The expansion rate of tea leaves under cold water is low, the inclusions of tea leaves are not active, the dissolution rate is low, the taste is not ideal, and it is not easy to evaporate the flavor of tea leaves.

Hot water at a high enough temperature can increase the expansion rate of tea leaves, enhance the activity of tea inclusions, increase the dissolution rate, enhance the taste, and make it easier for the aromatic substances of tea to evaporate and emit flavor.