Sumac: The Sour Red Spice, and How It Differs From Poison Sumac

Sumac gives you lemony sourness without the juice. It’s a deep red, coarse powder with a sour, slightly astringent taste, and across the Middle East and the eastern Mediterranean it gets used the way other cuisines use lemon: sprinkled over rice and grilled meat, mixed with sliced onions, or blended into za’atar. And no, it isn’t poison sumac. The two are easy to tell apart, and with the ground red spice you buy in a shop, the question doesn’t come up.

At a glance

Culinary sumac vs. poison sumac

This is the question people ask most about sumac, and the answer is clear-cut.

The spice comes from Rhus coriaria. Poison sumac is Toxicodendron vernix, a different plant that was once placed in the genus Rhus and has since moved to Toxicodendron.² The two share a plant family, the Anacardiaceae, which also includes poison ivy and poison oak. Poison sumac contains urushiol, the same irritant found in those plants.¹

Katzer gives the field rule plainly: the fruits of Toxicodendron species are white to pale ochre, not red.⁴ Sumac sold as a spice is the ground red fruit of Rhus, so the question doesn’t come up in the shop. It matters only if you forage. North America has its own red-fruited sumacs, like smooth sumac (Rhus glabra) and staghorn sumac (Rhus typhina), and Katzer notes that Native Americans made sour drinks from the fruit of native species. If you forage, identify the plant with a regional field guide. This page isn’t one.

Since sumac belongs to the cashew family, the 2022 Molecules review suggests that people allergic to related foods be careful with it.¹

Flavor and the compounds behind it

Sumac tastes tart and sour with slightly astringent overtones. Its sourness is put down to malic acid, the acid also found in apples, and Katzer lists citric and tartaric acids among the organic acids present as well.⁵⁴ The 2022 review identifies hydrolysable tannins as the most prominent group of compounds in the fruit, followed by flavonoids and phenolic acids.¹ The deep red comes from anthocyanin pigments in the fruit skin.

In the kitchen, that means sumac adds sourness without liquid. That’s why it works as a finishing sprinkle where lemon juice would make a dish wet.

Origin and history

Rhus coriaria is native from Macaronesia and the Mediterranean to Afghanistan. It’s had a long second career as a tanning plant. It was grown in southern Italy as a source of tannin, and the species name coriaria refers to leather tanning. The English word comes, via Arabic as-summāq, from a Semitic root meaning “to be red.”⁴

• Greek medicine. The physician Dioscorides mentioned sumac in his writings, recording its use against flatulence and as a diuretic.
• Rome. Cooking the fruit in water into a thick, very sour essence for meat and vegetable dishes, still done in Lebanon, Syria and Egypt, was already common in Roman times, according to Katzer.⁴

You’ll often read that sumac was the Middle East’s main souring agent until the Romans brought lemons. We couldn’t find a source for that, or for a link to sorghum, which is sometimes described as a relative.

How sumac is used

• Turkey and Iran. Sumac is a very popular condiment in both countries, where the ground fruit is sprinkled liberally over rice.
• With onions. Mixed with freshly cut onions, it’s often eaten as an appetizer.
• Grilled meats. Döner kebab is sometimes flavored with sumac powder. Across the Mediterranean, sumac with salt and onions seasons roast meat, and in North Africa it’s rubbed on meat, chicken or fish.
• Salads and minced meat. Powdered sumac goes into salads or is served with minced meat for a lemony taste.
• Za’atar. Sumac is one of the main ingredients in the herb blend za’atar, which takes its name from a local wild marjoram. See za’atar.
• Sour essence. In Lebanon, Syria and Egypt, the fruits are simmered in water into a thick, sour liquid for cooking.

For more ideas, see sumac uses and cooking with sumac.

Buying and quality

Good sumac is deep burgundy to brick red, slightly moist and coarse, and smells fruity and sour. Brown, dusty powder has faded. Think of that as a rule of thumb, not a standard. Katzer notes that the ground spice is often mixed with salt, so check the label if you’re watching sodium. We found no international grading standard for sumac.

Storage

We found no published shelf-life figure for sumac from a regulator or standards body. Keep it sealed, away from heat and light, and judge it by its color and how sour it tastes.

Health claims

The best current evidence is a 2025 systematic review and meta-analysis of 15 randomized controlled trials with 917 participants. Taking sumac as a supplement was linked to modest drops in fasting blood glucose, insulin, LDL and total cholesterol and triglycerides, and a rise in HDL cholesterol, with no effect on body weight, BMI or waist size. The authors rated the certainty of that evidence as low for most outcomes (moderate for triglycerides and very low for several others), and noted that the trials came from a narrow set of countries, which limits how far the results apply.⁶ Those were supplement doses, not seasoning amounts, and the findings don’t show that sumac treats or prevents any disease.

There are lab studies on sumac’s antioxidant and antimicrobial activity, but they aren’t evidence of effects in people, so we don’t repeat them here. The 2021 review in Antioxidants describes sumac as safe with little toxicity, while calling for more toxicological studies and clinical trials.⁵

Substitutes and comparisons

• Sumac substitutes
• Za’atar substitutes
• Marjoram