acerbity

Sourness of taste, with bitterness and astringency, like that of unripe fruit.

Harshness, bitterness, or severity

acerbity of temper, of language, of pain

“Well ?” I repeated with some acerbity. I had been wondering for the last ten minutes how many more knots he would manage to make in that same bit of string before he actually started undoing them again.

Something harsh (e.g. a remark, act or experience).

[…] the recollection of that yesterday […] made him bear with the meekness and patience of a true-hearted man all the worrying little acerbities of to-day;

This opera was mainly in the style of late Puccini, with acerbities stolen from Stravinsky.