When started people to drink beer?

Answer 1

Beer is one of the world's oldest prepared beverages, possibly dating back to the early Neolithic or 9500 BC, when cereal was first farmed, and is recorded in the written history of ancient Egypt and Mesopotamia.

The earliest known chemical evidence of beer dates to circa 3500-3100 BC from the site of Godin Tepe in the Zagros Mountains of western Iran.