Green tea and its famous powdered cousin, matcha, are everywhere. Brewed hot or iced, it is now even used in cosmetics... It is said to have antioxidant and anti-inflammatory properties, a lower caffeine content than black tea and a color that evokes nature and purity. But is it really as virtuous as claimed? We went to Jeju, South Korea, to discover its secrets and myths, and to debunk a few marketing exaggerations.