In September, summer moves into fall around the edges of the day. The nights grow cooler, then the chill tiptoes into the corners of the dusks and dawns.
As the days creep shorter, wild plants are changing, too. Ive been waiting for this time, scoping things out for months to try to guess at whether it will be a "good year" for wild fruit. But, like any farmer, I worry that with the weather being so cranky, what started out looking good may end up being a washout.
I've been watching sumac closely for months. The crown jewel of this small tree or shrub are the burnished red fruit clusters held upright, resembling an Olympic torch. While there are several types of sumac, my favorite is the staghorn sumac, Rhus typhina, with branches that are covered with velvety fuzz like the horn of a stag.
This year's torrential downpours washed away some of the potency of the fruit, leaving some brown clusters on top, but they're still red on the underside. So I scout for the more sheltered of the sunny, dry slopes on which sumac likes to grow. I grit my teeth in envy at the gorgeous but car fume-saturated sumac trees that line the highway medians—too much pollution for foraging.
Instead, the neighboring farm lets me clip off fruit clusters from their sumac trees, but the farm manager anxiously rushes over to warn me that "those trees are the most poisonous plants in the country!" We tell him that poison sumac has white clusters and not red, and since that is the only part of the tree we are after, there is no chance of mistake. He still looks at us skeptically and shrugs—"Don't say I didn't warn you." In fact, many a sumac grove has been mistakenly knocked down in the belief that it is poisonous.
We are secretly glad that they don't care to share in our treasured stash. The fruit yields a fine claret-colored spice and flavor that is deliciously tart and clean tasting. Plus sumac fruits are high in vitamin C, A ,and antioxidants.
To harvest, find the most brightly colored clusters and use the finger test. You may feel a slight stickiness from touching the red cluster, and when you lick your fingers you will taste the tartness. Clip off at the base of the clusters with pruning shears as early in the season as you can, and dry sumac before it succumbs to insects or mold.
Making Sumac Spice
Right after harvesting, you can use the clusters as-is by dipping them in room temperature water overnight or until the water turns red, or you can make it in to a spice that will last for at least a year. Where we live in the Mid-Atlantic region, it tends to be humid, so I need to dry the plant under the heat lamps above my stove or in a dehydrator overnight. Our regular home oven is not low enough for the 125-150°F gentle drying heat.
After drying, I break up the clusters and toss the good ones in to a blender. The blender will separate the fruit from the sticks and seed, which I then push through a strainer. The mesh should be medium fine so that the fruit can go through but not the seeds and sticks. It's a fairly intensive process, but it's a great experience to see each step, from whole fruit to making your own spices. The spice will last more than a year stored in a cool, dry pantry.
You can also substitute and find piles of the purple brown European Sumac, Rhus coriraria spice in outdoor markets in Paris, or from speciality grocery and spice stores in the States and online. In a side by side taste test I conducted with chefs as well as flavorists, they unanimously voted for the staghorn sumac, for color and its taste, which is cleaner and brighter.
Sumac has long been used as a flavoring ingredient especially in the Middle East and Mediterranean. Sumac is most notably one of the distinguishing ingredients in za'atar , which is a combination of sumac with various herbs and spices. Traditionally, each family may have its own secret blend, but my own Foraged Flavor recipe for za'atar calls for equal amounts of sesame seeds, wild sumac, and thyme. Lebanese sprinkle za'atar on everything from flatbread to eggs, potato salad, and even lemony yogurt. My daughters top oatmeal and avocados with za'atar. We are on a za'atar jag.
Rachel Ray uses za'atar as a rub to flavor a chicken Caesar salad and Israeli-born London chef Yotam Ottolenghi embraces sumac and za'atar throughout his many cookbooks: turkey and zucchini burgers with sumac sour cream, za'atar spiced beet dip with goat cheese and hazelnuts, fried beans, sorrel and sumac, and roast chicken with sumac, za'atar and lemon.
With its citrusy notes, sumac also stands on its own and is most readily associated with savory dishes as a rub or seasoning on meat or fish like salmon a la Daniel Boulud. Kenji has a great recipe for sumac onions that can be scattered on a kale and chickpea salad. The onions take on a great lemony flavor.
And finally, sumac imparts a great refreshing flavor as a syrup in desserts, jellies and drinks, like the sumac soda above.