Japanese Green Tea Harvesting and Processing
Tea leaves are formed in the uppermost shoots. This is where the young, tender new leaves and buds are formed. The top two leaves and the bud are prized both for their fullness of flavor and their ability to be twisted or rolled into a variety of shapes.
For high-grade sencha, harvesters pluck either the bud or the bud plus the youngest leaf. For good, to average tea, they pick the bud plus the top two leaves. For lower quality teas they pick the two top leaves, the lower leaf below them, plus parts of the twig.
After the leaves are picked they are immediately taken away for processing. Processing for green tea is markedly different than for black teas. To make black tea, the fresh leaf is withered by exposure to air and is broken and left to ferment after picking.
For green tea, the leaf is not fermented at all. It is steamed immediately after harvesting to stop the fermentation process. Sencha is dried after steaming and, when dry enough, rolled into a variety of shapes until it is completely dry.
About 75% of all tea harvested in Japan is graded as sencha
The quality of sencha is, however, highly variable. Quality depends on the tea's origin, the season, and leaf processing techniques that are used.
Only the youngest flush leaf is picked for gyokuro
Special cultivation techniques are employed to produce a tea that is famous for its rich flavor and pale lemon-green color. Gyokuro tea plants are grown in the shade for approximately three weeks before harvesting begins. Removing direct sunlight in this way reduces leaf photosynthesis which alters the proportions of flavonoids, amino acids, sugars, and other substances that provide tea aroma and taste.
For high-quality gyokuro, the leaves are (unlike sencha) aged for about 3 months. This aging blends and mellows the flavonoids and other organic compounds to produce a tea that is renowned for its smooth elegant taste.
Matcha is traditional powdered tea
Matcha differs from gyokuro in that the leaves are not rolled at all. After steaming, the leaves are thoroughly dried. This is tencha.
The tencha is then ground into a super fine powder, and that powder is what is known as matcha.
As green tea is unfermented, it contains much larger quantities of a group of powerful antioxidants called polyphenols which are chemically altered during the fermentation of black tea.