acidulousness vs austereness

acidulousness

noun
  • A state of or tendency toward being acidulous or somewhat sour or acid. 

austereness

noun
  • harshness or astringent sourness to the taste; acerbity. 

  • severity; strictness; austerity. 

How often have the words acidulousness and austereness occurred in a corpus of books? (source: Google Ngram Viewer )