The rolled leaves are spread on fermenting beds and left to ferment for a period of 3 to 4 hrs. The leaves are loosely spread to a thickness of 1 or 1.5. inches. Good fermentation results in the colour of the leaf to change to reddish brown giving off the characteristic aroma after the juices in the rolled leaves react with each other and the air. The Fermentation process is conducted at 80-90% humidity and the temperature is maintained at 70-80° Fahrenheit. A slight rise in temperature gives the tea a burnt taste whereas a slight fall in temperature stops the fermentation. During fermentation the leaves first heat up due to the chemical reactions and subsequently begin to cool down. A correct assessment of the timing, when the leaves start cooling, is needed to determine when to halt the process of fermentation.