ginger beer vs drinkable

ginger beer and drinkable both are nouns.

Word	Noun	Adjective	Verb	Adverb
ginger beer	Yes	No	No	No
drinkable	Yes	Yes	No	No

As nouns, drinkable is a hypernym of ginger beer; that is, drinkable is a word with a broader meaning than ginger beer:

ginger beer: carbonated slightly alcoholic drink flavored with fermented ginger
drinkable: any liquid suitable for drinking

Other hypernyms of ginger beer include beverage, drink, potable.

ginger beer (noun)	drinkable (noun)
carbonated slightly alcoholic drink flavored with fermented ginger	any liquid suitable for drinking

ginger beer (adjective)	drinkable (adjective)
	suitable for drinking