Tea rolling is an essential step in the processing of tea leaves that damages the cell walls, distributes moisture evenly on the outside of the leaves, and exposes enzymes to air, speeding up oxidation. Oolong, black, and puerh teas are rolled during processing, while green teas are rolled after the fixing step. Ball-style oolongs, like Tie Guan Yin, are rolled multiple times to achieve a tight, compact shape. Rolling can be done by hand, but machines are commonly used in modern tea production.
Temomi, or tea rolling by hand, is a traditional method that is still practiced today in some tea-producing regions. Temomi is done on a heated table called hoiro, coated with Japanese washi paper to absorb moisture. The tea leaves are shuffled lightly between the fingers and spread on the hoiro to remove extra moisture after steaming and dry the surface of the tea leaves. Rolling begins once the surface of the tea leaves is dry, with the tea leaves gathered together and rolled lightly at first to gently press the inside moisture out. As the moisture content inside the tea leaves goes lower, the tea leaves get pressed harder and harder to push out more of the remaining moisture. At this point, the tea leaves are rolled so heavily that they often tangle together in clumps and must be untangled by gently pulling them apart.
Once the tea leaves become loose again, shaping begins by rolling them in-between the hands over the hoiro to straighten the curled tea leaves. The tea leaves may then be placed on the hoiro to continue drying little by little. Finally, the tea leaves are beautifully aligned and realigned while rolling them on the hoiro until they become straight tea needles. This entire process takes about 6 hours.
Tea rolling machines have significantly increased productivity compared to the traditional temomi method. While tea production by hand is rare these days, the Tea Hand Rolling Preservation Associations in each tea-producing town aim to preserve the old traditions. These associations help to keep the art of tea rolling by hand alive and practiced by some tea farms that want to keep the traditional methods alive.