National Geographic : 1912 Feb
O FERMENTING THE TEA After the leaves are brought to the factory they are spread out on trays or racks for about 24 hours and allowed towither. The leaves -I are then "rolled" (see page 169) in order to crush the leaves so as to liberate the juices. The leaves are then spread outinacool house, as shown in this illustration, and allowed to ferment for several hours to make the "black" tea of commerce. If"green" teaisdesired theleaves are not fermented. "Green" tea and "black" tea may come from the same tree; the difference is due entirely tothemanner oftreatment after picking.