Difference Between Bitter and Sour


Main Difference

The main difference between bitter and sour is that sharp and pungent taste substance is known as bitter and substance with acidic taste is known as sour.

Bitter vs. Sour

Sour taste arises from higher acidic foods. Bitter derived from those foods that are obtained from cultivated soil. Bitter food detoxifies the body, also help in weight reduction and provide antibiotics, antiseptics and anti-parasitic qualities. Sour food can increase the body’s ability to absorb minerals, cleanse tissues in the body, and help digestion and circulation. The bitterness of substances is compared with the bitter-taste threshold of quinine that has a value 1. Sourness threshold estimates with dilute hydrochloric acid, which also has value 1. Bitter is very sensitive among all tastes; a large number of toxic substances found in nature are bitter. Sour taste is indicative of acidity. The perception of bitterness is easier by the merging of taste receptors and a G protein (gustducin). While sour taste is indicated by the concentration of hydronium ions in the hydrogen ion channels. Bitter food has earthy flavors like green leaves, bitter gourd, etc. Food that is rich in acids particularly generate sour taste. Chemical compounds like quinine cause bitterness of taste. Sour taste is due to organic acids present in the sour foods. According to Democritus being a philosopher, he thought for a living that when you chew on your food, and it crumbles into little bits, those bits eventually break into basic shapes. Bitter is “spherical, smooth, scalene and small,” in shape while sour is “large in its atoms, but rough, angular and not spherical.”


Comparison Chart

Basic substancesAcidic substances
Alkaline pH i.e. (7 to 14)Acidic pH i.e. (0 to 7)
Unpleasant and disagreeableThe sharp or tangy taste
Often an unpleasant tasteNot an unpleasant taste
Coffee, bitter gourd, olives, citrus peel, etc.Lime, lemons, oranges, grapes, etc

What is Bitter?

The bitter taste is very sensitive among all tastes. Most natural toxic substances are also known to be bitter. This is feasibly one of the reasons why we always relate bitterness with unpleasantness. Although, occasionally bitterness is seen as helpful and this taste is intentionally added via bettering agents. Bitterness is concluded to be unpleasant, sharp, or disagreeable. The taste receptors for bitterness are monomeric or surface-bound that determines the various bitter ‘ligands.’ Bitter tasting food is mostly observed to be toxic and therefore, different processing techniques are used to detoxify these foods that make them more eatable. Bitter compounds and acids might be increased or decrease each other, depending on the concentrations, the food stimuli, and the experimental methods involved. Bitter is naturally an unpleasant taste. A wide variety of compounds with various chemical structures induce bitterness. Many bitter substances are toxic, and it is also believed that bitterness functions to alert against eating possible harmful foods. Bitter substances necessitate polar, i.e., electrophilic or nucleophilic and hydrophobic groups and compelled to moderately dissolve in water. The bitter taste is usually recognized at the back of the tongue, but few substances are also recognized on the tip of the tongue. The natural action of bitterness can elaborate on several processes that depend on the structure of compounds that gives a bitter taste.


Health Benefits

  • Helps to cleanse and detoxify the liver
  • Bitter food is richly in vitamins and minerals
  • It helps to reduce food cravings which lead to weight loss
  • It triggers taste buds that activate the enzyme production and improve bile flow which regulates the digestion properly

What is Sour?

Sour is a taste that is generally associated with acidity. The sour taste is usually associated with food that is rich in acids. Citrus fruits such as lemons, grapes, tamarind, oranges, etc. have a sour taste. Some products also give a sour taste when they are getting spoilt. e.g, wine produces a sour taste if it’s not stored correctly and milk produces a sour taste when it is spoilt. Hydrogen ions or atoms generates sourness in food. The increase in the number of ions in the food also increases its sourness. Some people do not like sourness although it has many health benefits. Sour food increases the body’s ability to soak up minerals and cleanses tissues in the body. Food that has sour taste also assists in digestion and circulation. Sourness is bearable when it is not severe but becomes miserable when strong. It supports us to avoid unripe fruits and damage our tissue with acids. In human beings acids causes salivation, which elevates the bicarbonate secretions, i.e., the main buffering agent in saliva.

Health Benefits

  • The sourness activates the salivary glands, which energizing the appetite.
  • An organic acid found in sour foods triggers the nutrient absorption in the body, e.g., citric acid improves iron absorption; lactic acid helps maximize calcium intake and more.
  • Sour cherries and apples help to treat fibromyalgia and chronic fatigue syndrome.
  • It is good for digestion and improves the immune system.
  • Also helps to maintain lower sugar levels.
  • Sour food is also used to keep electrolytic balance in humans.

Key Differences

  1. Bitter is a sharp and pungent taste, on the other hand, sour is an acidic taste.
  2. Bitter substances have basic pH on the other hand sour have acidic pH.
  3. Sour flavors are related to acid conversely bitter tastes are mostly concerned with alkaline substances in food.
  4. The bitter taste is controlled by the extent of alkaloid on the flip side sourness is rely on the number of hydrogen ions.
  5. Bitterness is usually said to be toxic while sourness is generally contempt as acidic taste.


It is concluded that bitterness is a distasteful and disgusting or nasty foul taste and sourness is a symptom of acidity.

Aimie Carlson

Aimie Carlson is an English language enthusiast who loves writing and has a master degree in English literature. Follow her on Twitter at @AimieCarlson