These enzymes are present in epidermis tissue cells, spatially separated from their substrates. This is followed by a true rolling step in which the tea leaf tissue is completely macerated by conventional crank rollers under pressure.
Once done by hand but now performed mainly by machine, rolling transforms the flat leaves into mesmerizing twists, coils, balls or spears.
The rolling process physically crushed the leaves, opening sand exposing the leaf matrix and cellular compartment providing a more homogenous mixture for oxidative reactions and amore extractable matrix for brewing.
Rolling times vary between ten minutes and one hour. Young leaves are rolled under lighter pressure and for shorter duration compared to older leaves, in order to prevent the leaf breakage and yellowing that results from hydrolysis of chlorophyll and autoxidation of polyphenols.
In general, lightly rolled teas have mellower and gentler flavors, while leaves rolled with greater pressure break up into smaller pieces and form brews that are more brisk and intense.
Rolling of tea leaves
