Tencha is the raw material for matcha — Camellia sinensis leaves grown under shade for 20-30 days before harvest, steamed to halt oxidation, then stripped of stems and veins. The shading forces the plant to produce extra chlorophyll and L-theanine, giving matcha its vivid green colour and umami flavour. Tencha is never rolled like other Japanese teas; it is dried flat and kept in leaf form until grinding.