Shaded tea is simply tea that is covered for a short period before harvest. Shading tea is a technique that was developed in Japan in the 15th century, originally with the aim to protect the tea leaves from early Spring frosts. However, farmers quickly discovered that shading tea gave some unexpected, and wonderful benefits.
Today, there are 3 main methods for shading tea. Direct shading (“jikagake”) is done with a ventilated synthetic black tarp that’s laid directly on top of the tea plants. This method is often used on tea fields in hilly areas. Shelf-style shading (“tanagake”) is a method where ventilated synthetic black tarps are placed on a raised framework above the tea plants, which allows more circulation of air since the tarp is not resting on the tea plants. This style is more common in flat tea fields. Lastly, the most traditional and labor-intensive method is shelf-style shading with a covering of natural straw or reeds (“honzu”), which can allow for a longer shading period of the tea plant as it’s easier on the plant.
All matcha is shaded for a few weeks before harvest – if the tea leaves have not been shaded prior to harvest, then it isn’t real matcha. Shading is a key step in matcha production that’s critical to give matcha it’s rich umami taste. When the tea leaves are shaded, something special happens in the plant that helps transform the flavor profile of the finished tea. L-theanine is an amino acid that is only found in the tea plant (camellia sinensis) and a few mushroom varieties. L-theanine develops in the roots of the plant and is transported out into the leaves, where it starts to get broken down by sunlight and transformed into catechins. L-theanine on its own is responsible for a sweet taste profile, while catechins have more of a bitter taste. However, when the tea leaves are shaded from the sun, this helps stop the L-theanine from breaking down into catechins. This results in the tea leaves retaining more L-theanine that give natural sweetness and umami, and less bitterness from lower conversion to catechins.
When the tea leaves are shaded, something special happens in the plant that helps transform the flavor profile of the finished tea.
Several types of Japanese green teas are also shaded before harvest. Kabusecha (literally “hidden tea”), gyokuro (“jewel dew”), and even some sencha varieties. The main difference is the length of time that the teas are shaded. Kabusecha is typically shaded around 2 weeks, gyokuro is shaded for around 3 weeks, and matcha (called ‘tencha’ before it’s ground into a fine powder) is shaded for 3 or more weeks. Longer periods of shading typically yield higher L-theanine content and a stronger umami flavor profile. But the longer the shading period, the harder it is on the tea plant as it’s being deprived of sunlight. Therefore, it takes great skill from the farmer to extend the shading period while maintaining the integrity of the plant.
Besides giving the tea a more delicious taste, L-theanine is also known for its calming and relaxing effect on the brain. Tea leaves also contain caffeine that promotes energy and alertness. Rather than the effects of caffeine and L-theanine canceling each other out, they have a synergistic effect. The L-theanine smooths out the effects of caffeine, so rather than getting a typical quick jolt of energy followed by a crash from caffeine by itself, you get a gentler onset of energy and alertness which lasts longer and tapers off without the crash. It also curbs the typical jitters one can get from caffeine, and promotes better cognitive function with calm, focused, and sustained energy. Tea leaves are the only naturally occurring combination of caffeine and L-theanine, and it’s this combination that creates a positive effect on mood, focus, and energy when drinking tea made with leaves from the tea plant. Because shading results in a higher content of L-theanine in the leaves, shaded teas make a great choice for those looking for more balanced, focused, and sustained energy.