When I’m hungry and don’t know what to make for dinner, I reach for a lone potato of just about any kind. As a result, I’ve experimented with all sorts of baking temperatures and methods when it comes to cooking potatoes of all shapes and sizes—not just as a recipe developer and a food writer, but as a home cook who finds herself stumped at what to make for dinner just like anybody else.
I’ve peeled and boiled them, cut them into slivers to bake like steak fries, and I’ve popped potatoes in the microwave until they’re tender and hot—no problem. But more often than not I prick them with a fork and place them in a standard 350 degree F oven right on the rack. Historically, it has been the most reliable for me, a method that works whether I’m going the savory jacket potato route or craving something sweet.
But I recently learned that when it comes to Thanksgiving’s darling, the sweet potato, I might be doing it all wrong. Here’s what I learned about roasting sweet potatoes low and slow, and what I’m keeping it in mind as I kick into gear for Thanksgiving prep.
The Best Way To Cook Sweet Potatoes
Not only does cooking sweet potatoes low and slow allow you some time to do other things in the kitchen—or simply sit back and relax—it makes them taste better too.
The low-and-slow method helps with even cooking. Encased in the un-pricked, seasoned potato skin, the moisture moves throughout the fibers of the sweet potato evenly in a convective way.It keeps more moisture in, which amplifies flavor. As with any vegetable, roasting it at a low temperature retains more moisture in it for longer, pulling the most flavor out of it the interior it cooks. Sweet potatoes that are cooked low and slow will be softer, flavorful, and even sweeter as a result.It’s primed for crispy skin. Sweet potato skin can get gummy or soggy—but roasting it low and slow helps steam escape over time. Broiling it at the end helps with any residual moisture for a snappy, crispy, even charred or caramelized skin for extra flavor.
Creator @healthyemmie shares the way that different roasting temperatures change how the interior starch cooks. For temperatures between 300 and 325 degrees F, she shows how the texture can range from crystallized and honey-like to sticky and sweet. Note: @healthyemmie is using a Japanese sweet potato, which has slightly less starch than yam sweet potato, which has the orange interior more closely associated with Thanksgiving sweet potato casserole.
Similarly, Deb Perelman of smitten kitchen shares her method of cooking sweet potatoes low and slow, which calls for a 275 degree F oven, ample seasoning, and a quick hit of high heat under the broiler to emulate open-fire cooking. “The flesh of the sweet potato gets sweeter, louder, and more nuanced than seems possible,” says Perelman, “and the salty, lightly blackened skin gets so crispy, you’re going to immediately retroactively resent all of the sweet potatoes you had before then for not tasting like this.”
How To Slow Roast Sweet Potatoes
Inspired by Perelman, @healthyemmie, and my own research in the kitchen, I captured the best slow-roasted sweet potato recipe.
Season potatoes. Coat sweet potatoes potatoes in olive oil, then season them with salt, pepper, and any other spices of choice (I like to use cumin for a nutty, savory note). Place them on a baking sheet lined with aluminum foil.Slow-roast over low heat. Roast potatoes at 300 degrees F until it is soft and the bottom part has started to brown, about 2 hours to 2 1/2 hours, depending on the size of the potato. (I’ve found that a 300 degree F oven is the best baseline temperature to use across different types of sweet potatoes—with different starch and moisture levels—for about the same amount of time.)Broil. Once the sweet potatoes are soft and cooked through, broil them over HIGH heat until the tops are browned and toasted, about 3 to 5 minutes.
If you’re in a time crunch, you can absolutely roast sweet potatoes whole at 400 degrees F for a fraction of that time–just note that they may not retain as much of the sweet, complex flavors that slow-roasting would offer.
Dining and Cooking