Origin of describing emotions with adjectives associated with taste

Solution 1:

All of the adjectives existed in Old English and Middle English. They had, more or less the same meanings and usage as their modern counterparts.

The words are unremarkable in their development:

They start off as direct, literal descriptions of tastes:

This drink is salty, sour, sweet, bitter, etc. (in which the Old/Middle English words would be used) and then, by extension "She is salty, sour, sweet, bitter etc."

(Old English, especially, was very fond of allegories, riddles, puns, similes and other word play.)

The Old English Translator, under the entry for "sour" gives

scrípen Strong adjective

literal of taste harsh sour tart; of smell pungent; of color deep dark;

It then gives the extended meanings for the extended attributes that can be applied to people and emotions:

severe, rigid, strict, stern, austere, as the opp. of kind, pleasant, severe, gloomy, sad, troublesome, hard, irksome,

It also has

þurhbiter Strong adjective

very bitter; sour; perverse; exasperating

Which is clearly literal and figurative.