AYURVEDIC PERSPECTIVE ON SOUR
Sour refers to anything fermented or acidic.
When something spoils or goes rotten it becomes sour. Sour taste in Ayurveda generally refers to fermented foods as in "the milk has gone sour," or acidic foods. Sour foods include yogurt, wine, beer, miso, and pickles. Acidic fruits like citrus and subacidic fruits like peaches are also considered sour, but where ferments heat the blood, sour fruits cool the blood.
Sour and Secretions
Sour pacifies Vata. Sours are secretagogues. They moisten and refresh a dry palate, encouraging secretions throughout the GI tract. These might be salivary secretions that improve taste, gastric secretions in the stomach that improve digestion, or a moist colon that facilitates smoother, looser bowel movements.
Sour Spoils the Blood
Sour ferments are hot and may spoil the blood, aggravating Pitta. Since all ferments are pre-digested by bacteria, they are readily absorbed through the GI tract. Sours thus increase the blood (rakta). In Chinese medicine they "generate" the liver. Since ferments are already digested, they contain metabolic byproducts or "bacteria poop." It is the bioavailability of nutrients combined with irritating metabolic byproducts that heat up metabolism in all tissues (dhatu agni), stimulate the liver, and cause the blood to spoil. Heavy ferments also aggravate Kapha. Sour increases flabbiness of tissues and decreases the strength of the sense organs.
Sour Increases Desire
Intellectuals love wine because it dilates blood vessels and focuses the mind. When our desires aren't satisfied it could lead to "sour grapes," as in the case of Aesop's fable, "The Fox and the Grapes." Grapes are supposed to be sweet, and nobody likes eating grapes that have turned sour. If we have sour grapes, our heart rejects the object of our desire.
Sour Fruits
Sour fruits are more
sattvic than ferments. They refresh and cleanse the palate. Think of a lemon sorbet between courses at a fine French restaurant. Generally, sour fruits heat digestion, but not the blood. Sour fruits come in two categories: acidic and subacidic. Acidic fruits include citrus fruits like
lemons,
limes, and
oranges. Citrus fruits strongly pacify Kapha. However, most sours like lemons exhaust Pitta-Vata livers so caution is required. Mild sours that are also sweet (applesauce, blueberries) are exceptions to the this. Subacidic fruits include
peaches,
apricots,
cherries,
apples. Subacidic fruits are the most sattvic of all sours. Many subacidic fruits pacify Pitta-Kapha because they decongest the liver and extract hot toxic bile from the liver.
Sour and Chinese Medicine
In Chinese medicine, sour taste is considered cooling because sour taste includes astringent taste.
Pomegranates and
cranberries are special medicines in Ayurveda because they are examples of sours with strong astringency. These sours focus dispersed energy, bringing the spirit back to the heart. They are also valuable digestive tonics because: (1) sourness aids digestion, (2) the cool quality soothes inflammation, and (3) astringency restores tone to distended tissues.