User: Tell me about the discovery of coffee bean?
Assistant: Coffee was first discovered by the 9th century Ethiopian goat-herder Kaldi. According to a story written down in 1671. Kaldi noticed that his goats behaving erratically when eating the coffee bean in a region called Kaffa in Ethiopia. It made its way north, across the red sea into Yemen in the 15th Century. It then started to be grown across the world.