally the black tea is shaken through ‘sieves’ into Grades: Leaf Tea, Broken Tea, Fannings and Dust.
Tea is graded according to leaf size, not quality. To a lesser degree a grading does reflect the taste (e.g. flowery).
Two categories are graded: Leaf Tea and Broken Tea
- FOP – Flowery Orange Pekoe: A thin, wiry leaf with tips. Tips are the golden or silver-coloured leaf tips, or buds, which contain less tannin and therefore do not darken during fermentation. Indicates that young leaves have been used.
- GFOP - Golden Flowery Orange Pekoe (Darjeeling)
- TGFOP - Tippy Golden Flowery Orange Pekoe (Darjeeling)
- OP - Orange Pekoe: A long, wiry leaf, larger than FOP. Orange originates from the Dutch ‘Oranje’, meaning royal.
- P and FP – Pekoe and Flowery Pekoe: The leaf is shorter and larger than Orange Pekoe, more open and not so finely rolled. Pekoes are stronger in the infusion than the Orange Pekoe.
- Flowery Broken Orange Pekoe – FBOP: This tea has the greater aromatic qualities of small leafed teas. A well structured, well rolled leaf with many tips and an attractive appearance.
- Golden Broken Orange Pekoe – GBOP: A very fine and strong tea – refers mainly to Assam.
- Broken Orange Pekoe – BOP: A well structured leaf with fewer tips than FBOP - and stronger.
- Broken Orange Pekoe 1 – BOP1: Some Indian plantations grade FBOP tea as BOP1. In Ceylon it is a semi-leaf tea, somewhere between OP and BOP.
- Broken Pekoe – BP: Tea produced through the CTC method (crushing, tearing and curling) usually used for teabags. The other grades are Pekoe Fanning - PF and Pekoe Dust – PD.
A few examples:
SFTFOP1: Super Finest Tippy Golden Flowery Orange Pekoe - large Leaf
FP: Flowery Pekoe - small leaf
GFBOP: Golden Flowery Broken Orange Pekoe - fine broken
BOPF: Broken Orange Pekoe Fannings - fannings
CTC: Crushing Tearing Curling - round leaf