The tea bush is known to produce amino acids during tea cultivation. These are transferred to the fresh buds for their initial development. When the sunlight reaches those buds, photosynthesis occurs and causes these amino acids to change into catechin. While amino acids are chemical components that are responsible for a sweet, umami flavor, catechin components imbue the final product with a rather bitter taste.
The preference for a sweeter taste over bitterness is almost as old as tea’s history in Japan itself. One of the first places where tea in Japan was intentionally cultivated was at Kōzan-ji temple on Mt. Togano’o situated to the north-west of Kyoto. The natural conditions and ecology in the precincts of Kōzan-ji were considerably well suited for the cultivation of tea. It favorably supported the luxuriant growth of tea bushes in the area. In addition, the tea produced in this region rapidly became known as a product with a genuine flavor and strong aroma, distinguishing it from tea produced in other areas. Later on, tea consumers began to refer to the tea produced in Togano’o as ‘real tea’, opposing to the tea produced in other areas, which was referred to as ‘non-genuine tea’. Successively, blind-tasting games in which players distinguished whether a tea was ‘genuine’ or not developed rapidly.
Expanding the cultivation of Japanese tea
When the demand for tea grew, it was especially among tea producers in the town of Uji, south of Kyoto, that people began questioning what made the difference between ‘real tea’ from Togano’o and other non-genuine products. Soon they came to the conclusion that since the tea from Togano’o was produced in the mountains in locations that were overgrown with tall trees (as opposed to the level and open surfaces in other areas), tea bushes in this region had received less sunlight during their growth. Linking this environmental trait immediately to the outcome of the flavor of the tea, manufacturers in the Uji precincts developed methods to imitate the natural conditions of Togano’o. This resulted in an application that has laid the groundwork for the shading practices that are employed today for the cultivation of those rather lush, sweet brands of tea that are especially indicative of Kyoto’s tea.
By shading the tea bushes, the occurrence of photosynthesis is suppressed, preventing amino acids in the tea leaf to convert into catechin. This is, as explained above, the main purpose of shading practices. However, as a side effect of cutting sunlight, the tea leaf inevitably becomes much thinner, softer and darker in color. Since the tea bushes receive less sunlight than it desires, the leaf tends to spread as wide as possible in search for faint beams of sunlight. Accordingly, the tea leaf becomes thinner as it stretches, and although the leaf may grow quite large, it doesn’t easily grow coarse. Luckily these are considered traits that are favorable for the manufacturing of tea varieties such as matcha and gyokuro, for which deep colored, tender and soft leaves are considered desirable.
Intentionally shading tea bushes
Shading methods are common practice today (and continue to become more popular even for varieties of tea that traditionally weren’t produced from shaded leaf). And, depending on the desired outcome, a variety of applications are commonly employed. It is safe to say that most contemporary methods have derived from the traditional straw-covering method of shading, and that they are in essence a simplification and means to reduce the labor intensity of the shading process for the producer. Therefore, subjected to the financial capacity of the manufacturer and the intended product to be created, a more elaborate or rather simplified method is selected.
How to understand tea cultivation?
Later posts on this blog will contain more detailed explanations of various cultivating and manufacturing methods. But before I say anything else, I must first bring to attention a point of caution that I feel is of ultimate importance when seeking an understanding of the subject.
It goes without question that the measurements and approximations used in the explanations of various methods are merely an indication of what has come to be known as the average practice. In reality the process is much more complex, relying to a greater extent on the producer’s understanding of the environment’s natural conditions and how his tea bushes react to it. Because tea is an agricultural product, its growth depends mainly on atmospheric circumstances, in effect demanding from its grower a similar flexibility.
By means of illustration, I wish to describe an irregularity that affected the tea harvest in Spring 2018. Although the yearly tea cycle is said to commence in March-April with getting the tea bushes ready for cultivation and shading, this year the temperatures drove up to above 20 degrees Celsius for a brief period in February, and then quickly dropped again. This didn’t only motivate the tea bushes to awake from their hibernation and start producing young buds, it also caused them to become vulnerable to frost damage due to the returning cold after this irregularly warm period. In this particular case manufacturers were forced to begin tending to their tea bushes, by applying shades to protect them from frostbite, and guiding them to a successful harvest in March.
When due to some unforeseen reason the tea bushes develop faster or more slowly than was initially estimated, the producer too has to adjust his shading and harvesting schedules accordingly. We mustn’t forget that tea is produced at the rhythm of the plant, and not at our own pace. Therefore, when I explain cultivation and manufacturing methods, I want you to remain aware of the fact that all indicators of timing, amounts, heats, etc. are but an average number taken from common practices. And that the reality is much more complex. It demands of the manufacturer an interdependence with environmental circumstances; characteristics of the bush or the tea that is being produced; the region where the tea is being manufactured; and all other possible natural factors that play a role in the growth and manufacturing of tea.