Black tea is grown in China, India, Sri Lanka, and Africa, and is the most common type of tea in the Western world. The leaves range in color from brown to black, often with golden or silver tips. The bright copper liquor has a full, round aroma, and a flavor ranging from malty to flowery.

Black teas are fully fermented tea leaves.  The leaves are allowed to fully oxidize (enzymes in the tea leaves react with the oxygen in the air and start to oxidize).  This process creates the dark color of the tea leaves as well as the increase in caffeine levels.  Black teas have the highest level of caffeine compared to the other tea types. The oxidation process gives black teas more complexity than the other tea types.  They are usually more full bodied and round and less vegetal  than the other tea types.

The Oxidation (Fermentation) process of Black tea consists of:

Withering – The tealeaves are spread in thin layers on racks and left in a warm room for about 24 hours.  Circulating warm air reduces the moisture content of the leaves by half, softening the leaves so that they can be rolled without breaking.

Rolling – Traditionally the leaves were rolled gently between the hands to break down the cell walls in order to release the enzymes that start oxidation. These days, a machine crushes the leaves between rotating metal discs.

Grading – Next, the leaves are sorted according to size and if whole or broken. Grading classifies leaves by size and condition, with the best grades comprised of the bud and top one or two leaves of each shoot.

Oxidation – This is a natural process that alters the chemical structure of the leaf, allowing key flavor characteristics to emerge. The essential oils, which have been released by the rolling process, react with the air. Temperature, humidity, and time are the factors that must be controlled during this process.  Varying the length of time is one way to change the character of the tea. The longer the leaf oxidizes the softer its taste, the deeper its color and the higher its caffeine.  Black teas are FULLY fermented.

Drying – The leaves are steamed or heated to halt oxidation and begin drying.  The highly skilled tea-maker can sense when the tea is done. If it is under-fired then it will mold with time, and if over-fired, it will lose its flavor or taste burnt. 

If you have over-steeped your black tea, the addition of milk will kill the astringent taste of too much tannin. The caseins (a protein) in milk render the tannins insoluble, and carry them through your body. Never use cream in your tea, as it has too high a fat content and tends to curdle.