The old CHOW office was across the street from Pancho Villa, one of the better taquerias in San Francisco’s Mission district, so we’re used to Mexican horchata made from rice. But the Spanish version is made by soaking ground chufa or tiger nuts (which are not really nuts but tiny tuberous roots grown around Valencia), and then adding cinnamon and sugar.
The name supposedly comes from a remark by King James I of Aragon when he took Valencia from the Moors. He was offered a drink of the stuff and quipped, “Aixo no es llet, aixo es or, xata!” (which roughly translates into “This isn’t milk, this is gold, cutie!”). The “or, xata” turned into horchata. Supposedly.
You can buy chufa nuts from La Tienda. Bonus: they’re high in potassium and iron, making horchata a good sports drink.