Guaranteed Crispy Sweet Potato Fries & Sriracha Mayo Dip

Right here, right now I am going to teach you how to make crispy sweet potato fries. But first …

Let’s get one thing straight.  A sweet potato french fry is not a real french fry.  I like them, I’ll eat them … but they’re not a real french fry.

They are french fry substitutes to be eaten when a real french fry can’t be found.

Yes, I know.  But you loveeeeeeeee sweet potato french fries.  You like them wayyyyyyyyyy better than regular french fries.  That’s because you’re an amateur.   I on the other hand, am a french fry professional.

I have been eating, making and lusting after french fries for as long as I can remember.  I ate french fries every single day for lunch while I was in  highschool.  Large fries with gravy please. At the end of grade 13 … yes we had grade 13 back then … I threw up a ball of grease.  So … clearly … a professional here.

Best way to eat a french fry?  Salty and hot with your fingers, while walking around a flea market.  Using one of those wooden forks is pretty good too.  Best potato to make a french fry with?  A baking potato like the Russet or Idaho because the high level of starch makes them relatively dry and therefore easier to get crispy.  Best outfit for eating french fries?   Shorts, flip flops and a tank top.  So … clearly … again … a french fry professional here.

But … if you’re on some sort of stupid meal plan, or you’re all out of regular potatoes, or you just feel like having something a little different, why wouldn’t you cook up some Sweet Potato French Fries?

Because they’re soggy messes.  That’s why.

I’ve oven baked them, par boiled them and deep fried them and they don’t get crispy.  They get brown, but not crisp.

Finally, I’ve figured out how to make crispy sweet potato fries and the best part is you can do them in the deep fryer or the oven!  Either way, you’ll end up with crispy fries.  Guaranteed.

But like with most things, you’re more guaranteed if you do them in the deep fryer.

Here’s what you need to do …

Gather your sweet potatoes.


Get some corn starch.

Also get some olive oil. Just the cheap stuff.  Not the good stuff like my favourite Lorenzo No.5. Seriously best tasting olive oil ever.

Peel your sweet potatoes.  I have used the same brand of vegetable peeler for 15 years now.  It’s the cheapest, most basic vegetable peeler around and it’s pretty much every cook’s favourite.  It’s the Great Lash mascara of the vegetable peeling world.

Cut your sweet potatoes until they’re a medium thickness.  Not hugely thick cut and not shoestring.

Let potatoes soak in water for an hour – half the day.  (not mandatory, but recommended)

Preheat oven to 425°

Throw a Tablespoon or two of cornstarch into a plastic bag.

(update:  I’m reducing this to a definite 1 Tablespoon of cornstarch because people were reading this as 1 to 2 to 173 Tablespoons of cornstarch.  So it’s a hard 1 Tablespoon now.  Got it?)

Dump a handful of sweet potatoes into the bag with the cornstarch.  You don’t need to dry them with paper towels or anything.  Just drain the water and then give each handful you drop in the cornstarch a good shake.  Twist the top of the bag so it forms a balloon with some air inside and shake the fries around until they’re lightly coated with the cornstarch.  This is important.  Too much water and too much cornstarch and you’ll end up with a goopy mess.  Plus your fries will taste like cornstarch.

Put your coated fries on a non stick cookie sheet.

Drizzle 2 Tbsps. of olive oil over the fries. This is if you want to be healthy.

Any vegetable oil will work.  I’ve used sunflower, canola, etc. etc.

You can use as much oil as you want.

(Update: The more oil you use the easier time you’ll have of getting the fries crispy but the less healthy they will be.)

I usually go the totally unhealthy route to ensure the fries are crispy. Just keep glugging the oil until the fries are well coated.

Using your hands, make sure the fries are well coated.

Arrange them on the sheet again, so they have space between each fry.  The less fries 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.  Pop the fries into your preheated oven and cook for 15 minutes.

Meanwhile you can make the dipping sauce.  Mix together 1/2 cup of mayonaise with 1 teaspoon of Sriracha sauce and 1/4 teaspoon of Cayenne Pepper.

You can adjust the proportions to taste.  Mix it up and taste it then adjust as you like.

Check the fries 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.

(update:  You can see the pan I’m using here is very dark, this very dark, old, used pan cooks things faster and crispier. So if you have an old pan like this use it.  If you have a shiny, new baking sheet your fries will take much longer to cook, will have a greater tendency to stick and won’t get as crispy)


Yes. Guaranteed. Crispy. Sweet Potato Fries. There's one secret ingredient (corn starch, so not so secret) and a few tips and techniques that you have to follow. But if you do, it'll work and no more soggy sweet potato fries.

Maxwell Williams French Fry and dipping cup!!

If you prefer your fries deep fried, throw them in the deep fryer at the highest setting for a few minutes instead of sticking them in the oven. You STILL need to coat them in cornstarch.  Even in a deep fryer, sweet potatoes fries won’t get crispy unless they have a coating of cornstarch.

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? French fry professional.

0 from 0 votes
Guaranteed Crispy Sweet Potato Fries & Sriracha Mayo Dip
Author: The Art of Doing Stuff
  • 2 large sweet potatoes
  • 1 Tablespoon of cornstarch
  • *Dipping Sauce*
  • 1/2 cup mayonnaise
  • 1/4 tsp. cayenne pepper
  • 1 tsp or more Sriracha sauce
  1. Preheat oven to 425 or deep fryer to highest setting
  2. Peel sweet potatoes, slice into medium thick slices (closer to thin than thick).
  3. Soak potatoes at least 4 hours in water.
  4. Drain water from sweet potatoes and shake dry with your hands.
  5. Put 1 Tablespoon of cornstarch into food safe plastic bag.
  6. Dump sweet potato fries into bag, blow some air into it, and shake bag until fries are coated.
  7. Place fries on cookie sheet, drizzle with a couple Tablespoons of olive oil.
  8. Toss fries until evenly coated with oil.
  9. Arrange on cookie sheet(s) with lots of space in between fries to prevent steaming.
  10. Cook in hot oven for 15 minutes then check.
  11. The fries will release from the pan when they're ready to flip the same way a steak would.
  12. Flip fries, and continue to cook for another 5-10 minutes.
  13. (cooking time depends greatly on the quality of your baking sheet so keep an eye on them)
  14. Dipping Sauce: Mix together mayo, pepper and Sriracha sauce. Adjust to your taste.


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.

If it doesn’t work for you, it’s not the recipe it’s either a) your technique or b) your baking pan so try again.  You’ll get it. ~ karen


  1. Renee says:

    You are a genius. Just bought some sweet potatoes and will have to try this.

    Question: I like Sriracha sauce but I get migraines from MSG. I can usually handle a little bit (honestly, you don’t need much of the stuff), but was wondering… Does an acceptable alternative exist?

  2. fifi says:

    From one french fry lover to another – the very best french fries you will ever eat will be made in a chip truck under the Bluewater Bridge in Sarnia, ON. Just sayin…

  3. BCBev says:

    I bow down.

  4. Karen says:

    Renee – There really isn’t anything around that tastes like genuine Rooster brand Sriracha sauce. It doesn’t contain MSG by the way, it contains Benzoic Acid. However, if you think you’ll still have a problem with it, you can try any hot sauce. Franks Red Hot, Melinda’s, even Tobasco. Like I said, Sriracha has a definite taste to it (delicious) but if you experiment with your own hot sauces I think you’ll be able to come up with something you like! Also I toned down the amount of Sriracha for this recipe to make it more compatible to the most amount of palates. I actually use around 2 teaspoons. ~ karen

  5. Renee says:

    Hm, seems like I have already answered my own question. After some quick research, I found this sriracha sauce that has no MSG…
    “Roland Sriracha Chili Sauce”

    Anyone tried it?

  6. Renee says:

    Thanks for the reply! I did find one online that has no MSG (I thought Rooster sauce did, glad to hear it may not) – posted link below. Hard to believe it will taste as good, though 🙂

    I’ll definitely use the heavier dose when I make this!

  7. sk says:

    mmm sriracha mayo…
    or anything with sriracha…

    the oatmeal says it best:

  8. Bev says:

    I have just done my meal plan for this week, so I will have to go back and re-jig it to try and fit in the SP fries… Man I really want some now!

    We get different sorts of SP or ‘Kumera’ in NZ, the orangey ones like you’ve used and yellow ones that seem less sweet. Can I use either?

  9. Jennifer says:

    Ah — corn starch?! Thanks for letting us in on your secret. Can’t wait to try — they look picture-perfectly delish. (Btw, your site’s loading much faster now. Whatever you did to tweak it worked.)

  10. Karen says:

    Hey Bev – I’ve never used the yellow ones but I can’t imagine it wouldn’t work. There’s no reason for it not to. Give it a shot and let us know! ~ karen

  11. Michelle says:

    I love the french fry tips! Thank you! But what I REALLY want to know: where did you get the cool french fry and matching dip bowls? LOVE THEM!!

  12. Karen says:

    Huh! I’m going to continue tweeking. I’m not sure what else to do! The quicker loading time also has to do w/ the number of pics. in a post and the time of day. Fingers crossed it gets even better. ~ karen

  13. Karen says:

    Michelle – Here you go … somewhere in the comments section there’s a link to buy them on Amazon!

  14. Angela says:

    So glad that I’m not the only one who chooses regular fries over SP fries. My hubby LOVES SP fries, so we buy the ones in the freezer section for him. I can’t always find ‘real’ sweet potatoes here (small town in Northern Japan) and the Japanese sweet potatoes are NOT as good as regular ones, so we may have to wait a while to try your recipe.

    p.s. For regular fries, sprinkle them with garlic salt, MMMMMMMMMMMMM MMMMMMMMM GOOOOOOD!

  15. Amie says:

    I bet you could use tapioca starch too!

  16. brie says:

    yes yes yes!!!! accompanying the bbq tonight!!! 🙂

  17. Susan says:

    Nah, sorry, but Hutch’s on the beach in Hamilton couldn’t be beat. Course it was more than a few years ago that I was there…

  18. marilyn says:

    karen i also have had that problem and fing that the temperature of the oven makes a difference as well, it has to be quite hot.

  19. marilyn says:

    ok looked back and saw the temp posted sorry karen shoulda known you wouldn’t leave that out.

  20. Sherry says:

    My hero! I make sweet potato french fries for lunch about 3 times a week. I am so excited to try this I can’t even tell you! How do you come up with this stuff??

  21. Joni Nawrocki says:

    Mmmm! Looks good! I’ve also read that coating them with egg white will give them that crisp texture. 🙂

  22. Erin says:

    This is well timed! We tried to make SP fries on Friday night and like you said, they turned into a mushy mess. Take two will be coming soon, using your brilliant strategy!

  23. Michele says:

    OMG. This is just what I need. My boyfriend (who runs a BBQ joint in a bar) had declared all crispy sweet potato fries to be FAKE since he couldn’t figure out how to get them crispy. Can’t wait to show him this.

  24. Sarah says:

    i do like sweet potato fries, but can we have a recipe on for reals french fries too??

  25. Bill Grigg says:

    And I just happen to have some sweet potatoes, sriracha mayo, some corn starch and even an oven on hand! Suh-weet!

  26. Lisa says:

    This works with butternut squash too, although I think I used regular flour instead of cornstarch…maybe? But you have to cook them a little longer. I also may try this with those cool purple potatoes, because those made crappy fries the one time I tried. it.

  27. Liz S. says:

    I’ve redone my meal plan too. My son LOVES sweet potato fries. This will be a big treat for him. I’ve tried making them before and they were awful!

  28. CourtneyOutLoud says:

    First – I love a woman who enjoys fried foods. Second, great tip about the corn starch!

  29. Sarah P says:

    I have tried a wide range of (baked) sweet potato fry recipes and always end up with soft mushiness. Delicious, but mushy. I can’t wait to try your way!

  30. Sarah P says:

    Hey, ALSO: do you think baking them on parchment paper on a baking sheet would change anything? I don’t have non-stick ones and I’m not big on scrubbing them clean.

  31. Lynn says:

    I like my SP Fries dipped in lazy-gal aioli (Hellman’s/Best Foods mayonnaise with tons of minced garlic and a squeeze of lemon juice). Just about everything is good with garlic mayonnaise, though.

  32. B.J.M says:

    Sound and look yummy! Great idea. Gonna give them a go! I always found the mushy thing disappointing in a sw.-potato-fry too. I was thinking of soaking the cut fries in ice water like is done for good regular fries…but this is definitely less time consuming.
    BTW – the cute dishes are no longer available and havent any ETA either. Whaaa.

  33. Karen says:

    Brenda – Blech. That’s too bad. Also, I do soak my Sweet Potato fries in cold water before cooking them if I have time. I didn’t have too much time this particular day so they were only in the water for a hour or so. ~ karen

  34. Very excited to try this out! Thanks!!

  35. magali says:

    I don’t like this post. I had managed to forget that I wanted french frie cups with matching sauce cups (or was it that I/my boyfriend convinced me that I didn’t need any..?) and now you just went ahead and reminded me just how great they look.

    I will like this post the day I decide to make sweet potato french fries however.

  36. Marti says:

    Hey Karen!

    LOVE sweet potato fries, baby chicks and fried chicken. (There’s an icky question about poor, sweet Lucky buried around here somewhere, but we won’t go there.)

    What is the oven temperature for this, please? Love sweet potato fries. Oops! Said that already.


  37. Karen says:

    Marti ! Sorry .. the temperature is hidden above one of the pictures somewhere. Set your oven to 425. ~ karen

  38. Marti says:

    Thanks much! Luv your blog, btw. 🙂 Bookmarked already!

  39. Gayle says:

    Okay, first. Those are YAMS.
    Second, I’ve been trying for YEARS to get them crispy. How did you figure this out?

  40. Karen says:

    Gayle! Hmm. They were labelled as Sweet Potatoes at the store. They aren’t scaley or anything like a Yam. Why do you think they aren’t the dark skinned variety of sweet potatoes (which are often wrongly called a Yam?) Not being accusatory. Just curious! Do you know things I don’t know? I like to know everything. It’s a downfall. Lemme know! 🙂 I looked up all kinds of recipes and techniques on the Internet, weeded out the ones that didn’t work and combined a couple of techniques that did. It’s that whole “know everything” gene in me. ~ karen!

  41. Jen says:

    I’m making these for my in-laws tonight! My kids have always resisted sweet potatoes. Maybe if they are crispy they’ll enjoy them. Bonus: I’m roasting off an extra tater for my wee!

  42. Karen says:

    Jen – Glad to hear it! Make sure you have a good non-stick pan. If you don’t, add a tiny bit of extra oil to help the sweet potatoes not stick so badly. When you flip them you’ll have to use a spatula to scrape them up regardless. Good luck! ~ karen

  43. office interior design says:

    Great tips…thank you. I love french fries but sweet potatoe fries are pretty good too especially with the right dipping sauce. Can’t wait to try this one.

  44. Cynthia says:

    This Canadian is so proud of you! I’ve always loved you on TV. How is it you get even better in print? And now, as if it couldn’t get better, you share the secret of crispy sweet potato fries on the absolute day I have been bemoaning the limp disasters I keep producing. As a breast cancer survivor I can’t indulge in normal fries as often as I’d like, but these, especially with Sriracha dip, these are going to be my new, healthy, crack. Bless you!

  45. Karen says:

    Thank you Cynthia! Remember … a really good non stick pan and if you don’t have one a touch extra oil so they don’t stick too badly! Good luck. The dip is absolutely delicious! The more Cayenne the better, too. (if you like hot that is) And congratulations on kicking breast cancer’s ass by the way. BREAST CANCER CAN SUCK IT! ~ karen

  46. Gayle says:

    Okay, I just read up on yams and sweet potatoes on wiki, and, well, sweet potatoes can be orange after all. Also, I think I was being a bit rude… sorry. I’m going to try these very soon.
    The funny part is, I was trying to make crispy ones the other day using the broiler, and I thought to myself I should submit an Ask Karen… but I forgot!!

    from wiki:
    In the United States, sweet potato (Ipomoea batatas), especially those with orange flesh, are often referred to as “yams.” In the United States, firm varieties of sweet potatoes were produced before soft varieties. When soft varieties were first grown commercially, there was a need to differentiate between the two. African slaves had already been calling the soft sweet potatoes “yams” because they resembled the yams in Africa. Thus, soft sweet potatoes were referred to as yams to distinguish them from the firm varieties.[10] Sweet potatoes labeled as “yams” are widely available in markets that serve Asian or Caribbean communities.

  47. Karen says:

    Gayle – Don’t worry about it. If I thought someone was wrong I’d be just as vocal about it. I *am* just as vocal about it. 🙂 ~ karen

  48. Nichola says:

    Well I made an attempt but they weren’t quite as crispy as I was hoping for. I think I must have used too much corn starch and maybe not enough oil? Will definitely be trying again though!

  49. Karen says:

    Nichola – You definitely need to coat the fries in oil. And you don’t need a ton of cornstarch. If push comes to shove and you’re having trouble, you can use the same technique in the deep fryer. It’s easier to get them crispy that way. But even in the deep fryer you’ll need to coat them in corn starch. Even in the fryer they won’t come out crispy. Try again and let me know how it goes. ~ karen

  50. Jan says:

    How long do you usually soak them in cold water? And what does the soak do? Thanks!

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