Blog 16: The Evolution of Tea Leaf Fragrance During Tea-making (Part I)

Updated: Oct 19, 2018

In the last blog, I have briefly introduced the changes in tea leaf fragrances in Wu-Yi oolong tea-making. Today, let’s explore more on this topic.


The smell of tea leaves plays a critical part in determining the progress of tea-making. During the whole tea-making process, a leaf’s smell would change multiple times. Although all fresh leaves start with variables in their raw scents. All processed leaves would have the same fragrances.


Since we are talking about fresh tea leaves, it is worth pointing out that there are two kinds of tea plants, tea bushes and tea trees. No matter from what kind of tea plants, tea leaves do not carry a particular special scent other than the ordinary herbal aroma from common trees or grasses.


However, after the harvest, the fragrance of tea leaves would start changing. The first fragrance is the grassy smell. This is a result of green plants releasing “green leaf volatiles”, or GLVs, in emergency. This grassy smell usually don’t last long. The smell would soon gradually turn to the raw-herbal smell or a tired-grassy scent (like the not-so-fresh smell of a recently mowed grass field) under the sun or in an open-air environment.

Fresh Leaves in Sun Drying

During the sun drying process, the first step after the harvest, the raw-herbal smell would enhance and die out while leaves being flipped and turned. Then, fresh tea leaves would develop a refreshing leafy smell due to the light withering. After the sun drying, fresh leaves would be moved to a relatively closed environment. In this environment, leaves would be shaken a few times on a sifter and then placed on the rack. Each sifter would carry about 1kg/2.2Lbs of fresh leaves. While resting on the rack, leaves would continue to wither and slowly lose water. If you touch the leaves now, you would feel that leaves are wet, cool and stiff. Together, they release a mixed fragrance of refreshing and raw-herbal smell.


After resting slightly more than an hour, fresh leaves would become silky smooth like a baby’s skin. While leaves still emit refreshing leafy fragrance at this stage, they would be much cooler in temperature. From here, the shaking process starts. The first shaking is usually a light one. A tea master would shake the sifter to make all leaves on the sifter go clockwise. Leaves rotate in the mid air and crash into each other. The correct shaking can break a leaf’s edge while keeping the leaf’s integrity. Cells on the broken edge release organic acid that would oxidate and eventually become the aroma component. This is why an experienced tea master would bend down and sniff the leaves during the shaking. The first shaking is normally less than 10 times. The purpose of the first shaking is to wake up those soft and sloppy leaves. After the shaking, the ideal smell is a humid sweet fragrance. If a tea master does not smell this, he would shake the leaves again until the fragrance finally shows up.

Mr. Xue Sniffing Fresh Leaves During Tea-making

Once the first shaking is done, the tea master needs to re-gather all the leaves to the center of the sifter and place the sifter on the rack to let the leaves rest again. At that moment, the room is full of a strong, expanding, refreshing and sweet fragrance. The changes in a leaf’s fragrance mark the first crucial milestone in Wu-Yi oolong tea-making. (We will continue our journey in the fragrance change during the tea-making in part two.)


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Correction: In the previous version of this blog, I mistakenly stated that the first shaking is less than 15 times in paragraph six. The correct number should be less than 10 times.