There are in total five basic tastes that we can perceive (though some say there are six). They are saltiness, sweetness, bitterness, sourness, and pungent taste or umami.
Taste buds help us in tasting our food. It is generally believed that there are specific spots on our tongue where we can perceive different tastes but that is not true. Today we are talking about what’s the difference between bitter and sour. Let’s go…
What is Bitter?
The bitter taste is usually considered the most sensitive and the most unpleasant taste of all the tastes. Some examples of bitter foods include bitter gourd, dandelion greens, bitter melons, dark chocolate, peels of lemon and orange, coffee, etc.
The bitter taste is produced by chemical substances like caffeine, nicotine, quinine, morphine, etc.
Though unpleasant, it helps in detoxifying the body, particularly the liver, activates the taste buds, and encourages enzyme production thereby helping in digestion, reducing craving for food thereby indirectly helping in weight reduction, etc.
What Is Sour?
A sour taste is also considered an unpleasant taste. A sour taste is usually associated with acidity and acidic taste. Some examples of sour food are citrus fruits like lemons, oranges, tamarind, vinegar (acetic acid), citric acid, etc.
This taste is created by hydrogen ions. When there is a high number of H+ ions in the food, the sourness also increases.
Though many don’t like the taste, such food can increase the body’s appetite and increases the body’s ability to absorb minerals and vitamins, and some sour foods like yogurt, buttermilk, pickles, etc. are probiotic in nature.
Difference Between Bitter and Sour
The ability to taste bitter is important for health researchers as a large number of toxic substances found in nature are bitter in taste. This ability to detect bitterness at its low levels gives a protective function.
Hence, bitter compounds are added to toxic foods so that we can’t consume them. On the other hand, food processing methods reduced the bitterness in foods so that they become palatable. The use of fire also made bitter a little neutral to us.
People do not like sourness as sour taste also prevents us from eating spoilt or unripe food like spoilt milk. It also helps in the ingestion of both acids and bases.
Bitter vs Sour Table
| Bitter | Sour |
| Sharp, pungent taste | Acidic taste |
| Examples: Olives, orange peels, coffee, etc. | Examples: Lemon, pickles, oranges, etc. |
| Helps in weight reduction and provides a boost to the metabolism | Increases absorption of minerals in the body |
| Bitter taste is measured in threshold of quinine which is 1 | Sour taste is measured in the threshold of dilute hydrochloric acid which is 1 |
Bitter and Sour Food Examples
Foods containing bitter taste include dark chocolate, unsweetened cocoa, marmalade, ginger ale, olives, etc.
Sour foods include foods such as lemon juice, grapes, spoilt milk, etc. Sour food also includes fermented foods like yogurt, pickles, etc.
How Sour and Bitter Tastes Are Understood by Our Body
Bitter substances are generally considered as sharp, pungent, and unpleasant. We can taste bitterness because of G protein gustducin and Type 2 taste receptor cells also known as T2Rs or TAS2Rs.
T2Rs consist of 25 different taste receptors. One of them is TAS2R38. Scientists use phenylthiocarbamide (PTC) and PROP (6-n-propylithiouracil), both synthetically developed bitter substances, to determine our bitter perception.
To some, these two may have no taste at all, for some they may be a little bitter, but for people who are called supertasters, these two compounds are extremely bitter.
Sourness is often perceived with the help of type III receptor cells. H+ ions are abundantly present in sour or acidic foods. These ions enter into the type III receptor cells through H+ ion channels or proton channels.
It is through this way, we can taste sourness. Another way we can perceive sourness is some acids can easily penetrate these cells and those hydrogen cells stop the potassium channels.
Threshold Substances for Bitter Taste and Sour Taste
Bitterness is rated relative to quinine which has a reference index of 1. Brucine has an index of 11 (it is more bitter than quinine).
The most bitter natural substance is amarogentin, a compound present in the roots of Gentiana lutea plant. The most bitter synthetic substance is Denatonium which has a reference index of 1,000.
Sour taste is rated in relation to dilute hydrochloric acid whose sourness index is 1. Tartaric acid has a sourness index of 0.7, citric acid has an index of 0.46, and carbonic acid has an index of 0.06. (Any acidic substance whose sourness index is above 1 is more sour and below 1 is less sour than dilute hydrochloric acid).
Is Vinegar Bitter in Taste?
Vinegar can have both bitter and sour tastes. Store-bought white vinegar is usually more bitter but apple cider vinegar is more sour than bitter.
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