T/YCCY 002-2018 Yi Jin Xiang

Scope

Main Technical Content: Yijinxiang Processing Technology The processing flow of Yijinxiang includes withering, rolling, fermentation, drying, and sorting. A.1 Withering The withering process is conducted in withering tanks. The ideal environmental conditions are a temperature of 25-30°C and a humidity of 60-80%. Intermittent blowing is used, with the fan being stopped for 0.5-1 hour every 3 hours. The withering process typically lasts approximately 12 hours, during which the leaves are turned over no more than three times. The ideal sensory criteria for withering include: - The leaf color changing from bright green to dark green and losing its luster; - The buds and leaves losing their turgidity; - The fresh leaves no longer having a grassy aroma and emitting a light fragrance; - The leaves becoming soft, with tender stems that can be bent but not broken; - The average moisture content being around 60%. A.2 Rolling Rolling is performed using 45, 55, and 65-type rolling machines. For the 45-type machine, the input amount of withered leaves is 15±2 kg; for the 55-type machine, it is 30±3 kg; and for the 65-type machine, it is 60±5 kg. The rolling time is controlled within 90-120 minutes, with a tea strip production rate of ≥85%. A.3 Fermentation The fermentation process uses dedicated equipment at a temperature of 27-30°C and a humidity of 85%-93%. The fermentation time is approximately 3 hours, with one turning during this period. The ideal fermentation criteria include: - The grassy aroma disappearing and floral/fruity fragrances emerging; - The leaf color turning yellow-red. A.4 Drying Drying is conducted using chain-plate dryers: - First drying: Inlet air temperature 120°C, duration 10 minutes, leaf layer thickness 1.5-2 cm, until the moisture content reaches approximately 25%. Remove from the dryer and cool for 1-2 hours. - Second drying: Temperature around 90°C, leaf layer thickness 2-3 cm, until the moisture content reach

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