Translated from Japanese, umami means “pleasant savory taste.” Besides bitter, salty, sweet, and sour, ummai is the fifth taste. L-Theanine contains both umami and sweet components according to scientists. A study of taste in Matcha revealed that L-Theanine acts, along with other substances, as an enhancing agent on the glutamates in tea to create the umami flavor. However, the way Matcha is made is significantly different from Gyokuro. Interestingly, it appears that L Theanine is created in the tea plant’s roots and distributed through the the plant’s vascular system into its leaves where it transforms from L-Theanine to catechins through photosynthesis.
Because photosythesis is just starting in the spring, L-Theanine is strongest in that it has not had time to convert to catechins. This would obviously also apply to shade grown Japanese teas and teas that are composed of only buds.
Most people who drink Gyokuro prefer to steep 2 grams per 6 ounces of 160 degree water for 1-2 minutes in order to get the umami flavor. However, some aficionados prefer steeping using 3 times as much tea to water at a lower temperature.
By Certified Tea Master Chas Kroll