The word “coffee” probably comes to us from Turkish, but before that the origins of the word are obscured in Arabic or Ethiopian origin.  Caffeea arabica is native to the Arabian peninsula and Ethiopia.

Tolkien does not refer to coffee outside of chapter 1, nor in The Silmarillion, The Lord of the Rings, or even in The Father Christmas Letters.  I assume that he enjoyed coffee from reading Letter 332 to his son Michael describing a flat that Merton College of Oxford provided him:

(7) The use of 2 beautiful common-rooms (at a distance of 100 yards) with free writing paper, free newspapers, and mid-morning coffee. It all sounds too good to be true (Kindle Locations 8842-8843)

To be honest, this mention of coffee – made from a tropics-loving plant which probably couldn’t grow in the Shire – I count as more evidence that Tolkien told this tale to his children (at least the beginning chapters) right off the cuff.  Dwarf names he already knew and which didn’t match the world the story later turned out to inhabit, coffee which he might have wanted as a guest at supper but which didn’t match the botany of that land.  “Papa, tell us another story.”  Yes, little ones.  I will always tell you another story and dredge it up out of any word-hoard that my young-parent-tired brain can access.  Pass the coffee, please.

• 01.046 and one for coffee,
• 01.047 A big jug of coffee had just been set
• 01.056 and coffee,

“coffee, n.” OED Online. Oxford University Press, March 2016. Web. 25 March 2016.