How is tea made?
All types of tea come from the same plant: the camellia sinensis. How does one plant turn into so many types of teas? It's all in the details.
The variations in tea come from growing conditions and geography, as a start. But the production process plays an important role too.
In total, there are nine steps involved in turning a simple tea plant into the tea we enjoy: cultivation, pruning, plucking, withering, rolling, oxidation, firing, sorting, and packing. The withering, rolling, oxidation, and firing processes most directly influence how a tea is categorized (as black, oolong, green, white, puer, etc.). Let's take a deeper dive...
All types of tea go through a withering process. After the leaves are plucked from the tea plant, they are spread out onto trays or screens. They are left to dry, often in open sheds that let natural breezes do the hard work. During this phase, leaves lose 50-80% of their moisture and become limp—which makes them ready for the next step.
During the rolling process, the leaves are twisted into the shape suited for the tea type. There are lots of techniques for rolling tea, either by hand or mechanically. As leaves are worked through this process, their cell walls break, releasing enzymes. Before passing to the next step, rolled leaves can be passed through a roll-breaking machine that separates leaves into smaller, more consistent pieces.
Oxidation is the process of removing moisture from the rolled leaves and infusing them with oxygen. (It's sometimes, incorrectly, referred to as fermentation.) The tea leaves are spread out (no more than 2-3 inches thick) on large troughs with wire-mesh bottoms that allow continual air flow, usually in rooms at about 75-90°F and 90% humidity. Then, they are left to dry and oxidize. The longer the tea sits, the more oxygen it absorbs. Black teas are fully oxidized, undergoing a process of as much as 3 hours. Oolong teas are partially oxidized, with the length of time varying by variety of oolong. White and green teas do not undergo this process at all.
Once the desired level of oxidation has been reached, the tea leaves are exposed to a gentle heat to stop the oxidation process, as well as kill certain enzymes to stabilize the leaves and prevent molding and breakage. Firing involves blowing hot air over the leaves or running them through heat tunnels for 10-60 minutes. Temperatures range from 140 to 170°F.
By the time tea emerges from the firing process, it is ready for consumption. But before it gets to you, it will be sorted—either by hand or mechanically—to ensure consistency and packaged to be sold.
When it reaches you, the camellia sinensis is transformed—and delicious!