「昔 Mukashi」& 「白 Shiro」
Names of varieties of tea often end in either「昔 Mukashi」or 「白 Shiro」. This is curious as they seem to have no connection to the tea they name - ‘mukashi’ means ‘past’ and ‘shiro’ means ‘white’. Nowadays these words distinguish whether the tea is koicha (thick tea) grade or usucha (thin tea) grade tea. However, 「白 Shiro」is a recent addition in the tea-naming vocabulary and originally only「昔 Mukashi」was used. Tea that has the name 「昔 Mukashi」is of the highest quality, and is tea of the first harvest of the season. One explanation of the origin of the 「昔 Mukashi」naming convention is that the first harvest is conducted on March 20 on the lunar calendar (start of May on the current solar calendar) and this date is the origin of the name 「昔 Mukashi」as the character for ‘20’ is 廿 and ‘day’ is 日. Put them together and they resemble the character 昔.
Another more widely accepted explanation is that the first harvest was conducted in a 21 day period around the ‘88th night’ (八十八夜 hachi jyu hachi ya). The 88th night is the 88th night after the first day of spring. This day is May 2 on the current calendar (May 1 on leap years). The 88th night is said to be the best time to pick tea, and tea drunk on this day is said to protect you from sickness for the year. Tea picked in the 21 day period around the 88th night is given the name 「昔 Mukashi」as the number 21 is written 廿一 and day 日. Put them together and you get a character that resembers the character 昔.
「白 Shiro」in tea names appears during the reign of the 3rd generation Tokugawa shogun, Tokugawa Iemitsu (1623 - 1651). The origin comes from the requests of daimyo teaists to tea producers in Uji to produce ‘tea that is white’. The precise meaning of this expression of ‘white’ used at the time is unclear. There are records of Oribe preferring 青茶 aocha ‘green’ tea, and Enshu preferring 白茶 shirocha ‘white’ tea. It is thought what they referred to by these names were differences in the process of steaming the tea leaves after harvest resulting in different colours in the tea. A widely accepted explanation of 白 among producers is that the first harvest young leaves have fine white hairs on them and tea with such high quality leaves produced a light, airy tea of slighty white appearance.