The four stages every green tea passes through
Every green tea, whether it ends up flat and glossy or long and needle-shaped, has gone through the same four stages: a fixative step that stops oxidation, a shaping step, a drying step, and a sorting step.
The order is fixed. The way each step is done is what makes the difference between a Longjing and a Sencha, between a Biluochun and a Maofeng.
On a factory floor those four stages may be 12 separate operations, but the underlying logic is the same in every green tea factory in the world.
Once you understand the four stages, you can read almost any green tea’s origin and grade from a few leaves in your hand. The shape tells you the rolling method, the colour tells you how the firing was done, and the aroma tells you how much care went into the final sorting.
Most of what people call regional character is in fact processing character. The leaf sets the upper limit. The processing decides where on that limit the tea lands.
Plucking and the leaf that arrives at the factory
Plucking in China follows one of two patterns. The traditional pattern is single buds or bud-and-first-leaf, picked in early spring when the leaf is small and the amino acids are at their peak. The bulk pattern is mechanical or two-leaf-and-a-bud, picked slightly later and in larger volume.
A premium tea like Biluochun is plucked almost entirely by hand, one bud at a time. A commodity grade is often machine-harvested in a single afternoon.
Once plucked, the leaf needs to get to the factory before the temperature of the leaf pile itself starts driving oxidation. A premium lot has two to four hours to reach the kill-green step; a delayed lot loses character.
A leaf that has been sitting too long before the fixative step will not be a complete loss, but it will already be on the way to a more grassy, less sweet cup. This is one of the silent differences between factory and small-lot processing.
Premium Longjing uses single buds harvested in early March. Biluochun uses a bud and one leaf, no larger. Maofeng allows a slightly larger bud set, typically two leaves or one bud and two leaves.
Kill-green, the step that decides what kind of green tea this is
Kill-green, sometimes called shaqing or fix-green, is the step that defines green tea. It is a brief, high-heat treatment that deactivates the polyphenol oxidase enzymes responsible for oxidation.
If this step is done well, the leaf stays green and the cup tastes fresh and sweet. If it is done badly, the leaf turns brown at the edges, the aroma goes dull, and the cup picks up a raw, grassy note that no later step can fix.
There are three main kill-green methods: pan-firing in a wok or drum, steam treatment in a short-blast steamer, and hot-air fixation in a chamber. Pan-firing gives the rounded, mellow character of Chinese pan-fired greens. Steaming gives the brighter, more vegetal character of Japanese Sencha.
Most large factories now use drum or hot-air equipment because it is fast and consistent. Smaller factories and premium lots still use hand wok-firing, partly for tradition and partly because it does produce a slightly different cup.
Typical pan-firing temperature is 200 to 220 °C for two to four minutes per batch, with the operator adjusting the heat as the leaf loses moisture. Drum fixation uses 130 to 150 °C with a residence time of three to six minutes.
Steam fixation is faster: forty to sixty seconds in a steamer jet at roughly 100 °C. The leaf emerges brighter and softer than pan-fixed leaf, which is why Sencha looks and steeps differently from a Longjing.
Rolling, drying, and the finishing work
Rolling shapes the leaf and breaks the cell walls enough to release the juices during brewing. Light rolling gives a tight, needle-shaped leaf; heavier rolling gives a more twisted, broken leaf with a faster extraction.
Drying usually happens in two stages: a first firing to bring the moisture down to about a third, a rest period, then a second firing to bring it to the storage-safe level of around five percent.
Sorting by size and shape is the final step and is what makes the difference between grade one and grade three of the same tea. It is also where hand work still matters: a skilled sorter can pick out leaves that a sensor misses.
The four stages together take between four and eight hours from plucking to sealed bag. The time sounds short until you remember that the tea inside has been transformed from a living leaf into a shelf-stable product in the space of a single morning.
A premium lot may spend twenty to thirty minutes in rolling, two hours in firing one, an hour resting, and 90 minutes in firing two. A bulk lot compresses the same arc into half that time.
Sorting is where most of the visible grading happens. A grade-one Longjing might be 95 percent whole flat leaf with no yellow or broken pieces. A grade three tolerates ten to fifteen percent of either.