unripe vs unripened

unripe and unripened both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unripe	No	Yes	No	No
unripened	No	Yes	No	No

As adjectives, unripe and unripened are synonyms defined as:

Other synonyms of unripe include green, immature.

unripe (adjective)	unripened (adjective)
not fully developed or mature; not ripe	not fully developed or mature; not ripe
not fully prepared