Aged tea: The evolution of taste over time

お茶の熟成：時が育てるお茶の味

In the most parts of Japan, May marks the first harvest season of Japanese tea of the year. During this month, the shelves of all tea shops are filled with the new teas (新茶 sincha), celebrating the beginning of this new season. 

Have you wonder what makes the difference between the new and old harvests of Japanese tea?

Like wine and whiskey, Japanese tea is a drink that evolves its flavors over time. At the favorable conditions, Japanese tea can be aged to create richer, deeper flavors. In the current Japan, the taste of new teas are much more appreciated. However, the tradition of aging Japanese tea is still remaining in matcha (抹茶) in the Way of Tea (茶道 sado: the traditional arts of Japanese tea ceremony).

Traditionally, the newly made tencha (碾茶, half-processed tea leaves before milling to become matcha) is first stored in a special sealed bottles called "茶壷 chatsubo" to rest and age for a few months. During the process of aging, these chatsubo are carefully sealed and placed at the cooler place to avoid the degradation of tea leaves by oxigen, humidity and high temperature. Before the time of controlled storage technologies, the teas were typically stored in the cold caves in the high mountains. Every November on the day of Ritto (立冬, meaning the beginning of winter) is the first day of opening the chatsubo, milling the tencha and making the first cup of matcha.

By proper aging, the tastes of any kinds of tea become deeper and rounder, meaning that the flavors are more balanced compared to non-aged equivalents. For example, Japanese sencha (煎茶, steemed green tea) has characteristic green aroma with sometimes even harsh astringency when newly produced. However, after aging, the greenness and astringency are no longer standing out and instead more complex, richer flavors linger on the tongue. I personally associate the green flavors of new teas is like the taste of spring in Japan, and the round, mature flavors of old teas with deepening winter in Japan.

It is not about which is the best. Like humans, there are different unique charms of new teas and old teas. Some green flavors and astringency can be refreshing in summer. The round flavors can be more calming and relaxing. 

Once harvested, all Japanese tea become older day by day. But the aging opens a new possibility for us to make this process into a whole experience to enjoy the taste of time.