Any flavor or gustatory perception that could be roughly described as acidic or caustic is called a sour taste sensation. We use words like soapy, tart, corrosive, sharp, astringent, tangy, acerbic, rancid, vitriolic, biting, vinegary etc. to identify these flavors. They are visually identified with an icon of ‘Mr. Yuk’ who is a symbol for harmful substances. To make a binary description of a these sensations compare them to tasting a lemon.
Report the result using one of the following algebraic statements. If the two experiences are not comparable, then say that the sensation is not a sour sensation and express this as If the taste sensation is like a lemon, then say that it is tart. Write this as If the taste sensation is not like a lemon, then say that it is soapy and that The number is called the sourness. These relations are mathematically expressed by
Reference Constant for Sourness
The numerical constant associated with tasting a lemon has not yet been assigned.