Adi grew up without caffeine at all, so she doesn't really.... take to coffee when she's first introduced to it. She starts out liking tea better, but eventually will drink either one depending on her mood.
Koreal... makes wizard coffee. Like, super-concentrated, high-octane, might-kill-a-normal-person coffee, to fuel his days-long study/spellwork. He'll drink tea if you offer him some, especially to be social or polite, but for actually getting a functional caffeine fix? Wizard coffee.