There are two ways to get guaranteed crispy sweet potato fries. In your oven (yes!) or in a deep fryer. Even deep frying plain sweet potato fries won't get them crispy. You need a tiny bit of the secret ingredient - cornstarch.

Right here, right now, I’m going to teach you how to make crispy sweet potato fries—despite the fact that they are not real fries. They are imposters, stand-ins, the understudies of the fry world, only to be eaten when a proper french fry is unavailable.
After years of testing (and disappointment), I’ve cracked the sweet potato code. Whether you deep fry them or bake them, these sweet potato fries will actually be crispy. Guaranteed.
But they're more guaranteed if you do them in the deep fryer.
Here's what you need to do to create this perfect sweet and spicy lunch or side dish.
Ingredients
- Sweet Potatoes
- Cornstarch
- Olive Oil




- Cut your sweet potatoes into fries. Let them soak in water.


2. Put a bit of cornstarch in a bag or bowl with a lid.
3. Shake the fries around in the cornstarch.


4. Lay the fries on a baking sheet.
5. Drizzle with olive oil.


6. Mix in the oil.
7. Separate fries on the pan and cook 'em.
10 years after posting this I'm still using the cheapest, most basic vegetable peeler around and it's pretty much every cook's favourite.
It's the Maybelline mascara of the vegetable peeling world. A reliable workhorse.
Table of Contents
Dipping Sauce

Meanwhile you can make the dipping sauce. Mix together ½ cup of mayonnaise with 1 teaspoon of Sriracha sauce and ¼ teaspoon of Cayenne Pepper.
You can adjust the proportions to taste. Mix it up and taste it then adjust as you like.
Saturated and Unsaturated Fats
Saturated Fats for frying
Would you like to save this stuff?
- Lard
- Tallow
Monounsaturated & Polyunsaturated Fats for frying
- Olive Oil
- Canola Oil
- Peanut Oil
- Sunflower Oil
You can use as much or any oil that you want.
(The more oil you use for oven baking the greater chance the fries will be crispy )
TIPS
- Cut the fries to about about ⅜ths of an inch. Bigger than that and they'll burn before they cook.
- Arrange them so they have space between each fry. The less of them on the pan the better they'll cook. Too many shoved together and they'll never get crispy. They'll just steam. So do NOT overcrowd the pan.
- Check them after 15 minutes, flip them over (you might have to use a spatula depending on how "non stick" your pan is) and return to the oven if necessary for another 5 minutes. The timing really depends on the size of your fry, the heat of your oven and how well your pan conducts heat.
- Do NOT use too much cornstarch. It will lead to heartache and raw, powdery tasting fries.
- A dark, metal baking sheet will give the best results but ...
- Sweet Potato Fries will get dark fast because of their high sugar content. Don't forget to flip and turn them or they'll burn.

Deep Frying
Cut the fries, soak them in water for at least an hour and coat them with cornstarch as with the above recipe.
Instead of baking, pre-heat the fryer and fry until crispy.
This is how I do them when I'm in a rush. They're always crispier than those from the oven, but far less healthy.
See? I'm a french fry professional.

Ingredients
- 2 large sweet potatoes
- 1 Tablespoon of cornstarch
- *Dipping Sauce*
- ½ cup mayonnaise
- ¼ tsp. cayenne pepper
- 1 teaspoon or more Sriracha sauce
Instructions
- Preheat oven to 425 or deep fryer to highest setting
- Peel sweet potatoes, slice into medium thick slices (closer to thin than thick).
- Soak potatoes at least 4 hours in water.
- Drain water from sweet potatoes and shake dry with your hands.
- Put 1 Tablespoon of cornstarch into food safe plastic bag.
- Dump sweet potato fries into bag, blow some air into it, and shake bag until fries are coated.
- Place fries on cookie sheet, drizzle with a couple Tablespoons of olive oil.
- Toss fries until evenly coated with oil.
- Arrange on cookie sheet(s) with lots of space in between fries to prevent steaming.
- Cook in hot oven for 15 minutes then check.
- The fries will release from the pan when they're ready to flip the same way a steak would.
- Flip fries, and continue to cook for another 5-10 minutes.
- (cooking time depends greatly on the quality of your baking sheet so keep an eye on them)
- Dipping Sauce: Mix together mayo, pepper and Sriracha sauce. Adjust to your taste.
Notes
- Do NOT use too much cornstarch. It will lead to heartache and raw, powdery tasting fries.
- A dark, metal baking sheet will give the best results.
- Sweet Potato Fries will get dark fast because of their high sugar content. Don't forget to flip and turn them.
Please note : This recipe does have a bit of a learning curve. It may take a few attempts to get your proportions of corn starch and oil correct. It took me several years to figure out how to do this, but with these instructions it shouldn't take you more than a couple of tries.
Now that I've run you through all of this and convinced you it's the way to cook sweet potato fries, I'm going to try a new experiment with blanching the sweet potatoes in water and THEN baking or frying them. I will keep you updated.
Or as we say in the sweet potato world - I'll keep you in the loop regarding the sweet potato scoop.

Ed Spencer
Got on to your site via Lee Valley. I like your attitude.
My winter breaker is Butternut Squash. I cut it in half lengthwise, scoop out the seeds ( if it's a good one save some seeds for Spring ) fill the hole with Brown Sugar, doesn't matter what kind, liberally inundate with cheap "maple syrup" Old Tyme is good, stab a few slits to allow the goop to infiltrate the rest of the squash and bake at 350 until you think it is done, nice and soft, scoop out the "meat" and blend with a knob of butter or your favourite transfat. Goes well with anything. DO NOT MIX WITH MARSHMALLOWS and other yucci goop. Put the skin in the compost. TSC already got seeds in, won't be long now.
mary sober
These looked so delicious that I admittedly was too impatient to soak for any amount of time as I had to leave shortly.... They still turned out amazing!!!! I love sweet potatoes but every time I have previously made fries they were dry or squishy. I did use a little more cornstarch than recommended , but they are crispy and yum!!!!!! Thanks
Karen
I'm glad they worked out for you mary! Did you try the dipping sauce? ~ karen
mary sober
I did! I just discovered Siracha 2 weeks ago, so this is genius. very yummy so yummy in fact I am having it again today. Only today I soak lol
Gabi
The title of this recipe desperately needs to be changed; you cannot claim to "guarantee" crispy sweet potato fries and then add a disclaimer at the end of the recipe to warn people that it may take many attempts to achieve the results this recipe originally "guaranteed." If the recipe and instructions are so specific and approaches need to be modified several times in order to be successful, the results you've achieved are clearly highly unattainable for most people reading through this recipe. Attacks on individuals who find this method unsuccessful and comment on it also seem unnecessary. I followed this recipe perfectly and I think my fries turned out soggier than they ever have before. Disappointing.
Karen
Hi Gabi! Very brave of you to comment. Tt is not a magic recipe. It is a recipe that needs to be followed. When it's followed, the fries are crispy. The results I've achieved are not clearly highly unattainable. ~ karen!
Kathy Salkeld Bonilla
Mine were perfect, made in a gas oven here in Vilcabamba, Ecuador, using an OLD pan! Thanks for the GREAT recipe! I made a garlicky, hot spicy dip with greek yogurt and homemade mayo, yum! I also make yucca fries which I love with garlic mayo...
Susan
I just found your blog yesterday. Found this recipe and laughed at all the comments and your replies! I laughed out loud at the "shove it" to the anonymous poster. Made the sweet potatoes tonight for dinner and they were pretty crispy. I know I could have gotten them crispier if I left them in a bit longer but I got impatient. I will make them again for sure.
And I totally remember you from your t.v. days! I'm glad I stumbled upon your website. Can't wait to look around some more!
Ginger
Even though this is a relatively older post, I wanted to put my 2 cents in! I always read comments before I try recipes and hope that this will help someone. I tried this recipe last night and it was a success!! I cut my potatoes pretty close to what you have pictured and rinsed them twice before soaking for about 4 hours. I then drained the water and left the potatoes in the bowl until I was ready to fry them. I put some potatoes in a zip bag and sprinkled some cornstarch in there and shook it around. Then I fried my potatoes in vegetable oil in my fryer set at 400 degrees for 3 1/2 minutes per batch. They were perfect! Even my sweet potato-hating hubby said they were great!!
Karen
So ... you followed the instructions. ;) That really is the issue most people have even though they don't realize it. They shorten or just plain skip some of the steps. Glad they worked for you and I hope you made the sauce! ~ karen
Shauna
Darn, I've tried twice to make these, because they look so amazing. Both times they stick like crazy to the pan and they don't get crispy. So sad. I wonder if they don't work at altitude, I'm at 7500ft. I'm going to try coconut oil next time, and maybe cooking them on a rack instead of on a plain flat pan. :-(
Karen
Hi Shauna! If they're sticking like crazy it sounds like your pan isn't cooperating. I'm guessing it's a fairly light coloured pan? Try using more oil. I would continue to use olive oil if you can. And don't try to turn them until they're good and brown. Kind of like a steak, that will release from a grill once it's been browned, so will the fries. The other thing you can do is go to a secondhand store and get an old, used cookie sheet. One that's nice and dark. They are great for browning things and having great non stick properties after all the years of baking on them. :) ~ karen!
Shauna
It's a dark old pan. Thank you, Karen. I'll try more oil and holding off on turning them.
rida ali
can i make these in a toaster oven?
Karen
I've never tried Rida, but I don't see why not! ~ karen
judy
Once again I have to say you have amazing advice and ideas. You are not only a french fry professional, you are a genius.
Jennifer Harris
After many years of trying to make CRISPY sweet potatoe fries in the oven, I finally ran across your recipe. Hoorah! They came out SO CRISPY and yummy. I did add a little sprinkle of dried rosemary, seasoning salt, garlic powder, lemon pepper and paprika on them right before I put them in the oven. They were delicious!!! I used some yogurt, a little mayo and Grey Poupon to dip them in> Any spices the cook fancies can be used, of course, but what a treat not to have soggy and some burned. Thank you, keep up the good work!
Limeyjen
Christine
I will try this recipe but felt the need to address the "stupid meal plan" comment. I have spent almost three months in hospital and have developed IBS after bowel surgery. Sweet potato is one of the few vegetables that doesn't trigger gut/bowel issues for me. Stupid meal plan or making the best of things? There are many people out there who rely on different foods to sustain themselves in a healthy way - so please reflect on this before labelling it as a stupid meal plan
Karen
Christine. I think you're taking that sentence a little too personally. ~ karen
Khaili
Baked these last night in the oven. So amazing! Totally crunchy! Thank you!!!
uraina
Karen, cornstarch was the best secret I discovered a few years back for SP fries. I season my cornstarch though with Kosher salt, cayenne pepper, chili powder, and garlic powder. When they're done I give them a sprinkle of Old Bay seasoning, A-MAZ-ING! I have never soaked them in water though, I will try that next time to see if I can tell the difference. Also, that dipping sauce sounds amazing, will have to try that as well.
Thanks.
Kristal
Sweet potato fries are one of my all time favorites, this recipe looks good!
Karen
Let me know how it works out for you Kristal. Good luck. :) ~ karen!
Naomi
This is the first time I made them. I used our home grown sweet potatoes! Not to bad my hubby like them too! I think I will use less cornstarch next time.
Thanks for all the time you put into making the recipe work!
ladyrose
Just made these for dinner. We did the deep fry method. Worked perfectly!! We are very happy little sweet potato fry consumers now. Btw, we always serve ours w/ a little shot glass of maple syrup for dipping. Yummy!!!
Karen
Glad they worked out well for you ladyrose! I always laugh when people use something sweet to dip their sweet potatoes in. I make my sauce as hot as possible to cut the sweet. Something most of my family members are appalled by. ~ karen!
Elin
Made these tonight for the first time and they turned out perfect!!!! Fantastic recipe! Thanks for sharing!
Karen
Thanks for letting me know Elin! ~ karen
Keli
A-MAZ-ING. I'm a few years behind the crowd here, but thank you for the great recipe. My pan wasn't non-stick so I coated it with oil - the fries still stuck a bit (so I jumped on Amazon and ordered a non-stick cookie sheet because we MUST have these again!). They were delicious. I assume they were meant to be salted at the end (because what's a fry without salt?).
I'm not much of a spice girl, so I cut down on the Siracha. Used 2/3 greek yogurt and 1/3 mayo - added a few shakes of garlic salt to make up for it. Delicious.
Served with a huge green salad for a delicious veggie meal. Will make these again and again.
Karen
Excellent Keli! Also remember the longer you use a non stick cookie sheet and the darker it gets (from cooking on it in the oven) the better it will be. So don't be disappointed if it isn't great at first. That's just the way they are. ~ karen!
mila furman
Karen I am drawn to your blog not only because of the gorgeous pictures but because I have a culinary background as well as I prefer to do most things the scientific route! So I bet this will do juuuuust fine :)
mila furman
Karen so glad to have found your blog!!! I never would have thought to do this!! Love it! Pinned and definitely trying it out!
Karen
Hi Mila. Welcome to The Art of Doing Stuff! As you can see there's varied results with this recipe, lol. But if you follow my instructions you'll do fine. And don't forget to make the dip! ~ karen!