Stalk Extraction 
The extraction of stalk from made tea is one of the major problems in the sorting process. Stalk-free tea can be produced through fine plucking, light rolling, and avoiding drastic treatment to the leaf during processing. Unfortunately, such procedures are not always economical. Red stalk and fibre often appears and their removal becomes necessary. At present, the Myddleton is the machine most commonly used for stalk extraction. In this machine, there are two trays with bosses on the surface. During processing, the particles are hopped through these bosses and are thus separated. Java tunnels and waterfalls, which operate on the varying specific gravity of tea particles, are also useful in stalk removal. There is also the more recently developed Andrew Breaker, with its flute rollers which break up leaf but leave stalks intact. Japanese tea technologists have also invented a system based on the variation of moisture levels between leaf and stalk particles. Though the machine works well in principle, its output is low to cope with the needs of a modern factory. This, however, is true of most stalk extraction systems. The presence of stalk and fibre is controlled at best, not eliminated. A fine balance needs to be maintained between the level of control, efficiency and market price.
