In the manufacture of black tea there are four principal processes, withering, rolling, oxidizing and firing. During this time the leaf, of course, is continually losing moisture. When, in the process of withering, the leaf has obtained the proper degree of pliability, it is rolled either by hand or by a rolling machine. The rolling breaks up the oily cells in the leaf and gives to the tea leaf that twisted appearance by which it is so universally distinguished. At Pinehurst all the rolling is done by machines and the process requires about three quarters of an hour. After the leaf has been sufficiently rolled to break up the cells it is spread on table trays, in layers about two inches thick, for two or three hours, during which an additional or final oxidation takes place. The oxidizing room should be kept damp and as cool as possible. It is then taken into the drying or firing machines, and subjected to an even heat until the leaf has lost all of its moisture, and all the exudations which have come to the surface as a result of drying and rolling combined remain deposited as dry matter upon the surface of the leaf, which should then be crisp and fragrant. The best method of firing is to drive hot air over the tea by means of a fan.

The quality of the tea is largely dependent upon the care observed in its firing, and the temperature should not be so high as to dissipate all the volatile oils. On the other hand, the drying must be at a temperature sufficiently high and continued sufficiently long, to remove the moisture; otherwise rapid deterioration will take place. The treated tea is placed in air-tight cans or bins and allowed to remain until ready for shipping.