In its basic form, horchata is a rice-based drink made by soaking rice in water, typically together with cinnamon. The combination is blended, usually sweetened, and strained to reach a smooth, creamy texture. Horchata has a long history and most likely European and African roots.
In Latin America, the name is now mostly used as a generic term for a broad category of related drinks—they are based on grains, fruits, seeds, and sometimes even herbs and spices. Horchata most likely originated in Mexico, where it has been known since the 16th century.
Many believe it was based on ancient European or Roman drinks that were made with barley. It was also probably influenced by the eponymous Valencian horchata—made with tiger nuts—that potentially has its origins in Nigeria, where it is called kunnu aya.