Pretty sure Harry had some in the last book. And I think butterbeer is like hot buttered rum. But that is just my guess on the subject. I think I remember something about someone having too much of it. I forget where.
They toasted Moody with firewhiskey in book 7, but by then Harry is of age.
Butterbeer only makes a house elf “drunk”. It is not alcoholic, because Lupin gave one to Harry in POA.