Inspired by the classic pairing of dill and lemon, we chose sumac over citrus for its bright acidity, lemon-like familiarity, and stunning purple hues (if you’ve ever wondered what that purple spice on top of hummus is, that’s sumac!) Sumac appears in all kinds of global cuisines, and in ancient times sumac was used to add acidity to dressing and hints of tang and citrus to fish.