Steaming
Steaming is the kill-green method used for almost all Japanese green tea: fresh leaves are exposed to steam for seconds to two minutes to stop oxidation.
Definition
Steaming (蒸し, mushi) is how Japanese green tea is fixed. Fresh leaves pass through a steam chamber, usually a rotating drum with stirring arms, which heats them evenly and denatures the oxidizing enzymes. Steaming was also the main fixing method in Tang and Song dynasty China before pan-firing took over in the Ming dynasty; Japan kept it. The modern sencha method of steaming followed by hand rolling and drying is credited to Nagatani Soen of Ujitawara, near Kyoto, in 1738. Steaming time defines style. Standard sencha (futsumushi) is steamed for roughly 30 to 60 seconds. Light steaming (asamushi), under about 30 seconds, keeps the leaf needle-shaped with a clear, light, aromatic cup. Deep steaming (fukamushi), about 60 to 120 seconds or more, breaks down the leaf structure, giving small, broken particles and a dark green, cloudy, full-bodied cup with less astringency. After steaming, the leaf is cooled, then rolled and dried through a series of machines that mimic the old hand-rolling process. Steamed teas keep more chlorophyll and more of the leaf's grassy, marine aromas than pan-fired teas. China still makes a few steamed green teas, such as Enshi Yulu from Hubei.
In Depth
Brewing steamed teas: 70-80°C (158-176°F) for sencha, 1-2 minutes; 60-70°C for gyokuro and high-grade sencha. Use 4-5 g per 150-200 ml in a kyusu. Fukamushi releases flavor fast because of its fine particles, so steep it for 30-60 seconds and use a teapot with a fine mesh filter.
Flavor markers: steamed teas taste of fresh grass, spinach, seaweed and sweet vegetables, with umami from amino acids. A Chinese tea described as "Japanese style" usually means it was steamed.
Buying: labels often state asamushi, chumushi (medium) or fukamushi. Fukamushi is common from Shizuoka's Makinohara plateau and Kakegawa; asamushi is more traditional in mountain areas such as Kawane and Uji. Deep-steamed leaf also stales faster once opened, so buy it in smaller bags.
See Also
- Japanese Green Tea
- Sencha Processing