The Production of Black Tea
Step 1: Withering
Making black tea is even more complex and time consuming than some of the others. The freshly plucked leaves are brought to the tea factory (which is often located on the tea estate, or very near most small farms). After arrival, the leaves are laid out on screens fitted to long wooden boxes referred to as “withering troughs”. Here the leaves wither, as air passes through and over the leaves, removing approximately 60% of it’s moisture content over the next 12-18 hours, prior to the leaves being “rolled”.
Step 2: Rolling
Rolling disturbs the natural cellular structure of the leaves, thus releasing enzymes present in the leaves, which then combine with polyphenols and other properties in the leaf, allowing the characteristic flavors of black tea to emerge. Descriptions of these characteristic black tea flavors vary from “flowery ” to “fruity,” “nutty,” and “spicy” -just to name a few.
Step 3: Fermentation
After rolling, the teas are moved on to the next stage of production called fermentation, which is actually the oxidation of the tea constituents. The tea is spread in layers of about 4 inches to oxidize. The chemical interactions occurring between the various parts of the plant alter the leaf from a green color- to coppery red, then to brown, and finally to a nearly black color.
Step 4: Drying
After the desired amount of oxidation has been attained, the tea is fired in large ovens, using air that has been heated to 210-250 degrees Fahrenheit. This dries the leaves to an ideal 3% moisture. The flavorful juices dry on the surface of the leaves and remain stable until exposed to boiling water during infusion, affectionately referred to as the “agony of the leaves.”
Step 5: Sorting
The last step involves sorting the finished, fully oxidized leaves by size. During the production process, many tea leaves are broken or crushed, so that the finished tea consists of full leaves, broken leaves (“brokens”) and smaller particles (“fannings”). Since the necessary steeping time increases with the size of the leaf, the tea must be sorted into lots of consistent leaf size.