Unknown strain that smells like coffee...?

what would make two out of my 4 plants have a distinct coffee smell? a couple key things 2 point out is that they are 2 weeks into flower, and the 2 out of the four that smell like coffee are a kind of a unknown strain. i say kind of unknown because i seem to remember the seeds coming from a couple grams of either west valley bubba kush, or bubba kush, key word "seem". the bag they are in now has a sour desiel lable so i am basically asking if one of those strains may put out a distinct coffee smell? if that is not the case perhaps i am doing something wrong? but it smells pretty good so i hope its just right ... true newbie here, first time grow, any type of info is helpful, thanks!