Tea Appreciation: Tencha

Tencha (碾茶) is the Japanese green tea that is ground into powdered tea called matcha.  The process to harvest and produce tencha and then to produce small quantities of matcha is very costly, so a large percentage of the "matcha" sold outside Japan is actually powdered sencha, which tends to be more astringent.

Growing
Tencha tea plants will typically receive three times more fertilizer than other tea plants.  In mid-April, 20-30 days before an early-to-mid-May harvest, tencha plants are shaded with tana, a framework covered with mesh cloth.  With 90% of the sunlight filtered out, the leaves work harder to grow, producing more chlorophyll, more amino acids like L-theanine, and fewer bitter tannins.  The results are sweeter and milder than unshaded teas like sencha.

Harvesting, Processing, and Evaluation
Typically, three leaves and a bud are plucked and the tencha will be harvested, processed, and stored within 24 hours.  The leaves are steamed and dried to become aracha (rough tea).  Then, the veins and stems are removed and the leaves are cut to a uniform size to become shiagecha (refined tea).  Unlike other teas, tencha is dried flat with no rolling.  Most green teas are rolled to break down the cell walls of the leaf, increasing oxidation and the release of enzymes responsible for the character of the tea.  Since tencha will be stored before being ground into matcha, there is no need to begin the oxidation process early.  Because matcha begins degrading soon after it is ground, tencha is used for evaluation and grading purposes.

Final Processing and Availability
Tencha can be produced from many different cultivars and varieties of tencha can be blended to produce qualities specific to a named or branded matcha.  Tea companies will store the tencha, sometimes giving it an additional drying, before grinding in small batches so the matcha will be fresh when it's ready for sale.  While all tencha can become matcha,  only higher grade tencha can be brewed with desirable results.  Due to scarcity, tencha can be difficult to find for sale, even in Japan.

Preparation
Tencha is prepared similar to gyokuro at a slightly lower temperature than sencha.  Heat water to 140°F/60°C-160°F/71°C and steep for 1-2 minutes before serving.  The leaves tend to float, so you may need to use something to push them down and extract their full flavor.  The results will be light and rich with umami with similarities to matcha in flavor and aroma.