Roasted Sweet Potatoes

If weeknight cooking were a rom-com, roasted sweet potatoes would be the best friend. Whether you’re prepping a quick salad, building an epic burrito bowl, or simply looking for an easy side, they’re always there for you and will never let you down. Learn the ultimate technique for making them, and you’ll call on their support at least once a week.

While vegetables such as broccoli and zucchini are best cooked at immediate high heat on an uncovered baking sheet, sweet potatoes reach roasted perfection by starting out in a cold oven on a covered baking sheet. They finish roasting uncovered at high heat to achieve that perfect caramelization.

How To Make Roasted Sweet Potatoes

Achieving amazing roasted sweet potatoes is not difficult, but the process is probably different than you might expect. It all comes down to maltose, a type of sugar that’s created from the starches in the sweet potatoes as they roast. According to food scientist Harold McGee, maltose is created when an enzyme within the sweet potato becomes activated at around 135°. The enzyme will continue to convert the starches in the sweet potato into maltose until it becomes deactivated at 170°. The longer the sweet potato’s temperature stays within that 135° to 170° range, the sweeter and more flavorful the roasted sweet potato will become.

Starting the sweet potatoes in a cold oven gives them maximum time in this desired temperature range. At the same time, keeping them covered during this first stage of cooking locks their moisture in, preventing them from drying out and shriveling. Once the sweet potatoes have cooked through and the oven is thoroughly heated, uncovering the sweet potatoes allows them to caramelize on the baking sheet.

That’s the science behind why we’re doing what we’re doing. Now let’s break it down step by step.

INGREDIENTS

• Sweet Potatoes: Standard orange sweet potatoes are ideal for this recipe. You can also use yams if you like, which typically have a wider circumference. Regardless, make sure to cut the sweet potatoes into even cubes so they cook as evenly as possible.
• Neutral Oil: An oil with a high-smoke point is ideal for this high-temp roasting. Vegetable oil is my go-to, but grapeseed or canola would work too.
• Kosher Salt: I test all my recipes with Diamond Crystal kosher salt. If you’re using table salt or Morton kosher, I recommend using half the amount called for in the recipe.
• Black Pepper: Always use freshly ground!

STEP-BY-STEP INSTRUCTIONS

Start by cutting the sweet potatoes into 1/2" cubes. You can peel them if you like, but you don’t have to: The skins contain valuable nutrients and extra fiber, and I actually enjoy their texture, so I typically leave them on. Toss the cubed sweet potatoes in a bowl with neutral oil, kosher salt, and (always!) freshly ground black pepper.

Spread onto a medium rimmed baking sheet and cover tightly with foil, crimping the edges around the rim of the baking sheet to seal.

Arrange an oven rack in the middle of the oven and place the sealed baking sheet on it. Then set the oven temperature to 450° and set a timer for 20 minutes. (During that 20 minutes of initial cooking, the oven will probably beep, indicating that it’s heated to the right temperature; ignore it.) After 20 minutes, remove the foil from the sheet pan. Continue to roast the sweet potatoes until browned on the bottom and totally tender, about 10 minutes more. Let the sweet potatoes cool for at least 5 minutes on the sheet pan before serving.

Full list of ingredients and directions can be found in the recipe below.

Recipe Tips

• The position of your oven rack really matters here. For best results and most even cooking, make sure it’s in the center of the oven.
• After the foil comes off, the rate at which the sweet potatoes brown really depends on the color of the sheet pan. If your sheet pan is dark, watch them closely after the first five minutes so they don’t get too dark.
• If you want slightly larger chunks of sweet potatoes, feel free to cut the sweet potatoes into 3/4" cubes. I tested this recipe with both 1/2" and 3/4" cubes and found that, while both sizes cooked through and caramelized well in the time, the 3/4" cubes weren’t as versatile. (They were too big to use in a salad or a burrito.) That said, if you’re making this for a simple side and want them to have a little more presence on the plate, feel free to try this heftier cut!

Storage

Roasted sweet potatoes will keep in an airtight container in the refrigerator for up to 5 days. If you want to freeze them, they will stay good for up to 1 month.