Oolong tea lies somewhere in the middle between green and black tea. It is fermented like black tea, but the process is stopped part way through. The crucial stage in the process is to stop the fermentation process at exactly the right time, and the best time to stop the fermentation is when the leaves are 30% red and 70% green. They are then 'rubbed' repeatedly to release the enzymes and juices necessary to produce good flavor, aroma, and texture. The next step is to heat the leaves. This method produces a unique balance between green tea's delicacy and black tea's depth. The tea master then grades the tea flavor and characteristics of each batch. Formosa oolong from Taiwan is considered one of the finest oolong teas.