Tasting a Lemon – EthnoPhysics

Sourness is illustrated by this Mr. Yuck icon.

Any oral sensation that is somewhat sharp or unpleasant is called a sour sensation . We use words like soapy, tart, caustic, acidic, astringent, tangy, acerbic, rancid, vitriolic, biting, vinegary, and so on, to identify flavours in this category.

To make a binary description of sour sensations compare them to the reference sensation of 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 sour and express this as $\delta_{H} \! = \! 0 .$ If it is like tasting a lemon, then call it tart and write as $\delta_{H} \! = \! +1 .$ If a sour flavour is not like a lemon, then call it soapy and note this as $\delta_{H} \! = \! -1 .$ These relationships are concisely expressed by

$\delta_{H} \equiv \begin{cases} +1 &{\text{if a sour sensation is tart }} \\ \; \; 0 &{\text{if a sensation is not sour}} \\ -1 &{\text{if a sour sensation is soapy }} \end{cases}$

The number $\delta_{H}$ is called the sourness. Sour sensations are visually identified with an icon of ‘Mr. Yuk’ who is a symbol for harmful substances.

Reference Constant for Sourness

The numerical constant associated with a lemon has not yet been assigned. We are thinking about the pH of water.