I heard that kukicha contains more theïne than Sencha? But I Always thought that theïne was stored in the polyfenol of the leaves (green) and not in the twigs.
Since I work in a coffee and tea shop, my collegues and I have a lot of discussions about theïne. Maybe you can tell us more about theïne. Does the terroir and time of harvest have any influence?
Hope to hear from you.
Dear Raymond, thank you for the questions. And it is a fairly difficult one to answer.
Research suggests that theanine is found in all parts of a tea plant, but may be more so at the young shoots. Following this, leaf teas, made from young shoots, should have more theanine than stem teas. However, there are a few other factors that come into play. It is known that there is a link between the amount of nitrogen (common in plant fertilizers) and theanine ; as well as that theanine is converted to catechin through photosynthesis (that can be slowed down with shading the plants). Which means that the amount of fertilizer used as well as the length of shading period will have great a influence in the amount of theanine found in a tea plant.
Now, Kukicha is usually made by separating the stems from higher grade teas such as Tencha, Gyokuro, that are often fertilized more and shade longer. Sencha is also a broad category: it can be grown in a field open to the sun or shaded, fertilized more (in spring) or less (in later seasons). So to answer the question precisely, lab tests would probably be necessary.