sourness

Etymology

From Middle English sowrenesse, sournesse, from Old English sūrnes (“sourness”), equivalent to sour + -ness.

noun

1. The quality or condition of being sour, usually said of human personalities.
   Mrs. Ferrars was a little, thin woman, upright, even to formality, in her figure, and serious, even to sourness, in her aspect. 1811, Jane Austen, chapter 2.1, in Sense and Sensibility