Updated: Oct 19, 2018
As a tea category, oolong tea is always a little more difficult for people to understand. Unlike green tea or black tea, oolong tea products are usually classified into many sub-categories. For example, the most notable oolong tea sub-categories are Wu-Yi oolong rock tea and Tie Guan Yin. In our previous tea blog, we’ve explored that it is different tea plants that make one oolong tea different from another oolong tea. Today, we will discuss what makes oolong tea different from green tea and black tea.
The key difference among these 3 types of teas is the level of fermentation. Green tea is not fermented, and black tea is fully fermented. Oolong tea, however, is half-fermented. To achieve the state of half-fermentation, there are more procedures in the making of oolong tea. Among all techniques and steps involved, shaking (or shaking fresh green leaves, Chinese: 摇青) is the unique process that only appears in oolong tea-making.
Shaking is the technique that makes oolong tea special. The shaking process is the second step in oolong tea-making. It happens after the drying process. The first purpose of the shaking is to start the fermentation by letting fresh green leaves collide with each other and abrade the edge of the leaves. The ultimate purpose of the shaking is to transfer all water and nutrients from the stem into the leave. Fresh leaves are strong and firm because they are full of water. After shaking, the leaves would soften because water is lost through the broken leaf edge. When this happens, an experienced tea master would stop the shaking and let leaves rest. After a while, leaves would become firm again because the stem resupplies the water. The shaking would repeat multiple times. Leaves become more and more aromatic during this cycle of losing water and regaining water. The most distinct feeling after the shaking process is that the leave still has weight because it regains all lost water from the stem, but the stem is virtually weightless. Our tea master Mr. Xue also calls this repeating process “dying and reborn”. When losing water, leaves look withered as if leaves are dead, but after resting a while, leaves would become firm and young again as if all leaves are reborn. The final tea product with good shaking can last longer and endure more infusions.
Traditionally, the shaking process is done by hand. A tea master would hold a large, flat and round bamboo sifter. The sifter would carry a couple pounds of fresh leaves. When the tea master starts the shaking, all leaves are actually rotating in mid-air instead of simply moving left and right. A not experienced tea maker often make the mistake by shaking the sifter left and right, this would put all leaves in a line and eventually push some leaves off the sifter. One full shaking process has more than a thousand times of shaking. This requires the tea master to have a great strength and control over the sifter to perform a stable shaking. Nowadays, not every tea maker can do a full shaking, and even fewer tea makers can actually perform a perfect shaking that releases the full potential of the fresh green leaves.
In modern times, roller machine shaking is a popular way among most tea makers. Machine shaking can shake over 400 pounds of tea in a run, and it can shake at a strength that few tea masters can reach. But machine shaking also has its drawbacks. First, in a roller, leaves are unavoidably overlapping each other. This would release an unwanted wet smell. Second, all leaves need to avoid getting in contact with the heat duct in the machine. This requires the tea makers to be extra carefully when turning leaves during the machine shaking process. If even one leaf touches the heat duct, the result would be devastating. Once touching the heat duct, the leaf would turn red and release a rotting smell. This rotting smell would spread like cancer, and eventually the whole load of leaves would be wasted.
I hope the video and the picture above can help my fellow tea lovers have a better understanding of what the shaking process looks like. Of course, we’ve only skimmed the surface of this quite complex process. There are a lot more we should discuss. For example, the room temperature during the shaking, the weather required for handcrafted shaking, and so on. We will have a more detailed discussion on this topic as we travel farther into the realm of tea-making.
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