taster vs taste tester

taster and taste tester both are nouns.

Word	Noun	Adjective	Verb	Adverb
taster	Yes	No	No	No
taste tester	Yes	No	No	No

As nouns, taster and taste tester are synonyms defined as:

taster and taste tester: someone who samples food or drink for its quality

Other synonyms of taster include sampler, taste-tester.

taster (noun)	taste tester (noun)
someone who samples food or drink for its quality	someone who samples food or drink for its quality