In this Matcha Education blog post we will be discussing the positive effects the shade growing process has on tea plants used for Matcha production and why specifically this process is beneficial to the quality, nutrition, and flavor of the finished tea.
Before beginning, it is important to note that there is another variety of Japanese green tea called Gyokuro that is also shade grown and is commonly confused to be related to Matcha. While some of the points listed below do apply to Gyokuro in terms of the finished tea’s flavor, Matcha and Gyokuro are quite different in the steps taken to make them. Once the leaves for each of these teas are harvested, they are refined and treated differently depending on what they are to become. Matcha is never made from Gyokuro; it is always made from Tencha - the formal name for shade grown, refined tea leaves.
The tea plants whose leaves are destined to become Matcha are gradually shaded over the course of the month before the tea harvest. A layer of black burlap-like material is draped over a framework erected around the fields one layer at a time each week with subsequent layers being placed on top of the previous ones. This whole process lasts 3-4 weeks. Once the last cover is laid in place, 90% of the sunlight going to the tea field is blocked and even if you were standing in one in the middle of the day, it would seem like it was dusk.
Under the shade covering, the leaves of the plants spread to try and absorb as much light as possible so as to compensate for the decrease in sunlight needed for photosynthesis. As the leaves widen they also get thinner and more tender. This benefits the grinding step of Matcha production as thinner, wider leaves are more easily ground down into a fine powder. Shade growing also boosts the chlorophyll content of the leaves, leading to them having a much more vibrant jade green color. With finished Matcha, the vibrant jade green color is an indication of proper shade growing.
It is not just the color of Matcha that is affected by the shade growing process; the taste and smell of the tea are also affected. Direct sunlight breaks down the amino acids in the leaves, converting them to catechins, making the tea more astringent. Shade grown tea plants maintain their amino acid content, resulting in leaves with a more natural sweetness. This is one of the main reasons high quality Matchas have a naturally sweet flavor profile (this taste is often called umami flavor) with little to no bitterness. Non-shaded, open air grown green teas that are used to make Sencha powders or imitation Matchas do not maintain their amino acid content and as a result are far more astringent when consumed in the whole leaf context. In addition to flavor, amino acids give the tea it’s sweet smell, often referred to as a “sweet, vegetal aroma.”
Finally, the nutritional content of the tea is also positively affected by the shade growing process. The key amino acid that is preserved in Matcha is L-Theanine. Many studies have been conducted around this amino acid relating specifically to it playing a role in helping in cognitive function, increasing the mind’s ability to focus, helping relieve stress, and assist in the gradual absorption of caffeine by the body for longer energy with no crash. It is due to these nutritional and energetic properties that Matcha is still consumed in modern Japan by Zen Buddhist monks to help them focus and keep a “calm alert state” during meditation.