I hope after reading this article, you will have a comprehensive understanding about green tea, and be able to easily identify and purchase some high quality leaves. Let’s begin with the processing of green tea. This might seem a little technical, but understanding how green tea is made can help us to both identify quality and understand how to preserve this quality for a longer time than you might expect.
Withering
In general, there are 4 steps for processing green tea. Following picking, tea leaves are ‘withered’, a process where tea farmers lay a thin layer of leaves in the withering room undisturbed, allowing them to dehydrate by around 30 percent. This step is the first key element to a successful green tea, the reason being, when the leaves are withering, they turn soft and flexible, and chemicals in the leaves begin to alter. The aroma begins to be released. Amino acids, carbohydrates, pectin all increase, which causes the flavour to become more fresh and brisk, sweeter and richer. Catechin decreases, making the tea less astringent. So a good withering process establishes a good foundation for the remaining steps. Unfortunately, a trend towards commercialism has driven many industries to become more and more fast-paced and money-driven, and this is true too of the tea industry. It seems we as individuals can do nothing about this, but our demands for superior tea can in fact encourage tea farmers and producers to continue producing tea using the old ways which have gradually been disappearing in the modern world. Drink less, drink better.
Sha Qing – to “halt oxidation”
After a few hours withering, "杀青"(pronounced "sha qing") is the following step, meaning to “halt oxidation". The enzymes in the leaves are in charge of the oxidation, when the temperature heats up to 30-40℃, they reach their most active point; by around 80℃, however, they become inactive. There a few ways to "halt oxidation", like wok-firing, steaming, baking, and sunning. Lets take wok-firing as an example since it’s the most widely-used way in China. When the leaves have been put in a heated wok, the temperature of the leaves won’t be heated over 80℃ immediately, but rather rises gradually. if the temperature rises too quickly, the leaves will burn, but if it rises too slowly, the leaves will become overly oxidized. When the temperature is kept under 80℃, the enzymes continue to be active, resulting in a mixture of red leaves in the green leaves, affecting the overall quality of the batch. Evidently, controlling temperature is very important to the quality of green tea.
Rolling and Shaping
This is to break the cells of the leaves (to a certain percentage depending on different types of green teas) so we could brew more chemicals out of tea. Leaves are often shaped according to local tradition, with some being balled up, others being rolled into long curled-up tubes, others dried completely flat. While this shaping serves a chemical purpose, the final shape is ultimately determined by received tradition and can sometimes serve as a signature for a particular type of tea leaf.
Drying
Proper drying could guarantee leaves stay stable for a longer period. If you have ever come across a situation where tea that tastes fresh and smells floral when bought, smells stale and unpleasant after only 2-3 months, this is most likely because the moisture content of the leaves itself was too high when made. The moisture content should be 3%-5% for green tea, this certain amount of water in the leaves could protect it from oxidization and deterioration while being stored. This explains why we should also keep our tea in a dry and cool place at home.
Some people say that green tea should be consumed within one year or even sooner, but this is only partially correct. With the right processing methods and storage conditions, green tea can last much longer. If you are confident with what you are purchasing, there is no rush to drink it quickly.
All photos above show the processing of Taiping Houkui, courtesy of Tingliu TeaStudio.
-the end-
written by Fang yaoyao
Comments