Shading

Definition

Shading (被覆, hifuku) means blocking sunlight from tea bushes in the weeks before the spring harvest. In Japan, farmers cover rows with black synthetic cloth or traditional straw (honzu) and reed screens, either draped directly on the bushes (jikagise) or on a frame above them (tana). Shade typically starts around 70 percent and is often increased toward 90 percent or more as harvest approaches. Shade changes leaf chemistry. In sunlight, tea plants convert L-theanine, made in the roots and moved to the young leaves, into catechins. Under shade, more theanine stays in the leaf and fewer catechins form, so the tea tastes sweeter, more savory and less astringent. Leaves also make more chlorophyll to capture scarce light, turning a deep blue-green. Some caffeine increase is also reported in shaded leaf. Shade duration defines the tea. Kabusecha is shaded roughly one to two weeks, giving a cup between sencha and gyokuro. Gyokuro is shaded about three weeks or more, usually under a frame. Tencha, the leaf ground into matcha, is shaded about three to four weeks. Chinese teas are rarely shaded intensively, though some producers now copy the method.