The partially withered leaves are packed in small cotton bags, loosely tied at mouth, and placed in open wooden troughs or boxes perforated at the sides with numerous holes, in which they are pressed and kneaded by the feet, to expel all superfluous moisture, the object being to extract all excess of tannin the principle to which tea owes its bitterness and astringency. If the leaves be fermented without previously going through this process, the tea will be too pungent and bitter. The fluid driven out through the holes is of a greenish, semi-viscid nature, the quantity expelled from the leaves being considerable. Properly evaporated, the leaves when pressed in the hand return to their regular shape, the stem bending double without breaking. The process of fermentation is accomplished by next emptying the leaves into bamboo baskets and covering them with cotton or felt mats, to cause a retention of heat and hasten the fermentive changes. Having been allowed to stand in this condition, the time requisite for this process, being learned only by experience, being more rapid in dry, warm weather than in cool and damp. If the leaves be allowed to remain in a heap after evaporating, so that heating by natural fermentation should occur, the tea will be greatly injured. The process is stopped by emptying the leaves and spreading them out on large mats, exposed to the sun’s rays. The effect of proper fermentation is to make the tea richer, smoother and more pleasing in flavor. Tea in this respect being like tobacco, which if dried over a fire when first cut, becomes so sharp and bitter as to sting the tongue. During the process of “sunning” the leaves are tossed up and turned over repeatedly, so that the whole may be diffused and thoroughly permeated by the sun. With bright sunshine one hour’s exposure is sufficient, after which they are ready for the final processes of firing and curling. One of the results of the sunning process is to evaporate in a greater degree the properties that produce nervousness or wakefulness in the tea.