How black tea is made

Black tea is just fresh leaf left to rust in a controlled way, which is why its flavor keeps for years.

stations: 7
things upstream: 1
raw source: 1
step from the ground: 1

The short version

Black tea is made from the young leaves of one shrub. After picking, the leaves are withered to lose water, then bruised or rolled so their enzymes meet oxygen and the leaf browns. That oxidation is stopped by hot-air drying. Finally the leaf is sieved into grades from whole leaf to dust.

Pluck the new shoots

Workers pick the bud and top leaves of the tea bush. Young leaves and buds carry the most caffeine, and the quality of the plucking sets the ceiling on the finished tea.

Goes in
Tea leaves
Wither on troughs

Leaves are spread on long troughs and air is blown through them, usually overnight. They go limp, lose about 35% of their moisture and start to change slightly.

8 to 14 hours
Roll or shred the leaf

Orthodox processing rolls the leaf on a ridged table, which bruises and twists it. The CTC method pushes it through spiked rollers that crush, tear and curl it into tiny pellets, which suits tea bags.
Oxidize in humid air

Bruising frees enzymes and sap, and the leaf starts to oxidize in cool, humid air. Polyphenols in the leaf turn into the compounds that give black tea its color and strength. This is often called fermentation, but no microbes are involved.

45 minutes to 3 hours at 20–30 °C
Fire it dry

Firing in hot air halts the chemistry for good. The leaf turns black and brittle, and loses nearly all its remaining water.
Sieve into grades

Screens sort the leaf into whole leaf, broken, fannings and dust. Fannings and dust have more surface area, so they brew fast, and they are what goes into most tea bags.
Blend and pack

Many black teas are blends of different estates. They are weighed into bags, tins or sacks for shipping.

End of the lineBlack tea Next it goes into kombucha.

Worth repeating

Compressed bricks of black tea served as a form of de facto money in Mongolia, Tibet and Siberia into the 19th century.
The CTC method was developed by William McKercher in 1930.
Black tea keeps its flavor for several years, while green tea usually loses its flavor within a year.