Purple Leaf "Zi Cha" Pu-erh Tea
During the hot, humid summer and fall seasons a portion of tea tree buds are purplish red colored. The source of the color is anthocyanin, which changes color along with cell sap acidity. High levels of acidity lead to red color, while medium acidity is more purple, and high alkalinity tends toward indigo. Anthocyanin is a phenol material, and along with catechin is an important component in the medicinal effect of tea. Purplish red tea results from an inheritied reaction to unfavorable hot and humid summer environmental conditions, providing the tea tree with a mechanism for fighting scorching ultraviolet rays.