sourness vs acidity

sourness and acidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
sourness	Yes	No	No	No
acidity	Yes	No	No	No

As nouns, sourness and acidity are synonyms defined as:

Other synonyms of sourness include sour.

As nouns, acidity is a hyponym of sourness; that is, acidity is a word with a more specific, narrower meaning than sourness:

sourness: the taste experience when vinegar or lemon juice is taken into the mouth
acidity: the taste experience when something acidic is taken into the mouth

Other hyponyms of sourness include acidulousness.

sourness (noun)	acidity (noun)
the property of being acidic	pH values below 7
a sullen moody resentful disposition	the property of being acidic
the taste experience when vinegar or lemon juice is taken into the mouth	the taste experience when something acidic is taken into the mouth