The Best Mashed Sweet Potatoes Recipe (2024)

Why It Works

  • Browning butter packs in tons of flavor, without dulling the sweet potatoes.
  • Slow-roasting the sweet potatoes activates endogenous enzymes that bring out their natural sweetness.
  • A touch of maple syrup, butter, and a bit of chopped thyme are the only embellishments these naturally sweet sweet potatoes need.

Have you ever wondered why sweet potatoes are so darn insecure? They come to the table hidden under a blanket of marshmallows or a sticky-sweet layer of sugary syrup. You eat them and taste only cinnamon and nutmeg, the natural aroma of the sweet potato buried underneath layers of spices. I often feel like sweet potatoes are that friend who you just want to sit down to tell them they don'tneedall that makeup or fussy fashion to be at their best.

Poke around and you'll find recipes forstreusel-topped casserolesthat look more like dessert. You'll findrecipes that call for a whopping full cup of sugar. You'll bump into dishes thathide behind a mask of cream and butter. What youwon'tfind much of is a real, testing-based approach to making mashed sweet potatoes in a way that brings out the best in them, with minimal extra ingredients and a bit of good technique.

It's time to say good-bye to the days of hiding sweet potatoes behind sugar and bolted-on marshmallows. What we have here is a technique for making mashed sweet potatoes that are so sweet, rich, and packed with sweet-potato flavor, they need only the simplest of embellishments to shine.

The Science of Sweet: Converting Starches Into Sugars

Sweet potatoes, like a few other starchy tubers and gourds, have a secret hero superpower locked within them. By unlocking that superpower, you can actually make a sweet potato taste sweeter without adding any extra sugar to it. I've talked through some of this science in the past, inan article about the best roasted sweet potatoes, but it's worth a recap, as it all applies here as well:

Here's the deal: Starch is made from sugar. More precisely, starch is a polysaccharide, which means that it's a large molecule consisting of many smaller sugar molecules (in this case, glucose). The thing about sugar is that unless it's broken down to relatively simple forms, it doesn't taste sweet to us. Our tongue simply doesn't recognize it.
It helps to imagine sugar molecules as a bunch of cartoon kids. When they're all standing in a row, it's easy for us to identify them as individual kids. But stack them up on each other and throw a trench coat on 'em, and they're effectively hidden.
Now, sweet potatoes contain plenty of starch molecules. The goal when roasting them is to try to break down as many of the starch molecules as possible into sweet-tasting maltose (a sugar consisting of two glucose molecules). Pull off the trench coat and give that little stack of kids a push, if you will. We do this with the help of enzymes.


AsHarold McGeewrites inOn Food and Cooking:

"Moist sweet potato varieties sweeten during cooking thanks to the action of an enzyme that attacks starch and breaks it down. The enzyme starts to make maltose when the tightly packed starch granules absorb moisture and expand, beginning at around 135°F, and it stops when the rising heat denatures it, at around 170°F."


You see where we're going here? By holding a sweet potato in that, ahem,sweetspot between 135 and 170°F (57 and 77°C) for an extended period of time, you can actually induce it to naturally convert its starches into sugars.

To test this, I started with a half dozen sweet potatoes. I cut each one into quarters and left one of those quarters carefully wrapped in the refrigerator. The other three I encased in vacuum-sealed bags andheld in a water bathset to 145°F (63°C) for one hour, six hours, and 24 hours, respectively.* After that, I roasted them with a bit of olive oil in a hot oven until they were tender.

*For the record, most vegetables will never soften at 145°F, as pectin, the main structural compound in a vegetable's cell wall, doesn't break down until above 180°F (82°C) or so. The sous vide sweet potato quarters were still as hard-feeling as their refrigerated counterparts.

The Best Mashed Sweet Potatoes Recipe (1)

There's a direct correlation between how sweet the potatoes taste, how well they brown, and how long they've been held at 145°F. Though the sous vide potatoes actually seemed to lose a little pigment (the flesh was not as bright orange as in the refrigerated potatoes), the flavor difference was immediately apparent. A little more testing revealed that the most prominent effects occur within the first couple of hours. Any extra time the potatoes spend in the bath is incremental.

If you've got yourself agood sous vide rig, then the process here is simple: Throw your whole sweet potatoes directly into a 145°F water bath, let them rest for a few hours, then roast and mash them. If you're hell-bent on the absolute best sweet potatoes and don't have a sous vide circulator, you can easily use the beer cooler method. Just fill a cooler with water at around 170°F, add your sweet potatoes whole, put the lid on, and let them sit for a couple of hours before packing them in foil pouches and roasting for the recipe. But I wanted a method that would take advantage of this phenomenon without the need for any fancy equipment. I turned to the oven instead.

Slow-Roast for the Most Maltose

An oven is not as precisely controlled as a sous vide water bath, but I figured that with a low enough temperature, I should be able to give the potatoes a good long stay in that 135-to-170 sweet spot. Roasting potatoes at 300°F (150°C) for a couple of hours was certainly an improvement over the more standard hour in a 375°F (190°C) oven, but it still wasn't ideal—the exteriors of the potatoes just got too hot too fast.

Much better was to wrap the potatoes in a tightly sealed foil pouch. This traps in any escaping moisture, which prevents the outer layers of the potatoes from overheating as they roast. You end up with more evenly cooked and, more importantly,sweetersweet potatoes that are incredibly easy to peel. By placing the potatoes directly in a cool oven and allowing them to heat as the oven preheats, you can also enhance their enzymatic sweetening.

The foil-pouch method also allows you to add aromatics as you're roasting. A few sprigs of thyme makes for a classic pairing.

Brown Is Better: Browned Butter Adds Richness and Complexity

The Best Mashed Sweet Potatoes Recipe (2)

With perfectly sweet, tender, and easy-to-peel sweet potatoes, all that was left was a bit of fine-tuning. Thanksgiving is not the time to be shy with the butter, and there was no doubt that these potatoes would be getting some. I'd brought an early test batch over to a friend's place for an early Thanksgiving meal (we do alotof early Thanksgivings 'round here), and he commented on the sweet potatoes, asking if they contained any brown butter.

Nope, but by gum, that's a fantastic idea! The potatoes themselves get a rich, almost toffee-like complexity due to the slow roasting. Adding butter that's been cooked down until its milk solids just begin to turn brown and nutty accentuates that flavor even more.

Some folks like to add cinnamon, nutmeg, or other spices to their sweet potatoes. My theory is that they're just overcompensating for sweet potatoes cooked in a way that doesn't bring out their best flavor. We don't have that problem here. The only other additions I made before whipping them up were some salt, a little fresh thyme to complement the sprigs that I'd placed in their foil pouches, and a small dash of maple syrup to accentuate that caramel flavor even more.

What you end up with is rich and complex, with a natural built-in sweetness that is far more complex and satisfying than anything that extra sugar or a marshmallow topping could ever get you. These are sweet potatoes for true sweet-potato lovers.

The Best Mashed Sweet Potatoes Recipe (3)

November 2014

Recipe Details

The Best Mashed Sweet Potatoes

Prep15 mins

Cook2 hrs

Total2 hrs 15 mins

Serves8to 10 servings

Makes6 cups

Ingredients

  • 4 pounds (1.8kg) moist sweet potatoes, such as ruby or garnet yams (about 4 large potatoes; see notes)

  • 8 sprigsthyme, divided

  • 6 tablespoons butter (3 ounces; 85g)

  • 1/4 cup (60ml)maple syrup

  • Kosher salt

Directions

  1. Adjust oven rack to center position. Place 2 large sheets of heavy-duty aluminum foil on a work surface. Working with 1 sheet at a time, place half of potatoes in center along with 3 sprigs of thyme. Fold up foil and crimp edges to seal tightly. Repeat with other half of potatoes. Transfer pouches to a rimmed baking sheet and place in oven. Set oven to 300°F (150°C). Roast until a thin skewer inserted into potatoes meets no resistance, about 2 hours. Remove potatoes from oven and set aside until cool enough to handle.

  2. Meanwhile, melt butter in a medium saucepan over medium-low heat, swirling gently, until particles are pale golden brown and smell nutty. Immediately transfer to a large bowl or the bowl of a stand mixer fitted with a whisk attachment. Add maple syrup. Pick leaves off of remaining 2 thyme sprigs, roughly chop, and add to bowl.

  3. Peel sweet potatoes and discard skins. Add flesh to bowl with butter and syrup. Beat with whisk attachment or a handheld mixer until smooth and fluffy, about 2 minutes. Season to taste with salt. Serve. See note for make-ahead suggestions.

    The Best Mashed Sweet Potatoes Recipe (4)

    The Best Mashed Sweet Potatoes Recipe (5)

Special Equipment

Rimmed baking sheet, handheld electric mixer or stand mixer

Notes

Sweet potatoes can be made even sweeter by pretreating them in a water bath to activate their enzymes. To do this with a sous vide–style circulator, set your circulator for 150°F (66°C). Place the sweet potatoes in the water bath and let circulate for 2 to 4 hours before proceeding with the recipe. To do this with a beer cooler, fill your cooler with water at 170 to 175°F (77 to 79°C). Add the potatoes, cover, and let rest for 2 to 4 hours before proceeding.

Make-Ahead and Storage

Sweet potatoes can be refrigerated for up to 5 days. To store and reheat, transfer the sweet potatoes to a heavy-duty zipper-lock bag with the air pressed out. Reheat by completely submerging the zipper-lock bag in a pot full of hot (not boiling) water, removing the bag occasionally to squeeze contents around, until fully reheated, about 30 minutes. The best way to do this is with a sous vide–style circulator set at 150°F.

The Best Mashed Sweet Potatoes Recipe (2024)

FAQs

What brings out the flavor of sweet potatoes? ›

Slow-roasting the sweet potatoes activates endogenous enzymes that bring out their natural sweetness.

What are the tips and tricks of sweet potatoes? ›

Selection and storage tips: Choose firm, small- to medium-sized potatoes with smooth skin. Avoid cracks, soft spots and blemishes. Choose sweet potatoes with a bright, uniform color. Store them in a cool, dark, dry place for use within two to three weeks or at room temperature for up to a week.

How do you make mashed sweet potatoes less watery? ›

Besides flour added to thicken mash potatoes that you have gotten too thin, you can add some instant potatoes. This is what I would do. I also add instant potatoes to thicken soup when it is too 'runny' for my taste. Not a lot, a little will do it very nicely.

How do you make Ina Garten mashed sweet potatoes? ›

Place the sweet potato meat into the bowl of an electric mixer fitted with a paddle attachment and add the orange juice, cream, butter, brown sugar, nutmeg, cinnamon, salt, and pepper. Mix together until combined but not smooth and transfer to a baking dish. Bake the potatoes for 20 to 30 minutes, until heated through.

Why do you need to soak sweet potatoes before cooking? ›

TIPS & TRICKS to Make this Recipe: The main secrets to achieving that incredible crispy texture, is to soak the cut sweet potatoes in cold water for at least 30 minutes. This helps remove the starch from the sweet potatoes so they´re not limp & soggy.

Why not to boil sweet potatoes? ›

Despite their sweet taste, these potatoes have an intermediate glycemic index (GI) level, meaning they are digested and absorbed fairly slowly, leading to a more gradual increase in blood sugar levels. But, a lot of these benefits, including nutrients and taste, can be lost by boiling sweet potatoes.

How long to boil sweet potato? ›

Boil sweet potatoes for 15 to 20 minutes, until they are tender when pierced with a fork. It will take less time if you cut the sweet potatoes into smaller pieces. Drain and return to the pot.

What is the most nutritious way to cook sweet potatoes? ›

Boiling sweet potatoes retains more beta-carotene and makes the nutrient more absorbable than other cooking methods such as baking or frying. Up to 92% of the nutrient can be retained by limiting the cook time, such as boiling in a pot with a tightly covered lid for 20 minutes.

How do I make my sweet potato mash thicker? ›

You can use what you have on hand: Flour, cornstarch, or powdered milk are all solid options that are probably already in your pantry. Potato flour and potato starch would work as well. Stir in the thickening agent gradually, about a tablespoon at a time, until the potatoes have reached your desired consistency.

Why are my mashed sweet potatoes watery? ›

How Do I Make Sure My Mashed Sweet Potatoes are Not Watery? To make sure your potatoes aren't watery, don't overcook the potatoes. It's also important to drain the potatoes completely once you're done boiling them to avoid having unwanted water lingering in your pot.

Why did my mashed potatoes turn out sweet? ›

Is there anything I can do with them so I don't taste that sweet flavor? A: Someone told you correctly! When potatoes are stored too long, in a too-cold environment (below 41°F) the starches within convert to sugar.

How to cook sweet potatoes Martha Stewart? ›

Scrub and pat potatoes dry. Pierce potatoes all over with the tines of a fork and bake in oven, directly on rack, until soft and caramelizing, 1 1/2 hours. Slash the tops of potatoes open with the tip of a sharp knife and push ends of each potato toward each other to open.

Is it better to boil sweet potatoes or bake sweet potatoes? ›

Baking can also cause an 80% drop in vitamin A levels, twice as much as boiling. Therefore, from a nutritional standpoint, boiling rather than baking should be recommended for cooking sweet potato.

Should I peel sweet potatoes before boiling? ›

Do I Need to Peel Before Boiling? You do not need to peel sweet potatoes before boiling. If leaving the peel on, you will need to pierce the skin of the potato with a fork a few times. Also, boiling a sweet potato with the peel will require slightly more time for it to cook through.

What does baking soda do to sweet potatoes? ›

Baking Soda – boiling the potatoes in baking soda draws out the starch and allows the outside to get brown and crispy. Sweet Potatoes – yams work fine too. Extra Virgin Olive Oil – gets infused with rosemary and garlic and is the key to getting that crispy exterior.

What tastes good on a sweet potato? ›

TOPPING OPTIONS:
  • Brown sugar, cinnamon, butter and salt.
  • Maple syrup, butter and toasted pecans.
  • Sour cream, chives, salt and pepper.
  • Blue cheese, walnuts and honey.
  • Mini marshmallows, brown sugar and cinnamon (pop it under the broiler to toast the marshmallows a bit)
  • Beef, Turkey or Veggie Chili.
  • Sloppy Joe meat.
Jan 3, 2019

What flavors go best with sweet potato? ›

That's why we've served up a number of ways to give your sweet potatoes a welcome flavor boost.
  • Sweeten with brown sugar and pecans. ...
  • Caramelize with maple syrup. ...
  • Stuff with pesto. ...
  • Provide a creamy touch with goddess dressing. ...
  • Top with honey and bacon. ...
  • Smear with manouri and honey. ...
  • Add spinach and melted feta.
Feb 17, 2023

What is the best flavored sweet potato? ›

The Satsuma-Imo is an impressive potato with vibrant purple skin and a yellowish flesh that darkens as it is cooked. They are perfect when baked, roasted or steamed because of how the Satsuma-Imo retains sweetness and a delicious chestnut flavor.

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