change taste vs sour

change taste is not a noun while sour is a noun.

Word	Noun	Adjective	Verb	Adverb
change taste	No	No	Yes	No
sour	Yes	Yes	Yes	No

As verbs, sour is a hyponym of change taste; that is, sour is a word with a more specific, narrower meaning than change taste:

Other hyponyms of change taste include dulcify, dulcorate, edulcorate, sweeten, bitter, acetify, acidify, acidulate.

change taste (noun)	sour (noun)
	the property of being acidic
	the taste experience when vinegar or lemon juice is taken into the mouth
	a cocktail made of a liquor (especially whiskey or gin) mixed with lemon or lime juice and sugar

change taste (adjective)	sour (adjective)
	having a sharp biting taste
	showing a brooding ill humor
	inaccurate in pitch
	smelling of fermentation or staleness
	in an unpalatable state
	one of the four basic taste sensations; like the taste of vinegar or lemons

change taste (verb)	sour (verb)
alter the flavor of	go sour or spoil
	make sour or more sour