While the episode in the previous article allows us an insight in the advent of tea in Japan, it also introduces some of the most important factors that play a decisive role in the cultivation of tea bushes for the manufacturing of matcha. In this article, I will look to define the traditional aspects of cultivating tea bushes for matcha, as well as to introduce how these methods have been altered to meet contemporary standards.
But first, I feel that it is necessary to explain the difference between ‘matcha’ [抹茶] and ‘tencha’ [碾茶]. The tea we consume in its powdered form is what is called ‘matcha’, but this term only refers to the tea as the final product. In the final stage of matcha production, the processed and dried tea leaf is ground into powder using a stone mortar. After the grinding, we speak of ‘matcha’. Everything that happens before this final grinding process is referred to as the production of ‘tencha’. Therefore, in the course of explaining how tea is grown and processed for the production of matcha, I will be referring to this product as ‘tencha’, as this is what the raw material for matcha is called most often.
During winter, the tea bush pauses its growth in order to cope with the cold winter season. From October until the beginning of spring in February, the tea bush accumulates nutrition from the soil in its roots in order to withstand the frost. When the days grow warmer, and spring announces itself, the tea bush awakens from its hibernation. The nutrition it has gathered in its foundation is now gradually transferred to the newly sprouting buds, which will become the source of Japan’s most delicious tea. In comparison to later seasons, it is the spring harvest that is considered highest in flavor and nutritional value. The winter season has allowed the bush to garner minerals and nutrition for an extensive period of time, and it is only through this that the tea can naturally enhance its flavor. Therefore, other seasons are bound to be considered inferior in terms of final produce.
Around mid April, reed screens are rolled out on the wooden structure above the tea bushes. This initially limits the sunlight reaching the plants somewhere between 60 and 75%. Recent research has discovered that it is through photosynthesis that amino acids such as theanine, which are responsible for a sweet flavor, transform into antioxidants such as catechins, components that are responsible for bitterness. For a more delicious matcha, it is considered beneficiary to limit the amount of sunlight reaching the leaf, reducing photosynthesis to allow for a sweeter, less bitter end result.
Approximately 10 days after having put the reed screens in place, another layer of straw is spread out on top. This limits the amount of sunlight reaching inside the construction further to over 90%, almost leaving the plants completely in the dark. This scarcity of sunlight, forces the leaf to reach out further in order to catch the natural light needed for their growth. This effort makes them grow wider, but also thinner, and renders them softer and more brightly green in appearance.
Nowadays many farms have replaced the traditional wooden structure with an aluminum frame. Because the wood may corrode when left outside for too long, it has to be carefully stored and tended to. Therefore, after each harvest season, it has to be taken apart and carried to a dedicated storehouse. With an aluminum frame, this effort can be omitted, as it can be left outside during all seasons. In addition, the reed screens and straw covering too have been replaced with black covering sheets of cheesecloth typically manufactured from polyethylene. These covers are installed in two layers over the tea bushes that can be used in a similar way to adjust the intensity of the light shutout.