Chocolate is a usually sweet, brown food preparation of roasted and ground cacao seeds that is made in the form of a liquid, paste, or in a block, or used as a flavoring ingredient in other foods. The earliest evidence of use traces to the Olmecs, with evidence of chocolate beverages dating to 1900 BC. The history of chocolate began in Southern Mexico. Fermented beverages made from chocolate date back to 450 BC. The Aztecs believed that cacao seeds were the gift of Quetzalcoatl, the god of wisdom, and the seeds once had so much value that they were used as a form of currency.