Introduction
Green tea, known in Chinese as lǜchá (绿茶) and in Japanese as ryokucha (緑茶), is the most widely consumed unfermented tea category worldwide. Unlike black or oolong teas, green tea undergoes minimal oxidation, preserving the fresh, vegetal character of the leaf and a high concentration of polyphenolic compounds, especially catechins such as epigallocatechin‑3‑gallate (EGCG). This FAQ‑style compilation gathers the most common questions from tea enthusiasts, beginners, and health‑conscious consumers, providing evidence‑based answers rooted in historical texts, classic tea manuals, and modern scientific research. Whether you are curious about brewing techniques, health implications, storage practices, or cultural background, the following sections offer detailed, practical guidance to deepen your understanding and appreciation of this timeless beverage.
What Is Green Tea?
Green tea is defined by its processing method: after harvesting, the leaves are quickly heated to halt enzymatic oxidation, a step traditionally called fixation or kill‑green (shāqīng, 殺青). Because oxidation is prevented, the leaf retains its green color and a biochemical profile rich in chlorophyll, amino acids (notably L‑theanine), vitamins (C, B2, E), minerals, and polyphenols. The unfermented nature (0 % oxidation) distinguishes green tea from partially fermented oolong (≈10‑80 %) and fully fermented black tea (≈100 %). Historical sources such as Lu Yu’s Chájīng (茶經, The Classic of Tea, 8th century) describe the earliest green tea processing as “steaming the leaves to preserve their natural hue,” a technique still used in many Japanese varieties (e.g., sencha, gyokuro). In China, pan‑firing (chāo qīng, 炒青) became dominant during the Tang and Song dynasties, giving rise to the characteristic nutty, toasty notes found in Longjing (Dragon Well) and Biluochun teas.
How Green Tea Is Produced
Although regional variations exist, the core steps of green tea manufacture are