Styles of beer go back at least to Mesopotamia. The Alulu Tablet, a Sumerian receipt for "best" ale written in Cuneiform found in Ur, suggests that even in 2050 BC there was a differentiation between at least two different types or qualities of ale. The work of Bedrich Hrozny on translating Assyrian merchants' tablets found in Hattusa, revealed that approximately 500 years later the Hittites had over 15 different types of beer.
