Ayurveda says that fire is the predominant element in sour foods. Sourness is found predominantly in fruits, fermented foods like yogurt and organic acids like oxalic acids. Oxalic acid is poisonous and should not be eaten in large amounts. Sour taste is similar to the sweet except that sour is hot but sweet is cold.

Both are heavy and somewhat oily. Fermentation yields heat, as this is the process of combustion. Earth is the second predominant element in the sour taste and there is also some water present in this kind of food. Sour taste tends to increase all elements but air. It is thus the choice of air type persons.

The sour taste enhances salivation. The first step is the digestive process. Sour foods generally cleanse the internal system and also stimulate the appetite. The sour type of food is often carminative and causes perspiration also due to the heat producing qualities. Over consumption of fruits can perturb the fire element, which leads to excess catabolism. The first evidence of this is usually the muscle weakness and/or diarrhea. Dark circles around the eyes are another indication that has been carried too far and should be balanced by proper tonifying of the food, particularly those that are related to kidney-adrenal functioning. One of the most popular sour foods in India is Tamarind. This is prepared as chutney, juice or a paste that is often used for alcoholism. In western countries rose hips, lemons, limes, raspberries etc used as the main sour foods while in India the mangoes and tamarinds are used mainly in India. It is important to note that each fruit has some specific properties as well as the general ones.

Fruit is more eliminative than building. According to Ayurveda, the predominantly catabolic effects of fruit, the body begins to consume its own earthiest parts, joints and bones, which gives the benefit of essential elements. So, fruit fast is good for people who have constantly consumed heavy and junk foods. Sour foods are generally purifying and they help in digestion and impart strength to heart and other organs of the body.