Sumac comes from a shrub native to the Mediterranean, and its history dates to ancient times. The Romans used sumac berries as a souring agent and flavoring before citrus fruits reached the region. Sumac still grows wild around the Mediterranean, including in Sicily and southern Italy; major sources today include Turkey and the Middle East.
Sumac berries, which are about the size of a peppercorn, grow in clusters and turn from green to crimson as they ripen. (There are many varieties of the shrub, and some of them—including many of those used as ornamental bushes in North America—are poisonous, so don’t be tempted to harvest sumac berries from your backyard. However, Native Americans traditionally used sumac berries to make a refreshing drink, and they also used both leaves and berries in tobacco mixtures.) The berries are picked by hand when mature but slightly underripe and then dried, still on the stem, in the sun for several days. The fully dried berries range from brick-red to almost purple in color. Although they are sometimes sold whole, they are more often ground to a coarse, slightly moist powder; the best-quality powders are a deep reddish-purple. Sumac has a clean, fruity fragrance and tart, fruity, astringent flavor, with a citrus tang but without the sharpness of lemon juice.
Sumac is widely used in cooking in Turkey and the Middle East, especially in Lebanon, Iran, and Iraq. The dried whole berries must be soaked or ground before use; occasionally, the berries are soaked to soften them and then are strained out, pressed to release all their juices, and the liquid used as part of the cooking medium for a stew or other dish. A simple salad of sliced onions seasoned with ground sumac is popular throughout the Middle East. Sumac flavors kebabs and grilled meats, fish, and chicken, and it is added to marinades for foods that will be roasted or grilled. It can be stirred into yogurt to make a marinade, or the seasoned yogurt can be served on its own as a dip or a condiment. Sumac is also sprinkled over rice, hummus, or baba ghanoush, along with a drizzle of olive oil, as a garnish and flavoring. It is an essential ingredient in the Middle Eastern spice blend za’atar.