All types of green tea come from the same plant— Camellia sinensis.
The quality, composition, and flavor of tea depend on the location, soil, and elevation at which the plant grows, the harvesting time, and the leaf-processing techniques. Tea processing includes different methods and degrees of leaf oxidation, oxidation prevention, shaping, and drying.
The highest-quality teas come from the first spring harvest , when the plant has preserved nutrients through the winter and the leaves contain them in their highest concentrations. One of the best-known spring teas, very rich in vitamins and amino acids and very low in catechins and theine, is Spring Shincha. Gyokuro Okabe also belongs to the highest grade. It is shaded for several weeks before harvest to increase its theine content while giving it an exceptionally mild and sweet flavor.
Every subsequent harvest from the same plant falls into a different category from the first harvest, which produces the highest-quality tea. In Japan, harvesting begins in late April. A bud and several leaves are picked from each plant. The first harvest takes place in April and May, the second in June, the third in July, and the final harvest in September. The lowest-quality and least expensive tea is produced by harvesting and processing large mature leaves, which significantly affects both flavor and quality.
Green tea is processed in different ways, and its preparation also depends on the type of tea. Some teas are steeped for only a little more than half a minute at 50–60°C, while other green teas are steeped for several minutes at 90–100°C. To obtain the maximum benefits and healthy compounds from tea, it is important to follow the preparation instructions.
Another characteristic of high-quality teas is that the same leaves should be suitable for three to six infusions. Chinese and Japanese tea drinkers place the leaves in clay, porcelain, or glass teapots, or in a traditional gaiwan, and use the same leaves for as many as ten infusions. Depending on the type of tea, subsequent infusions may produce a weaker or stronger flavor; for some teas, the second or third infusion is the best. Each cup will still contain nutrients from the leaves.
