Arrow-right Camera
Subscribe now

How to ember grill sweet potatoes for smoky, caramelized flavor

Grilling enhances the flavor of vegetables.  (Scott Suchman/For the Washington Post)
By Joe Yonan Washington Post

Grilling vegetables is not like grilling meat. I know that, you probably know that, and Steven Raichlen certainly knows that.

For one, as Raichlen tells me, “a steak is a steak is a steak, but with vegetables, there’s such an incredible diversity of flavors and textures and colors, so the grilling techniques are also much more diverse than the way you grill meat.”

The guru behind the “Barbecue Bible” books and the host of “Project Fire” and other public-television series, Raichlen explores that diversity in his latest book, “How to Grill Vegetables.” He smokes chickpeas, connects asparagus spears with toothpicks to form rafts before grilling them and parboils cauliflower before spit-roasting it.

Unlike even lean meat, Raichlen points out, vegetables have no intrinsic fat, so they require the smart addition of it in the form of marinades and bastes. But they do caramelize over high heat; with vegetables, it’s the plant sugars rather than the proteins that transform.

“You’re getting umami flavors you just wouldn’t get by boiling or steaming,” he says. To me, one of the most appealing advantages vegetables have over meat on the grill is what Raichlen refers to as their “self-smoking architecture.”

“If you char a sweet potato in its skin or a pepper or an onion, you drive the smoke from the exterior of the skin to the center of the vegetable,” he says. That’s why, say, baba ghanouj and roasted red peppers have such extraordinary flavor.

The best way to take advantage of this architecture is by ember grilling, or putting the food directly on coals, turning it frequently to char it all over until the interior is tender. It might seem a little risky – using long-handled tongs and wearing grilling gloves is a must – but it’s actually pretty foolproof, especially when it comes to root vegetables such as sweet potatoes.

First, you let the coals die down until there’s no active flame, but they’re glowing and covered in white ash. You fan off some of the loose ashes, then sit the sweet potatoes on the coals and turn every few minutes until they are completely blackened all over, and then keep going until the insides are tender when you insert a metal skewer.

Brush them off and cut them open, then admire the gorgeous contrast between the black skin and the bright orange flesh (or another color, if you use pale or purple varieties) before digging into that delicious combination of smoke meets sweet. They’re good for so many uses at this point, but this recipe from Raichlen jazzes them up further with a lemony yogurt and the Egyptian spice/nut blend dukkah.

One of the most efficient ways to employ ember grilling is to do it in conjunction with your other uses of the grill. That is, put whatever else you want to grill on the grates while the fire it still hot, then add the sweet potatoes to the embers after the flames die down. You also can cook them on a gas grill by cranking it up as high as it will go, but IMHO, that would be missing the whole point.

Ember-Grilled Sweet Potatoes

Adapted from “How to Grill Vegetables” by Steven Raichlen (Workman Publishing, 2021).

For the dukkah

¼ cup whole raw hazelnuts

¼ cup whole raw almonds

¼ cup raw pumpkin seeds

¼ cup white sesame seeds

1 teaspoon freshly ground black pepper

1 teaspoon ground coriander

1 teaspoon ground cumin

½ teaspoon table or fine sea salt, plus more to taste

¼ teaspoon ground cinnamon

For the sweet potatoes

4 sweet potatoes (8 to 12 ounces each), scrubbed but not peeled)

For the lemon yogurt

½ cup plain or Greek-style yogurt (may substitute nondairy yogurt of your choice)

1 tablespoon chopped preserved lemon with 2 teaspoons preserved lemon juices (may substitute 1 teaspoon finely grated lemon zest, plus 1 tablespoon fresh lemon juice and salt to taste)

Make the dukkah: In a large, dry skillet over medium-high heat, combine the hazelnuts and almonds and toast until fragrant, 1 to 2 minutes. Add the pumpkin and sesame seeds, pepper, coriander, cumin, salt and cinnamon, and toast until the sesame seeds are lightly browned, about 1 minute. Transfer the mixture to a bowl and let cool.

Transfer the dukkah mixture to a food processor and grind to a coarse powder, being careful not to overprocess into a paste. Taste, and season with more salt, if needed.

Grill the sweet potatoes: Build a charcoal or wood fire in your grill, let it burn down to glowing coals, and rake them into an even layer. Fan them with a folded newspaper to dislodge any loose ash, then lay the sweet potatoes directly on the coals. Cook, turning every 5 minutes, until the flesh is tender when pierced with a skewer, 20 to 30 minutes or longer, depending on the potatoes’ thickness.

The skin will char long before the potatoes are tender. (Alternatively, you can grill the potatoes over medium-high heat for about the same amount of time, or over indirect heat for about twice as long, adding hardwood chunks to the coals or a smoker box if using a gas grill.)

Make the lemon yogurt: In a small bowl, whisk together the yogurt, preserved lemon and juices until combined. To serve, make a deep lengthwise cut in each sweet potato (you want to cut almost all the way through, but not through the skin on the bottom. Dollop or drizzle the lemon yogurt on each potato, sprinkle each with about 2 tablespoons of dukkah, and serve warm or at room temperature.