In the case of Black tea, the leaves are plucked by hand and then left in the sun until they are pliable enough to be rolled without the leaf splitting. The leaves are then put into a tumbler and rolled. This process causes the juices from the leaves to react with the air and then oxidize. The green leaves turn black and are then fired in drying ovens. Black tea is the most common consumed in this country and is primarily cultivated in China, India, Sri Lanka, Africa and Indonesia. They are often flavored or scented with fruits or spices. The drying process leaves black tea with more caffeine than other types. Black teas can appear almost dark red or brown in the cup when brewed.