Sumac is a spice made from the dried and powdered fruit of the sumac tree. It has an acidic tang reminiscent of lemon or vinegar, and is often used in Middle Eastern cuisine to flavor salads and meat. The ingredient can also be found as a garnish, lending a pop of color to dishes like hummus. 23 percent of the population is familiar with sumac, with awareness highest among the Gen X cohort and Midwesterners.