I remember reading something where coffee was referred to as caf, but I don't remember what it actually was. It didn't work for me though as the word's too similar to the real world word for it, and it felt like they'd made the change just for sake of it.
In a different story (The Deeds of Paksenarrion), a brew called Sib fills a function similar to what coffee does, but it's never described exactly what it is or how it looks. It's just part of the camp rituals and in my meaning it works a lot better.
It's probably one of these things that varies from reader to reader and book to book though. I still think that even after considering all of the advice given here (and in other places), you'll have to be honest with yourself and stick to your gut feeling.
In a different story (The Deeds of Paksenarrion), a brew called Sib fills a function similar to what coffee does, but it's never described exactly what it is or how it looks. It's just part of the camp rituals and in my meaning it works a lot better.
It's probably one of these things that varies from reader to reader and book to book though. I still think that even after considering all of the advice given here (and in other places), you'll have to be honest with yourself and stick to your gut feeling.