"My parents like beer."
Translation:Meine Eltern mögen Bier.
I wouldnt say theyre always feminine, but the nominative case of a plural word has the same article as nom fem singular noun, "die." In dative case, plural words use "den" as their article, which is the same as masc. akk. sing. nouns, but that doesnt mean it becomes masculine when its in dative case.
Im not trying to be pedantic, but I dont want someone to get the wrong idea by what you said (even though I know what you meant). :)