Horchata, also called orxata, is a refreshing drink made from combining grains, nuts or tubers like rice, barley almonds or tiger nuts, with sugar, and sweet spices like cinnamon. Water is added to the primary ingredient until the result is a grain, vegetable, or nut milk, which is then spiced and sugared to produce the beverage. Food historians suggest that the drink may have initially been a form of almond milk carried by Arabic travelers, which was thus introduced to Spain.
Spanish immigrants to the new world made it a favorite beverage in many parts of Mexico and South America. It is particularly popular in El Salvador, where it may also incorporate the new world flavor of chocolate. The early use of tiger nuts in horchata was especially common in Valencia, Spain.
Tiger nuts refer to long edible tubers from the plant cyperus esculentus. In Spain they are called chufa, horchata made from chufa is called horchata de chufas. This variant of horchata is not common in South America as other grain or nuts sources are much more easily obtained.
In El Salvador, people may make their own horchata, but there are many commercial varieties and horchata powder. Often Salvadorian horchata does not use rice, but instead uses herbs and may employ calabash seeds or sesame seeds as the primary grain or nut-based flavoring. The horchata of this type is strained so that the end texture is smooth and milky.
There is some debate about whether horchata should be prepared using milk instead of water. Some recipes call for the addition of dairy milk, or other milk substitutes. Others say the oldest forms of recipes likely did not include milk since it would not have kept well. Whether or not milk is used, horchata has a milky texture and consistency and is preferable when served ice cold. In many restaurants and festivals, large clear containers of iced horchata and other popular fruit punches and drinks are extremely inviting.
Horchata is not commonly available in standard US grocery stores, though you can find versions of it in Mexican and South American grocery stores. Despite its unfamiliarity in many parts of the US, QuikTrip convenience stores in some areas of the Southern US, including Georgia and Texas, offer a horchata frozen shake or drink that is quite popular. You can also find horchata served in some Mexican restaurants and in restaurants featuring Salvadorian cuisine.