Honzu
Definition
The traditional Japanese shading method for gyokuro and tencha that uses layered rice straw over reed screens. It produces deeper umami, sweeter aroma, and richer green color than modern synthetic shading.
Why it matters
Honzu (or honzu shitate) shading is a labor-intensive technique used in the highest grades of Uji gyokuro and tencha. Tea bushes are first covered with reed or bamboo screens (yoshizu), then layered with rice straw (komo), progressively reducing sunlight to roughly 10 percent or less over a two to three week period before harvest. Under shade, the tea plant slows photosynthesis but continues to produce amino acids, especially L-theanine, while catechin development is suppressed. The result is a leaf rich in umami and sweetness, with reduced bitterness and astringency, and a deep emerald color. The straw covering also moderates temperature and humidity around the bush, contributing to the so-called ooika or "covered scent" associated with the finest gyokuro. Most modern shaded teas use black synthetic netting (kanreisha), which is far cheaper but lacks the temperature buffering and gradual light reduction of honzu. Honzu-shaded teas are rare, expensive, and considered the pinnacle of Japanese cultivation craft.