Sourness
Any flavors or gustatory perceptions made when a substance in the mouth reacts chemically with nerves of the tongue and palate are called taste sensations. Any flavor 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. To make a binary description of a sour sensation compare it 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
 Flowers and fruit of the lemon tree, also known as Citrus x limon.

$\delta_{\sf{H}}=0$

If the sensation is like tasting a lemon, then say that it is tart. Write this as

$\delta_{\sf{H}}=+1$

If the sensation is not like tasting a lemon, then say that it is soapy and that

$\delta_{\sf{H}}=-1$

If it is both like and not-like tasting a lemon, then say that it is a composite sensation and

$-1 \le \delta_{\sf{H}} \le 1$

The number $\delta_{\sf{H}}$ is called the sourness. We use a picture of a lemon as an icon for sour taste sensations. You can always click on icons to come back to a page like this for easy reference.

 Summary
 Adjective Definition Sourness $\delta_{\sf{H}} \equiv \begin{cases} +1 &\sf{\text{if a sensation is tart }} \\ -1 &\sf{\text{if a sensation is soapy }} \end{cases}$ 2-8
page revision: 52, last edited: 01 Jan 2014 13:51