tartness
tart-ness
noun
The quality of having a sharp, sour, or acidic taste, often found in fruits.
"The tartness of the cranberries balanced the sweetness."
noun
A sharp, critical, or slightly unpleasant quality in someone's manner or speech.
"Her tartness in the reply was unexpected."
Thesaurus
Synonyms: sourness, sour, jaundice, acrimony, bitterness, thorniness, acerbity