sourness

happamuus The quality or condition of being sour, usually said of human personalities.

1811 Mrs. Ferrars was a little, thin woman, upright, even to formality, in her figure, and serious, even to sourness , in her aspect. — Jane Austen, Sense and Sensibility, http://etext.virginia.edu/etcbin/ot2www-pubeng?specfile=/texts/english/modeng/publicsearch/modengpub.o2w&act=text&offset=82200147&textreg=2&query=sourness&id=AusSens Chapter 2.1.