Five flavors

Acridity, sourness, sweetness, bitterness, and saltiness. Medicinals or foodstuffs of different flavors have different actions.

• Acridity can disperse and move;
• sourness can contract and astringe;
• sweetness can supplement and relax (i.e., relieve pain and tension);
• bitterness can drain and dry;
• saltiness can soften hardness and induce moist precipitation.

These actions are explained by modern pharmacy as follows: Acrid medicinals contain volatile oils; sour medicinals contain organic acids; sweet medicinals contain sugars; bitter medicinals contain biological alkalis, glycosides, or bitter substances. In addition to the five flavors, there is a sixth, blandness, which has a water-disinhibiting action. According to Plain Questions (素问 sù wèn), the flavors can be classified as yīn and yáng: Acrid and sweet-effusing (i.e., diaphoretic) and dispersing medicinals are yáng; sour and bitter upwelling (i.e., emetic) and discharging (i.e., draining) medicinals are yīn; salty upwelling and discharging medicinals are yīn; bland percolating and discharging medicinals are yáng. According to The Comprehensive Roots and Grasses (本草纲目 běn cǎo gāng mù), there is a relationship between flavor and bearing: no sour or salty medicinals bear upward; no sweet or acrid ones bear downward. No cold medicinals float; no hot ones sink.