The Hymn to Ninkasi is at once a song of praise to Ninkasi, the Sumerian goddess of beer, and an ancient recipe for brewing. Written down in c. 1800 BCE, the hymn is no doubt much older as evidenced by the techniques it details which scholars have determined were actually in use long before the hymn was written.
Want to make your own beer the very first way it was made without any homebrewing equipment, here you go: