Agua de horchata is a traditional Mexican drink made from rice, water, and sweeteners like sugar and cinnamon. Its origins can be traced back to pre-Columbian times when the Aztecs and other indigenous groups in Mexico would make a similar drink using different grains and seeds. One theory suggests that the name "horchata" comes from the Latin word "hordeata," which means "made from barley." This is because the original recipe used barley, which was later replaced with rice when it became more widely available in Mexico. Another theory suggests that the drink was brought to Mexico by the Moors during the Spanish conquest. The Moors had a similar drink called "horchata de chufa," which was made from tiger nuts. This version of horchata is still popular in Spain today. Regardless of its origins, agua de horchata has become a beloved beverage in Mexico and other parts of the world, and its refreshing and creamy taste makes it a popular choice on hot summer days.