The quality or condition of being sour, usually said of human personalities.(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "sourness" in a sentence
"The idea is to flavor the liquid well with the spices and extract all the sourness from the kokum."
"This is a brine pickle made without vinegar; the sourness comes from the fermentation process, as is traditional."
"Whenever I experience this, whenever a laconic sourness is thrust into my spirit, I close my eyes and seek for something inside me that can anchor me against the unpleasant wave that threatens to engulf me, cap-a-pie."