In preparing unfermented tea, the oxidizing enzymes are killed by steamblasting the freshly plucked leaf in perforated drums or by roasting it in hot iron pans prior to rolling . The leaf is then subjected to further heating and rolling until it turnsdark green and takes a bluish tint. the leaves are finally dried toa moisture content of 3 to 4 percent and are either crushed into small pieces or ground to a powder
with the inactivation of polyphenol oxidase, the polyphenols are not oxidized and therefore remain colourless, allowing th processed leaf to remain green. the absence of theaflavins and thearubigins in the finish leaf also gives the beverage aweaker flavour than black tea .