Inside one of Tokyo's last two barley tea factories, where mugicha gets its flavor

Ogawa Sangyo, one of only two barley tea (mugicha) producers with a plant in Tokyo, opened its Edogawa Ward factory to explain how the summer staple is actually made. Despite the name, mugicha contains no tea leaves at all — it is an infusion brewed entirely from roasted barley. The company sources its grain domestically, mainly from Ibaraki, Tochigi, and Toyama, and blends two barley strains for a fuller flavor. A shrinking pool of Japanese barley growers has driven up costs, but the firm remains committed to local sourcing.

The production hinges on a two-stage, direct-fire roast rather than the cheaper convection method most mass producers use. Grains are roasted alongside sand, which spreads infrared heat evenly to the core without scorching the surface — the same trick used for traditional roasted sweet potatoes. A first pass runs one minute at 250°C (yielding a fragrant, popcorn-like grain), followed by a second minute at 180°C, leaving the barley darker and plumper. Those twice-roasted grains, not tea leaves, are what get brewed.

Packaging is also two-stage: a machine bundles grain into tea bags at 50 per minute, then workers box them by hand. The factory offers both rectangular bags (easier to store) and triangular ones (better flavor, since the extra room lets water circulate around the grains). The tradeoff is heat — the roasting oven pushed the plant’s interior about 10°C above the outdoor temperature on the day of the visit.