Sumac (Rhus coriaria), also called Sicilian sumac, tanner’s sumach, and elm-leaved sumach, is not the same as fragrant sumach (Rhus aromatica) or Atlantic poison oak (Rhus toxicodendron). However, you can distinguish the types based on the color of the berries. The red ones are edible whereas the white are toxic. Staghorn sumac (Rhus typhina), for example, is not suitable for consumption. The Sumac family (Anacardiaceae) consists of hundreds of species. The tannin content is high and sumac has long been used in tanning leather and dyeing fabrics.
The Middle Eastern seasoning mix Za'atar (Zahtar, Satar) is a dry mixture containing sesame seeds, salt, herbs (thyme), and sumac. Winter onions, garlic, cilantro, mint, oregano, paprika, pimento, chili, sesame, and thyme go well with sumac. Sumac can also be sprinkled on top of hummus.
Dried and crushed, it is a popular spice found in Middle Eastern cuisine. The immature fruits and seeds can also be eaten. It has been used in traditional medicine for its lipid-lowering effects.1
The American Indians used sumac to make a sour drink. Since the staghorn sumac is indigenous to Europe, this is a healthy, refreshing drink that you can make at home. Place the sour berries in cold water and bring just to a boil so that the water turns pink. Pour the mixture through a towel to separate out the little hairs and then sweeten with sugar as desired.2
Collect sumac berries (1 cup berries = 1½ teaspons spice). Place the berries in a cool, dark place and let dry for a week or two. This makes it easier to separate the spice from the seeds. Grind the berries in a food processor or blender. Pulse until the seeds are primarily yellow and the red dust has separated from the seeds. Place a strainer, mesh, or flour sifter over a container and pour the mixture through in order to collect the spice in the container. You can sprinkle it on a variety of vegetable dishes or kabobs. You can also use it to make lemon pepper.4
From Wikipedia: The leaves and the bark were traditionally used in tanning and contain tannic acid. Dyes of various colours, red, yellow, black, and brown, can be made from different parts of the plant. Oil extracted from the seeds can be used to make candles.1
The sour taste of sumac comes from the fruit acids (apple acid, citric acid, and tartaric acid, as well as succinic acid, maleic acid, fumaric acid and ascorbic acid) it contains. All of the parts of the plant are also rich in tannins (hydrolyzable tannin, 4 % in the fruit); the particularly tannin-rich root bark was used as early as antiquity to tan leather and is used in traditional medicine to treat diarrhea. ...
The deep red colour of the fruit comes from anthocyanin pigments. To date, chrysanthemin, myrtilli, and delphinidin have been identified. The fruit contains about 15 % fatty oil.3
Rhus coriaria, commonly called Sicilian sumac, tanner's sumach, or elm-leaved sumach, is a deciduous shrub to small tree in the Anacardiaceae or cashew family, native to southern Europe. The dried fruits are used as a spice, particularly in combination with other spices in the mixture called za'atar.1