Sour

The sour taste occurs because of the stimulation of hydrogen ions which trigger the sour taste receptors on the tongue. The more acidic a substance, the more hydrogen ions will be released.

The sour taste comes from acidic substances including citrus, fermented foods, tannins, and vinegars. Sour foods and herbs absorb excess moisture, whilst also increasing the production of saliva. Energetically, sour substances tonify the lungs, playing a role in disease prevention. Excessive use, however, can result in malabsorption of nutrients.

Examples of sour herbs include rosehips (Rosa canina), raspberry (Rubus idaeus), rhubarb (Rheum palmatum) and schisandra (Schisandra chinensis).