Sometimes one can hear the expression umami used by tea enthusiasts. This term is used especially in conjunction with high-quality Japanese and Chinese green teas. Although umami was already discovered in 1907 by Japanese scientists Kikunae Ikeda it’s quietly unknown to a huge part of the population. In addition to sweet, sour, bitter and salty umami is another flavor and is therefore also known as the fifth taste. Umami means a savory or meaty taste and serves to detect protein-containing foods.
How umami gets into tea?
What gives umami taste in green tea is the amino acid L-theanine. This amino acid is formed in the leaves of Camellia sinensis. But, during growth a large amount of L-theanine is transformed by sunlight into catechins and other substances. Umami can therefore only be found in young tea leaves or leaves that are protected from direct sunlight. A good example are teas like Lu Shan Yun Wu (cloud and mist tea) and other teas from foggy regions. Japanese tea growers however, have developed a special technique: Kabuse. High quality green teas such as Tencha, Gyokuro or Kabusecha are artificially shaded and achieve the same effect as fog and clouds.
Why is there no umami in black tea?
In black tea and, to a lesser extent, in oolong, yellow and white tea the L-theanines are degraded or transformed by oxidation. Since at the same time bitter substances such as catechins are also degraded those teas are not more astringent than green tea but, on the contrary, even more wholesome.
How to get the umami experiance
As mentioned before young leaves with little exposure to solar radiation are subjected to a high proportion of L-theanin. Typically, these are green teas from the first harvest in spring when the sun is still very weak. These teas are also known as First Flush or Shincha. Also highland teas such as Lu Shan Yun Wu or Meng Ding Gan Lu, which are protected by a thick layer of fog from solar radiation contain large amounts of L-theanine. Another category are teas grown in shadow. These includes particular Gyokuro, Kabusecha, Tencha and the Matcha (which is made from Tencha). A shaded First Flush tea such as a Shincha Gyokuro should have the highest L-theanine content. In order to get maximum umami taste these teas should be brewed around 50°C warm water. At higher temperatures more bitter substances are dissolved and thus diminish the umami experience.
Korean Woojeon green tea is characterized by a special umami flavor and is favorable in price. Through the combination of steaming and roasting, this tea combines features of Japanese and Chinese green tea.